Energy & the Built Environment:
Assessing Renewable Energy Planning in Burlington, Vermont
ARCHNvES
by
MASSACHUSETTS INSTITUTE
OF TECHNOLOLGY
Ethan Lay-Sleeper
JUN 29 2015
B Arch
Syracuse University, 2008
LIBRARIES
Submitted to the Department of Urban Studies and Planning
in partial fulfillment of the requirements for the degree of
Master in City Planning
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
June 2015
@2015 MIT. All rights reserved.
The author hereby grants to MIT permission to reproduce and to distribute publicly paper and
electronic copies of this thesis document in whole or in part in any medium now known or
hereafter created.
Signature of Author:
Sig nature redacted
Sig
Certified by:
Department of Urban Studies and Planning
May 21, 2015
i
Sigr ature redacted
Professor Alan Berger
Department of Urban Studies and Planning
Signa ture red 3cted
Thesis Supervisor
Accepted by:
Professor Dennis Frenchman
Chair, MCP Committee
Department of Urban Studies and Planning
1
Energy & the Built Environment:
Assessing Renewable Energy Planning in Burlington, Vermont
by
Ethan Lay-Sleeper
Submitted to the Department of Urban Studies and Planning
on May 21, 2015 in Partial Fulfillment of the Requirements
for the Degree of Master in City Planning
ABSTRACT
Society's dependence on fossil fuels, spawned during the industrial revolution of the 1 9th
century, increased the physical isolation between the sites of energy consumption, and sites of
energy production. Rapid population growth and urbanization following this period gave rise, in
the
2 0 th
century, to concerns around the impact of humans on the environment. These concerns
precipitated an increased focus on renewable energy, and sustainable development models
present in contemporary urban planning discourse.
Despite the increased focus on urban sustainability, the rapid expansion of renewable
energy capacity and supporting policies, municipal governments in the United States continue to
struggle with incorporating renewable energy systems into the built environment. The primary
challenges concerning this integration rest in the capacity of municipal government to reinterpret
the built environment as a framework for renewable energy, to conduct spatial analysis of the
potential capacity in the built environment, and to synthesize that analysis with municipal
policies in order to develop more robust and specific targets for renewable energy development.
In response to these challenges, I assess opportunities and barriers for renewable
energy development in the built environment, and synthesize established methods of spatial
analysis, renewable energy policy, and project development models, to inform the role of
municipal government in future planning efforts around renewable energy.
To investigate the potential practical applications of this research, I focus on the city of
Burlington, Vermont, which in 2014, earned the status as the first city in the United States to
source 100% of its electricity from renewable sources. I question the replicability of the means
by which Burlington attained this status, whether further opportunities exist for Burlington to
expand its support for renewable energy, and what role the municipal government might
assume in this expansion.
I find the means by which Burlington sources its renewable energy only partially
replicable, but I also find significant opportunities for Burlington to expand support for renewable
energy within its municipal boundaries. I conclude my research by providing my findings to the
city, in hopes that they will strengthen the role of municipal government in renewable energy
planning.
Thesis Supervisor: Alan Berger
Title: Professor of Landscape Architecture and Urban Design
Introduction..............................................................................................4
Energy & the Built Environment
Municipal Planning for Renewable Energy
Implications of Approach
Renewable Energy in Context......................................................................9
Global Renewables
Renewable Energy in the United States
Renewable Energy Policies and Planning
The Cost of Solar
Solar PV Capacity
State Support for Renewable Energy
Energy Planning in Burlington
The Burlington Electric Department
Renewability & Replicability......................................................................22
Supply Resources and Capacity Obligation
Claiming Renewability
The Geography of BED's Renewable Resources
Local and Regional Implications of Burlington's Path to Renewables
Renewable Energy in the Built Environment...............................................
28
Impacts of Energy Forms
Generating Energy in the Built Environment
Barriers in the Built Environment
Operational and Technical Concerns
Collective Action & Project Scale
Precedents.............................................................................................
35
Community Solar Project Models
Solarize Campaigns
Solar Zoning Models
Proiecting Cavacity.................................................................................
47
Spatial Analysis of Solar Capacity
An Alternative, Targeted-Model
Spatial Description of Burlington
Spatial Analysis of Structures
Spatial Analysis of Open Space
Applications for Municipal Planning............................................................58
The Role of the Municipal Government
Identification of Stakeholders
Strengthening Policies for Solar
Developing a Project Model
Leveraging RECs for New Capacity Planning
Conclusion.............................................................................................64
Reference Maps & Diagrams......................................................................69
79
Methodoloav...........................................................................................
83
N otes......................................................................................................
Introduction
Energy & the Built Environment
Urban areas are composed of cities, towns, and suburban development; they
function as an organizing framework for the human population. Urban areas house
more than 50% of the current global population, up from only 13% in 1900.1 Urban
areas account for between 71 % and 76% of global C02 emissions, and consume
between 67% and 76% of total global energy.2 Buildings within these urban areas
account for 32% of global energy use, and 19% of greenhouse gas emissions. Urban
areas can be understood as a layering of systems, including buildings, transportation
and energy infrastructure, industry, and the natural environment. These systems
represent massive amounts of energy inputs. These inputs include the embodied
energy required to construct the systems, the operational energy required for heating,
cooling, transmission of energy, and maintenance, as well as the transportation energy
required for moving people and goods within these systems.
The type of energy used and rate of consumption varies for urban areas
depending on multiple geographic, cultural and economic variables. However, tracing
the history of energy types and rates of consumption from pre-industrial societies
through contemporary urbanization, establishes a clear evolution toward the dominance
of fossil fuel energy, higher rates of energy consumption, and increased environmental
impacts associated with this energy use.4
After almost two centuries of evolving understandings and approaches to
industrialization and energy in the built and natural environments, there is a clear
trajectory toward design and planning processes that seek to reduce the negative
4
impacts of humans on the earth. However, there are still questions about how urban
areas can participate in this effort, and the role of planning and design in facilitating this
participation. One common trend is the growing interest in sustainability5 and its
relationship to energy conservation and renewable energy.
Sustainability oriented planning agendas now exist in major cities around the
world: Chicago, New York City, Boston, Portland, Austin, Boulder, San Francisco, Santa
Monica, Zurich, Geneva, Lyon, Paris, Berlin, Munich, Hamburg, Dusseldorf, Koln,
Lisbon, Oeiras, Oporto, Barcelona, Madrid, Singapore, and the list goes on.6 These
cities have invested large quantities of time and money developing their various
environmental action plans, green planning initiatives, climate action plans, sustainable
development principles, and other planning agendas with similarly constructed verbiage.
Even with agendas of sustainability, these cities continue to rely on a global energy
system dominated by fossil fuels, with wind, solar, geothermal and modern biomass
only comprising 1.2% of final global energy consumption.7
Addressing this issue will require global participation across a multitude of
political, economic, cultural and geographic factors, and is beyond the scope of this
thesis. What this thesis focuses on, is the potential role of municipal government in the
incorporation of renewable energy production into the built environment.
Municipal Planning for Renewable Energy
Despite the increased focus on urban sustainability and the rapid expansion of
renewable energy capacity and supporting policies in recent years; municipal
governments in the United States continue to struggle with incorporating renewable
energy systems into the built environment. The primary challenges concerning this
incorporation rest in the capacity of municipal government to reinterpret the built
environment as a framework for renewable energy, to conduct spatial analysis of the
potential capacity in the built environment, and to synthesize that analysis with
municipal policies and project development models.
In response to these challenges, this thesis assesses opportunities and barriers
for renewable energy development in the built environment, and synthesizes
established methods of spatial analysis, renewable energy policy, and project
development models, to inform the role of municipal government in future planning
efforts around renewable energy. To investigate the potential practical applications of
this research, this thesis focuses on the city of Burlington, Vermont, which in 2014,
earned the status as the first city in the United States to source 100% of its electricity
from renewable sources. Investigating the means by which Burlington attained this
status, provides insight into the relationship between municipal planning and regional
energy markets. It also reveals further opportunities for Burlington to expand its support
for renewable energy within the built environment, through the synthesis of spatial
analysis and policy at a local level, and leveraging the value of renewable energy in a
regional context.
The growth and increasing value of solar photovoltaic (PV) technology and its
suitability for integration into the built environment represents a major opportunity for
renewable energy in Burlington. To integrate this technology into the built environment,
Burlington needs to redefine its existing structures as a framework for renewable
energy. This requires that roofs be valued not only as surfaces for protection from the
elements at the individual level, but as surfaces for collection of solar energy at the
scale of the city. To support and articulate this new understanding of the built
environment, spatial analysis using GIS software provides Burlington with the ability to
quantify the total surface area suitable for solar PV. This quantification can serve as the
base material for economic and spatial planning initiatives in support of targeted
renewable energy development at the scale of the city. By synthesizing spatial analysis
and regulatory policies within the built environment, Burlington can support renewable
energy development in more calculated and spatially deterministic ways that exploit
economies of scale and collective action.
This synthesis of quantitative spatial analysis, regulatory policy, and scale of
action focused around the solar functionality of urban surfaces, increases the possibility
for decoupling individual sites of production from their necessary sources of investment.
In this way, the total solar surface area of Burlington can be optimized for maximum
production, and investors can benefit from the renewable energy regardless of the
geography or ownership of the surface on which it is installed.
Implications of Approach
The synthetic approach to renewable energy planning outlined in this thesis
argues for a shift in the dynamic between cities and energy. It seeks to add value to
urban areas as producers of energy, in order to mitigate their role as the world's primary
consumers of energy. Addressing this issue in the existing built environment confronts
the social, cultural, economic and political centers of civilization as drivers of change,
and as examples for future urbanization.
The research and investigation undertaken in this thesis provide a preliminary
outline for how one city might begin to address these issues at the scale of its own built
environment. This thesis does not claim to provide a comprehensive plan for renewable
energy, but rather a series of precedents in solar policy and project development, that
might be adapted for Burlington, and made more spatially deterministic through the
integration of GIS analysis. By adopting regulatory policy based on quantitative spatial
analysis, Burlington can prepare itself for future development of renewable energy, and
potentially play a role in instigating this development.
Before investigating the means by which Burlington transitioned to 100%
renewable sources for its electricity, and before assessing opportunities for Burlington to
increase its support of renewable energy, the following section establishes the broader
context of renewable energy. It synthesizes data from various institutions and agencies
to show the expansion of renewable energy technology and policy that occurred over
the last 40 years. It establishes wind and solar PV generation as the dominant forms of
new renewable capacity, and shows that the United States is lagging in this
development on a per-capita basis. This section discusses the costs of a potential
transition scenario for the United States, where solar PV and wind generation replace
fossil fuels. It also positions the state of Vermont in the broader context of solar PV
development.
Renewable Energy in Context
Global Renewables
The cultural understanding around renewables is evolving from the singular
viewpoint of renewables as just another energy source, to include their impact on
energy security, health and environmental benefits over nuclear and fossil fuels, their
potential for mitigating greenhouse gas emissions, and also the opportunity they
represent for new jobs and education.8 In early 2014, 144 countries had renewable
energy targets, with 138 of those also having implemented renewable energy support
policies.9 Thousands of cities and towns across the world also have renewable energy
targets, plans and policies, which are often more-ambitious than national policy, and
point to the importance of municipal leadership for the future of renewable energy
development.1 0
Despite these efforts, renewable energy still only accounts for approximately
20% of total global energy consumption. China, the United States and Germany are
leaders in total renewable energy capacity, although other countries like Denmark have
higher per-capita capacities." The following charts illustrate total global energy
consumption and capacity relative to various sources of renewable energy:
Total Energy Consumption
All Renewables
Modern Renewables
Blofuels
Re
Ai
a les
lFuels
RrealsTraditonal
M er SBinaWS
Reeal
Power
12%
47%
Nuclear
3%
Hydro
38%
Figure 3: 2013 Total Global Energy Consumption by Source
Source: REN21. 2014 Renewables Global Status Report (Paris: REN21 Secretariat).
9
Bloas/got
hoe
42%
The charts below show the role renewable sources play in electricity production; the
primary differences between the global consumption charts and the electricity
production charts are the relationships between biomass and hydro power, with hydro
playing a much larger role in electricity production.
Total Electricity Production
Renewable Electricity
Fuels &
Fossil
FoslFes&Sl
Nuclear
All
Renewable.
Power
Solar PV
3%
Geothermal,
CSP, Ocean
2%
418%
Figure 4: 2013 Total % of Global Electricity Production by Source
Source: REN21. 2014 Renewables Global Status Report (Paris: REN21 Secretariat).
In 2013, the world produced a total of 560 Gigawatts (GW) of electricity from renewable
sources not including hydro. The relationship between global capacity, the European
Union, BRICS (Brazil, Russia, India, China and South Africa) and individual countries is
illustrated below:
GW Capacity
GW Capacity
560
118
3-----93----------------------------78
100 GW --
-
--World
EU-28
-
--
Spain
Germany
China
U.S.A
BRICS
Figure 5: 2013 Non-Hydro Renewable Capacity
Italy
India
Source: Adapted by author from: REN21. 2014 Renewables Global Status Report (Paris: REN21 Secretariat).
The top 6 countries account for approximately 70% of total renewable capacity globally.
By energy source, the leading contributors to global renewable capacity are solar PV
and wind energy, which comprise close to 80% of this capacity.12 Between 2000 and
10
2013, global wind capacity increased from 17GW to 318GW; between 2004 and 2013,
global PV capacity increased from 3.7GW to 139GW.13
Renewable Energy in the United States
The rapid expansion of wind and PV capacity reflect increasing cost parity
between renewables and fossil fuels, which has led to significant increases in total
dollars invested in renewables in the United States over the last decade:
U.S.A Investment in
Renewables
53.4
33.6
28.223.5
39.7
35.9
35.8
117
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Figure 6: Total Annual Investment in Renewables, in Billion USD
Source: REN21. 2014 Renewables Global Status Report (Paris: REN21 Secretariat).
Even with the significant increases in investment and development of renewable
energy, there are still challenges, not the least of which is that fossil fuels continue to
receive massive subsidization, far outweighing that of renewables. In 2011, petroleum
products, natural gas and coal received $480 billion in subsidies globally before taxes;
after taxes, factoring in negative externalities the global value of these subsidies is
calculated to be closer to $1.9 trillion.14 Energy subsidy reform is a complex issue that
could create significant positive change, but also lacks public support, and raises
governmental concerns around inflation.1 The countries of Denmark, Germany, and
Spain have taken unprecedented national leadership in promoting and developing
renewable energy through policy reform and direct investment.1 6 The fact that Germany,
11
which is the size of Montana, has developed 78GW of renewable capacity, while the
entirety of the United States has only developed 93GW of renewable capacity, implies
that United States has an impressive amount of work left to do. In addition to lagging
behind other nations on a per-capita basis of renewable energy development, the
United States is a global leader in per-capita consumption of non-renewable resources
like petroleum, natural gas and coal. 17
To address the current situation around energy in the United States, in 2010, the
Civil Society Institute released an evaluation of a strategy for the U.S. electric industry
to reduce carbon emissions and improve public health, through a large-scale transition
to energy efficiency, and renewable energy. The evaluation draws on growing concerns
over health and environmental risks around fracking, water consumption for cooling in
power plants, and new EPA regulations for greenhouse gas emissions.1 8 The study
compares a business as usual (BAU) scenario to a transition scenario, and assesses
the potential financial implications using a cost benefit model and sensitivity analysis. In
the transition scenario, all coal fired power plants and 25% of nuclear plants are retired
by 2050, natural gas consumption is lower than in 2011, and energy efficiency and
renewable energy make up the difference.19 The net annual cost impacts of the
transition scenario are evaluated in by decade, and range from savings of $18 billion in
2050, to costs of $9 billion in 2040, with the overall conclusion that the transition
scenario will likely be less expensive than BAU.20 This is especially significant in
consideration of the fact that the BAU scenario doesn't include carbon costs or carbon
reductions, which would further increase savings of the transition scenario.2 1 To achieve
this transition at the projected costs, the model assumes that solar PV grows from 2-
14GW under BAU to 384GW, and that onshore and offshore wind grows from 38-64GW
under BAU to 188GW. To accommodate for the intermittency of these resources, the
scenario also relies on increased storage capacity.
The largest increase in renewable
capacity identified in the study is in distributed generation from solar PV. While solar PV
is by no means the only solution, it is one that can be readily adopted by municipal
governments, and has more direct implications for the built environment and the
discipline of city planning.
Renewable Energy Policies and Planning
For municipal government to participate effectively in this planning process, it is
important to position cities in the context of broader federal and state policies that
support renewable energy. Policy plays a significant role in making renewable energy
economically viable, especially when it comes to PV. The main components for solar PV
policy focus on financing the installation of projects, ensuring that the electricity
produced is sold at certain prices, and generating renewable energy credits. A major
contributor to project financing is the federal Investment Tax Credit (ITC) for solar. This
credit has been in effect since 2008 and is set to expire at the end to 2016. It provides a
30% tax credit on the installed cost of solar projects for both commercial and residential
properties. One hurdle for certain municipal projects is that cities don't have tax
appetites, so to take advantage of the tax credits cities need to work with the
commercial sector to negotiate contracts where both parties benefit.
Net metering is a policy tool that incentivizes distributed energy generation by
requiring utilities to purchase excess power generated by customers at a rate slightly
higher than retail. The system is monitored by utility companies through meters that
keep track of the energy consumed and produced by a net metered customer; net
metering also bypasses the need for customers to install expensive battery banks for
storage, as excess electricity is fed back into the grid. Currently, 44 states have
mandatory statewide net metering regulations.2 3
A Renewable Portfolio Standard (RPS) is a state-level regulatory mandate that
requires a certain percentage of a state's electricity portfolio to come from renewable
sources such as solar, wind and biomass. These requirements typically increase
gradually to allow for new renewable capacity to be developed. As of February of 2015,
31 U.S. states had mandatory renewable portfolio standards, 8 states had voluntary
renewable energy standards or targets, and only 13 states had no standard or target.
Renewable Portfolio Standards also increase the demand for Renewable Energy
Certificates (RECs), which are another financial mechanism designed to further
strengthen the market for renewable energy. For every megawatt hour (MWh) of
electricity produced by renewable sources, one REC is generated. RECs can be sold
with the actual electricity or separately. Purchasing RECs is one way for states to meet
the requirements of Renewable Portfolio Standards. There are generally two classes of
RECs, Class I and Class 11. Class I RECs typically have higher values and are
comprised of new generation such as solar PV, wind and biomass, while Class II RECs
typically have lower values and are comprised of older hydroelectric facilities. RECs are
tracked by a series of regional systems throughout the U.S. For instance, the New
England Power Pool Generation Information System (NEPOOLGIS) provides an online
system that tracks production and sales of RECs in the 6 New England States. In
14
addition to RECs there are Solar Renewable Energy Certificates or SRECs, which focus
solely on PV, and tend to have much higher values than RECs.
After purchasing
RECs or SRECs, the owner may choose to retire these in order to claim renewability
and meet required or voluntary renewable portfolio standards.
Another major driver of new PV development in the United States has been the
steady and significant decline in the installed price of solar over the last 15 years. This
is primarily attributed to improved technology and lower module costs, but there are also
other factors that influence installed cost.
The Cost of Solar
In 2014, the Lawrence Berkley Laboratory, in collaboration with the U.S.
Department of Energy (DOE), released a historical summary of the installed costs of
solar PV from 1998-2013. The study makes the following conclusions about efficiencies
of scale, trends in installed costs, as well as estimates for future costs. Nationally, PV
installations for new residential construction have shown consistent savings relative to
retrofit projects, in 2013 the difference was $0.9/watt. When comparing roof mounted
systems to ground-mounted systems, size is a key factor; typically roof mounted
systems are more economical in systems less than 10 kW ($0.8/watt), but this margin
decreases as system size increases, and in 2013 ground-mounted projects over 1,000
kW saved $.07/watt over roof-mounted systems. The report attributes declining costs in
installation over the last decade to a steady decrease in PV module prices (despite
diminishing ITCs), but notes that in 2013 and 2014 installed costs continued to drop
despite steady or increasing module costs. This is attributed to new efficiencies in labor
and installation procedures. Prices in modules are not expected to decrease, so further
price reductions are expected to come from increased innovation in non-module
components and installation methods. These reductions are seen as attainable, based
on comparisons between installed costs in Europe relative to the United States. In 2013
the installed cost before taxes was $2.1/watt in Germany, $2.7/watt in the United
Kingdom, $2.9/watt in Italy, $4/watt in France, and $4.4/watt in the United States. To
reduce the soft costs associated with installation, the report suggests the development
policy that fosters competition within the delivery infrastructure, and specific targeting of
permitting, interconnection and research.26
Even though growth in solar has increased due to technological improvements
and declining costs, it is still more expensive than most conventional energy sources.
Solar also benefits from a variety of fiscal and regulatory incentives, and in order to
achieve large-scale deployment, solar still needs to overcome a variety of technical,
financial, regulatory and institutional barriers, all of which necessitates increased policy
support for solar.2 7
Solar PV Capacity
As a result of declining costs and support on behalf of state and federal
government, electricity generation from solar in the U.S. increased by a factor of 5
between 2008 and 2012.28 In terms of overall PV capacity, California has long been a
leader, followed by New Jersey and Arizona. The top 10 states by total PV capacity are
shown in figure 7 below.
16
PV Capacity (MW)
3,500,000
--
-----------------------------------------
------------
-
-
-
2,500,000
2,000,000
--
--
-
1,500,000
----
------
-- -------
- - - --
----
3,000,000
--
---- -------- ---
-- ----
---
100,000-
m
CA
NJ
AZ
MA
NV
-
- -NY
PA
TX
-U
-
--
-
5ooooK
NM
CO
Figure 7: Total PV Capacity, in MW
Source: National Renewable Energy Laboratory, Open PV Project.
The vast disparity between geographic region and total PV capacity help to support the
argument that state policy plays a major role in promoting solar development. Similarly
to total renewable energy at a global scale, these ranking shift if they are considered on
a per capita basis. Figure 8 shows Arizona and New Jersey as leaders in per capita PV
capacity, followed by California, Nevada and New Mexico similarly to the graph of total
PV capacity. What is interesting about the per capita graph is that smaller states like
Delaware and Vermont rank very closely to larger and sunnier states.
PV MW Per Capita
-
-
-
--
--
- -
-
0.060
-
-
-------
- -------
-
0.020--
-
-
0.080
0.040
-
-
- - -
-
--
0.100
--
-
0.120
--
-
-
------
-
0.180
0.160
0.140
AZ
NJ
CA
NV
NM
DE
MA
VT
CT
CO
Figure 8: Total PV Capacity Per Capita, MW
Source: National Renewable Energy Laboratory, Open PV Project; United States Census, 2010.
The combination of Vermont's relatively high rate of PV capacity per capita, combined
with fact that Burlington, Vermont is the first city in the United States to have
17
transitioned to 100% renewable sources for its electricity, suggests that there are
opportunities to learn from Vermont's state and local policies.
State Support for Renewable Energy
Vermont is not a major producer or consumer of electricity at a national scale; it
also lacks fossil fuel resources, with hydro and other renewables accounting for 99.5%
of in-state electricity generation.2 9 In 2012, Vermont also became the first state to ban
fracking. These factors combined, make in-state renewable energy development one of
the Vermont's only options for reducing its reliance on imported energy. This geographic
and resource-related reality, combined with policy has no doubt contributed to the rise
of renewable generation in the state.
Stastically, Vermont adheres to national trends with respect to efficiencies of
scale, with system sizes from 10-100 kW coming in at consistently lower cost per watt
than systems smaller than 10 kW. In Vermont, the median price for systems under 10
kW in 2013 was $4.7/watt, and $4.2/watt for systems between 10-100 kW. The installed
costs in Vermont have dropped from over $10/watt in 2004.30 For a typical 4 kW
residential installation in Vermont, the expected payback period is between 9 and 10
years.3 1 The Vermont ITC parallels the timeline of the federal ITC, offering an additional
7.2% tax credit to commercial, industrial and agricultural sectors. Vermont also offers
sales and property tax exemptions, and several low-interest loan programs that assist in
financing solar PV installations.
Vermont allows group net metering, which distributes the benefits of net metering
between groups of customers within a utility's service area. Vermont's net metering law
caps the size of projects at 500 kW, and also caps the total capacity of net metering
within individual utility service areas at 15% of their peak load. Utilities are required to
purchase excess generation from net metered systems at $.20/kWh for systems 15 kW
or less, and $.19/kWh for systems greater than 15 kW. Customers in Burlington typically
pay $.14/kWh, so the higher purchase price provides additional incentive for customers
to install solar PV. In summary, Vermont supports renewable energy and solar PV in a
variety of ways that parallel efforts in other states, including the implementation of an
RPS. In addition to participating in best practices for renewable energy policy, Vermont
also has developed ambitious goals for statewide renewable energy development.
Vermont aspires to obtain 90% of its total energy from renewable sources by
2050 in order to reduce its greenhouse gas (GHG) emissions. In 2011, the state
released a 336 page Comprehensive Energy Plan (CEP) outlining a multitude of
strategies for achieving this goal, while protecting Vermont's natural resources and
working landscape. Statewide electricity consumption accounts for .5 million megatons
(MMt) of C02 emissions annually, while residential, commercial and industrial fuel use
accounts for 2 MMt, and transportation accounts for 3.5 MMt.3 2 In 2009, electricity
comprised 37.5% of total energy consumption, transportation fuels comprised 34.4%,
and heating fuels comprised 28.1%.33 As such, the CEP advocates for increasing
electricity generation and transmission capacities to produce lower-emissions
alternatives to fossil fuels, and to provide the necessary infrastructural capacity for
electric vehicles. After an evaluation of the economics, public sentiment and land use
considerations, the CEP proposes that new electricity generation be met primarily
through increased capacity provided by solar, wind, and combined heat and power
(CHP) facilities powered by natural gas and biomass.34
These state-level factors in policy and planning help to explain Vermont's high
per capita rankings in energy efficiency and renewable energy, and these certainly
influenced and helped the city of Burlington in its transition to renewable electricity, but
municipal policy and planning also played a large role.
Energy Planning in Burlington
The city of Burlington has a history of supporting as well as developing
renewable energy resources. Renewable energy and efficiency have been incorporated
into a number of municipal planning efforts, including:
*
"
"
"
"
Burlington's Municipal Development Plan
Burlington's Climate Action Plan
Burlington's District Energy Study
Burlington's Comprehensive Development Ordinance
The Burlington Electric Department's Integrated Resource Plan
Burlington's energy plan (a component of the Municipal Development Plan) sets policy
goals of educating citizens on the benefits of public utility ownership, and renewable
electricity generation. It also identifies local energy self-sufficiency as an important
component of Burlington's future sustainability.35 The climate action plan provides a
framework for measuring and reducing greenhouse gas emissions, and establishes
goals for compact development, transportation, urban forestry, energy efficiency in
buildings, renewable energy development, waste reduction and recycling. 36 Burlington's
district energy study provides analysis and recommendations for utilizing existing
energy resources to develop a Community Energy System (CES). The study focuses on
the potential for improved energy efficiency through interconnecting the McNeil
generating station with the campuses of the University of Vermont Campuses and
Fletcher Allen Health Care.3 7 Burlington's comprehensive development ordinance (or
zoning ordinance) clearly establishes the encouragement, conservation, utilization and
development of renewable energy resources in the intents and purposes section of its
general provisions. 38 The Burlington Electric Department's Integrated Resource Plan
aims to meet the public's need for energy services at the lowest cost, including both
environmental and economic costs. The plan analyzes potential resource decisions,
proposes strategies for resource acquisition, and must be approved by the city and
Public Services Board. 3 9 The Burlington Electric Department is the third-largest of
Vermont's 18 electric utility companies, and plays a critical role in shaping and
implementing energy planning in Burlington.
The Burlington Electric Department
The Burlington Electric Department (BED) is a municipally owned utility company
that manages the power purchase agreements and distribution of electricity for the city
of Burlington. As a public power entity BED makes its decisions through an open
process and public input. As such, it has been and continues to be a goal for BED to
provide power that is as clean and as locally produced as possible, while maintaining
affordability. BED helped to pave the way for renewable energy through the construction
of the McNeil wood-powered electric generating facility, which was constructed in 1984.
Between 1989 and 2011 BED invested over $38 million in energy efficiency programs;
Burlington's electricity use in 2011 was 4.7% lower than in 1989, which equates to
approximately $10 million in savings per year.4 0 BED is currently Vermont's largest
municipally owned electric utility, serving over 19,000 customers in a 16 square mile
area.
In 2010, BED received $69 million in federal grant funds through the Smart Grid
Investment Grant. This enabled increases in efficiency through dynamic billing, better
service analytics and easier integration of renewables. In recent years BED made
significant steps in transitioning to renewable sources, the most recent of these steps
includes the acquisition of the Winooski One hydroelectric facility in September of 2014.
BED provides net metering as a way to encourage private solar PV development within
the municipality; and also contracts for PV generation with several housing projects and
city schools. BED negotiated a lease on the roof of the parking structure at Burlington
International Airport, and constructed a 576 kW facility that BED owns and operates as
of January, 2015. BED continues to pursue contracts for renewable energy from wind
and solar resources within Burlington and the state of Vermont.
Renewability & Replicability
The following section discusses the means by which Burlington currently claims
renewability for its electricity, and assesses the extent to which these means are
replicable by other municipalities.
Supply Resources and Capacity Obligation
To understand Burlington's transition to renewable electricity, it is important to
examine BED's responsibility to its local customers as well as to the regional electric
grid. BED needs to provide electricity not only for the residents of Burlington, but also
needs to contribute capacity to ISO-NE to ensure reliability of the regional electric grid.
This is referred to as BED's capacity obligation, and is based on the load ratio share of
the total ISO-NE capacity requirement. The requirement is a percentage of BED's load
at the time of the annual peak load. The peak load usually occurs in July, and even
though BED peaks at around 65 MW, its capacity obligation is to ISO-NE is 85 MW.
BED meets its municipal energy needs through a series of energy purchase contracts
with approximately 15 generation facilities throughout the Northeast.4 1 However, not all
of these 15 facilities count toward the capacity obligation due to ISO-NE requirements
and the intermittency of renewable energy. To meet obligations to ISO-NE, BED
purchases capacity through the ISO-NE Forward Capacity Market (FCM). In 2015 BED
expects to purchase 41.5% of its capacity requirements in this way, and anticipates that
unless new capacity is developed, this number will remain relatively constant. While
BED's capacity obligation doesn't contribute to its ability to claim renewability for supply
resources, it does represent a significant cost. Cost of service is a major component of
BED's declared responsibility to its customers, and has played an important role in
directing the utility's support of and transition to renewable energy.
The interplay between flows of energy and money at the local and regional
scales has played an important role in Burlington's energy transition. BED achieved this
transition through a series of long-term initiatives in energy efficiency, expanding utilityownership of renewable energy generation, investing in new renewable energy
generation, purchasing power from renewable sources, and finally, through the sale and
purchase of Renewable Energy Credits (RECs) in a regional marketplace.
Claiming Renewability
BED has steadily increased its ability to claim renewability by contracting with
more renewable energy sources, while at the same time stabilizing rates through the
sale of RECs. BED is awarded Class I RECs for contracts it maintains with renewable
generation sources. BED sells these RECs to other entities and then purchases lowercost Class 11 RECs which it then retires to regain its claim to renewable energy.
In 2011, BED purchased 46% of its electricity from renewable sources, and sold
the associated Class I RECs to stabilize rates thereby reducing its claim to renewability
to 12.6%. BED then purchased less-expensive Class 11 RECs to reclaim its original 46%
renewability. BY 2013, BED increased its purchases of renewable supply resources so
that before selling its Class I RECs, it could claim that renewable sources provided 95%
of its electricity. In 2013, selling these RECs provided BED with revenues close to 20%
of its cost of service, but lowered the percentage of renewability it could claim to 39%.
With the revenue from selling the Class 1 RECs, BED was able to both control rate
increases and purchase enough Class 2 RECs to reclaim 100% renewable electricity.
The transactions of supply resources and RECs for 2013 are shown below in figure 9.
Renewability Prior to REC Transactions
comincklicu
al3-%
24%
9a%
1
Renewability after REC Sales
Renewability after REC Purchases
0
40IJ OA7%AS
G6w
6.040
OHM
2.67%
320%
co67m6.73%
Figure 9: Renewability and REC Transactions for Burlington Electric Department
Source: Adapted by author from Burlington Electric Department, where we get our power, 2013.
24
As BED acquired more renewable supply resources, the price of Class I RECs
increased significantly, along with BED's revenue from REC sales. Figure 10 shows the
increasing prices BED received for RECs from the McNeil plant, wind and other sources
between 2013 and 2015, as well as the total sales from those sources between 2011
and 2015.
REC Prices (BED)
mMcNeil
a Wind
REC Sales (BED)
$12,000,000
$10,000,000
Other
$8,000,000
$8,000,000
Other
Wind
McNeil
$2,000,0
$4,000,000
2013
2014
2011
2015
2012
2013
2014
2015
Figure 10: REC Prices and REC sales by Burlington Electric Department
Source: Burlington Electric Department, Annual Budget Projections 2013-2015.
The demand created for RECs by the Renewable Portfolio Standards of other New
England states has enabled BED to stabilize its own electricity rates, while still claiming
renewability. Currently, the state of Vermont has a voluntary RPS which will become
mandatory in 2017 and require retail utilities to provide 50% of their electricity from
renewable sources. Vermont's RPS will increase by 4% annually until it reaches 75% in
2032.4 In this regard, Burlington is already well ahead of schedule, in part because of
its early investment in the McNeil generating station in the 1980s. However, as
Vermont's RPS become more stringent, demand for both Class I and Class I RECs will
increase, and eventually more renewable capacity will need to be developed. Where
this capacity is developed will depend on the availability of natural resources and
geography in the case of biomass, wind and hydro, but for solar PV it will depend more
on land use planning and financing models. This new capacity will require significant
25
financial resources in the short-term, but has the potential to produce long-term
economic benefits for the communities in which it is located. In order to assess potential
sites for new renewable energy capacity, it is important to first understand the
geography and extent of existing resources.
The Geography of BED's Renewable Resources
For supply resources purchased through the ISO-NE Exchange, utilities typically
assign a ratio of nuclear, coal and gas based on the average regional mix, thereby
giving a general geographic extent to those resources. However, for thel5 energy
resources for which BED has direct contracts, it is possible to more accurately identify
the sites of production.
In accordance with Rule 5.200 Notification of Power Supply, BED is obligated to
provide a description of its power sources to the Vermont Public Service Board and the
Department of Public Service. The 2015-2019 edition of this report was submitted on
January 3 0th, 2015, and identifies BED's power resources by geography and MWh. In
keeping with BED's 2012 Integrated Resources Plan (IRP), BED's power sources show
a commitment not only to renewable energy, but to local generation facilities, with 11 of
the 15 sources located in Vermont, and 13 qualifying as renewable resources. Together
these 13 renewable resources are projected to provide between 300,000 MWh and
375,000 MWh of annual supply resources between 2015 and 2020.4 These resources
will meet or exceed the forecasted system load starting halfway through 2015. The
largest single contributor to BED's supply resources is the McNeil biomass facility
located in Burlington. The remaining supply resources are composed primarily of a mix
of wind and hydro power, with a much smaller proportion coming from solar. The
following diagrams indicate the geographic extent of these renewable resources and
their respective capacities. Several caveats are that while Burlington only draws 8% of
its electricity from Hydro Quebec, it doesn't identify a specific facility, and thus more
Hydro Quebec facilities are shown than BED actually draws resources from. This is also
the case for BED's contracts through Vermont's Standard offer program which provides
an even smaller percentage of BED's resources from a number of distributed sites, but
is only represented by one site in the following supply resources diagram. All other
sources can be traced to specific singular facilities. M See d-agrasn
&
7
Local & Regional Implications of Burlington's Path to Renewables
A better understanding of the geography and quantity of Burlington's current
supply resources and capacity obligation helps to put future decisions about developing
new resources in perspective at both local and regional scales. According to the
Vermont Department of Public Service, in 2011, Vermont received approximately 20%
of its total energy from renewable sources, and imported 40-45% of its total electricity
(including renewable sources) through a combination of direct contracts and short-term
purchases from ISO-NE. 45 In the context of the statewide goal of acquiring 90% of its
energy from renewable sources by 2050, there is still a large gap to be filled through the
development of new renewable resources in the next 35 years.
There is no doubt that Vermont will continue to rely on and contribute to the
regional network of renewable energy providers in the Northeast, but there are also
opportunities to take steps toward developing new renewable energy generation
capacity in-state. It is important to understand the efforts in Burlington as a dynamic
feedback between local and regional forces that depend on and affect one another. By
purchasing renewable energy sources locally and regionally, BED is helping to support
renewable energy development at multiple scales. By participating in the regional REC
market BED is simultaneously providing supply and demand, while producing local
economic benefits and regional environmental benefits. The development of new
renewable capacity should therefore be both a regional and municipal priority. Since
municipal governments can't directly take advantage of state or federal ITCs 46 , they
need to develop new approaches for promoting renewable energy.
Different municipalities will have different options in terms of the ways they can
act, based on population, geography, density, and form of the built environment. As
Vermont's largest municipally owned utility, and as a national leader in the transition to
renewable energy, BED is uniquely positioned to pioneer new approaches in municipal
planning for renewable energy. A first step is to identify what types of renewable energy
are appropriate for the built environment, and how the municipal government can better
prepare itself to promote and incorporate new capacity.
Renewable Energy in the Built Environment
Impacts of Energy Forms
The 100 largest metros of the United States comprise only 12% of the nation's
land area.47 In this regard it is unrealistic to expect renewable energy development to
remain confined to previously developed areas. Renewable energy projects need to be
sited in both developed and non-developed areas in order to provide enough renewable
energy for the future. However, in the context of the built environment, there are
demonstrated advantages of installing distributed generation that reduces peak demand
and increases energy security.
There are a number of renewable energy options that any community can
consider, however some have more impact on the organization of the built environment
than others. Biomass generation facilities for instance, exist as singular structures that
can be sited anywhere that permits industrial functions. Wind turbines obviously need to
be sited in windy areas, which immediately rules out certain places. They also carry
spatial and political implications for the built environment; the first of which is that tall
buildings can obstruct wind patterns, the second of which is that even in remote areas,
wind turbines are met with political opposition grounded in concerns over aesthetics,
real estate values, environmental degradation and public health.
Siting renewable energy projects in developed areas decreases the likelihood
that they will disrupt habitat, reduce availability of prime farmland, or contribute to
fragmented development patterns. These concerns are especially paramount in the
State of Vermont, where a high cultural value is placed on the state's natural beauty.
Negative cultural perceptions of renewable energy plagued installations of wind projects
in Vermont in recent years, and a dramatic increase of multi-acre solar arrays on open
lands is also spurring public opposition over aesthetic concerns. A study from 2014
shows that perceived risks of siting renewable energy in Vermont outweigh perceived
benefits by a factor of 2.67.48 Incorporating PV into the built environment presents less
of a perceived risk for Vermonters, and has the potential to increase public awareness
and acceptance of renewable energy projects in general, and to enhance the state's
capacity to transition toward its goal of 90% renewable energy by 2050.
Solar thermal and solar PV can be integrated directly into the built environment,
and their installed efficiency depends heavily on spatial factors such as land use
considerations for open space, building height, orientation and roof integrity, and
shading caused by other buildings, trees and topography. Solar installations on
buildings are generally innocuous and tend not to attract the political opposition of morevisible sources of generation. Paradoxically, solar in the built environment-especially
building integrated PV-presents less of a political risk, but is more-dependent on the
spatial configuration of buildings for its efficient operation. With respect to these
assertions about renewable energy generation, not only is solar PV more likely to be
accepted in developed areas, but its implementation carries greater implications for the
spatial reorganization and adaptation of the built environment.
Generating Energy in the Built Environment
At the municipal level, there are certain advantages to installing generation
capacity behind the meter, within the boundaries of the municipality. If a resource is
installed behind the meter (BTM) it contributes directly to reducing the load within a
distribution system, it is not technically counted as capacity and doesn't enter the
regional transmission grid. The primary impact that BTM generation can have for utilities
like BED is in reducing the peak load. By reducing the peak load, the capacity obligation
to the regional grid (ISO-NE) can be reduced, thereby reducing the amount of capacity
a utility needs to purchase from the FCM. 49 In this sense, utility-owned and operated
BTM installations can provide revenue through sales of electricity and potentially RECs,
while also reducing capacity obligation expenses. The installation of solar PV as BTM
capacity can have an added advantage as the peak-energy produced by solar PV often
aligns with the peaking demand of municipalities in warm summer months (when there
is more AC use, but also more sun). With that said, officials at BED have acknowledged
peak consumption may be shifting to later in the day, in which case the role of solar PV
in reducing peak demand would need to be integrated with storage solutions. Other
arguments for BTM PV include the generation of local jobs, energy security, and longterm economic benefits for the host community and less strain on transmission grids
during peak hours.
Barriers in the Built Environment
Despite the various arguments for increasing renewable energy generation within
the built environment, numerous barriers exist in terms of cost, operational concerns,
policy, and collective action. Even with dropping installation costs, and the availability of
financial incentives, installing solar PV still requires a significant amount of planning and
access to capital. Solar PV is typically a long-term investment, the economic returns on
a system depend on a multitude of factors, including electricity consumption, cost/kWh,
local incentives, and the size of the system. The ways in which ownership and benefits
from a project are structured have implications for investors, utility companies and
customers. There can also be tension between state-level net-metering regulations and
the actual market value of PV for utility companies.
For instance, if BED only values PV at 12-14 cents per KWh, but has to pay net
metered customers 19-20 cents per KWh, it would be more beneficial from the
perspective of the utility to pursue municipally owned solar development rather than
community solar which would take advantage of net metering incentives.50 Under
Vermont's current net metering laws, customers maintain the right to retain RECs or
turn them over to the BED. Customers typically do not turn the RECs over, which raises
questions about how RECs should be managed and where they can provide greatest
benefit.5 1 Future policy decisions affecting RECs, net metering and tax incentives will
play a major role in directing where new resources are sited, how they are operated,
and who benefits from their installation.
Operational & Technical Concerns
Solar PV projects on roofs of existing buildings present a variety of operational
concerns for building owners. A major concern voiced by facilities managers of buildings
owned by the City of Burlington has been roof maintenance. Once a solar system is
installed on a roof, maintenance of the roof becomes more difficult, and the logistics of
replacing a roof become more complicated. An ideal scenario for retrofit applications is
installing PV over a new or well-maintained roof that will not need major overhauls
during the lifecycle of the PV installation which is around 30 years.
A secondary concern is with the method of attachment. There are two primary
ways of installing roof mounted PV, the first involves mechanically fastening the system
to a building's roof structure by penetrating the roof membrane. Despite successful
installations with leak-free track records, this method adds risk from the perspective of
facility managers. At the scale of an individual PV installation, it is easy for these
concerns to overshadow the margin of return on the investment. A second method of
securing PV systems on roofs is by using ballasted racking, but this is only a viable
solution on flat to low slope roofs with sufficient structural capacity for the added weight.
Both methods of installation bring up issues of liability for roof maintenance and PV
system maintenance. These types of agreements can be complex and act as deterrents
for building owners as well as installation companies. Addressing these concerns will be
an important component of community outreach, in order to help overcome hesitation
about installing solar on a large number of roofs.
Collective Action & Project Scale
In 2009, Burlington voters approved a tax-exempt bond for improvements of the
city electrical system, including $4 million for renewable energy development. In 2013,
the city released an RFP for solar on approximately 30 municipal structures. Of these
potential sites, only the eight largest received proposals, and only the airport garage
installation was executed. According to city comments, only sites with the highest
potential ROI received bids, and of those that came close to development, operational,
aesthetic and financial concerns won out over renewable energy. These concerns either
eliminated sites entirely, or reduced the site area to a point where the economics only
broke-even, according to the city. The RFP for solar on municipal buildings, while
largely unsuccessful from an installations perspective, should be seen as an opportunity
to rethink how and where municipalities promote solar PV. This brings up barriers to
collective action. Although Burlington's municipal solar RFP was a form of collective
action, the economics were still focused on the scale of individual buildings. At the
building scale, the size of the array needs to be a certain proportion to the total square
footage of the building in order to pencil out economically. In the built environment, this
ratio makes solar unattractive for many multi-story buildings, where the ratio of roof area
to building area is relatively low. Another barrier to collective action in cities is the added
complication of rental properties-where building owners who don't pay electricity bills
see little incentive in installing rooftop solar or improving efficiency. Over 40% of BED's
residential customers live in rental properties, and 65% of their commercial customers
lease their space.
Despite these challenges, even if the success rate of installing solar on all of
Burlington's 10,000+ buildings was the same as the city's municipal solar effort (1 in
30), that would equate to over 333 installations city-wide. A city-wide campaign presents
numerous hurdles in terms communication, governance, economics and physical
planning. On the other hand, casting a wider net should reveal more opportunities,
engage more political and economic capacity, have the potential to make a bigger
impact and gain more public support. To be successful, such a campaign needs to
prepare innovations in existing operational, ownership and planning models; it needs to
engage a broad base of community members, and it needs to develop an actionable
plan that addresses the spatial, political, and economic potential of a city-wide initiative.
Building on the barriers and opportunities for solar in the built environment, the
following section investigates precedents in operational models for community solar,
public outreach and education campaigns focused on solar, as well as a variety of
municipal policy approaches for regulating and promoting solar development. This base
of information can be adapted in order to address specific concerns and opportunities in
Burlington.
Precedents
Community Solar Project Models
In 2011, the National Renewable Energy Lab (NREL) published a guide to
project development for community solar, and defines community solar as: a solarelectric system that, through a voluntary program, provides power and/or financial
benefit to, or is owned by, multiple community members. NREL cites an internal study
finding that only 22-27% of residential rooftop area is suitable for solar in the United
States, and acknowledges that community solar only makes up a portion of the total
solar market.5 3 The guide focuses on projects designed to increase access and reduce
up-front costs, achieve economies of scale, optimal project siting, increased public
understanding of PV, generation of local jobs, and opportunities for new models of
marketing, financing and service delivery. Before addressing community solar project
models, two other common mechanisms for deploying solar are discussed, Power
Purchase Agreements (PPAs) and Solar Services Agreements (SSAs). A PPA is an
agreement between a wholesale energy producer and a utility, where the utility
purchases power at an agreed upon rate for a specified time period. A SSA is an
agreement between the owner of a solar system and the owner of the site where the
system is located; the system owner designs, installs and maintains the system under a
contract with the system host. The following models for community solar build on the
basic components of PPAs and SSAs.
NREL point to three primary models for community solar: the utility sponsored
model, where the utility owns or operates a project that is open to voluntary ratepayer
participation, the special purpose entity (SPE) model where individual investors create a
business and develop a community solar project, and finally the non-profit model, where
donors contribute to a community solar project owned by a non-profit corporation. Each
model serves a different set of financial and needs, and can be applied in a variety of
contexts, not necessarily exclusive of one another.
In a utility sponsored model, participating ratepayers are awarded production
incentives, the value of energy and in some cases RECs, in exchange for either an
upfront or ongoing monthly payment, or credit on their electric bill which is proportional
to their contribution and the energy production of the project. The customer has no
ownership stake in the project, but rather buys rights to the benefits of the system.
While public utilities are unable to take advantage of tax credits, the ease of
participation in these models can sometimes offset those benefits through higher
enrollment and managerial efficiency.54
SPE models are designed take advantage of the significant benefits provided by
the federal investment tax credits, but in doing so bring a higher level of contractual
complexity to community solar. Most participants in community solar projects don't have
passive income, and therefore can't take advantage of the tax credits. Developers of
SPE models need to find key investors with passive income and large tax appetites,
such as building owners with large amounts of rental income. NREL describes three
financing structures for SPE models that attempt to maximize the benefits of the federal
tax incentives: self-financing, flip structures, and sale / leaseback. A self-financed model
is the simplest structure and grants ownership to the community of investors, however
its success hinges on securing an investor within the community with a large tax
appetite. In a flip structure, the community SPE would partner with a tax-motivated
investor to form a new SPE that would own and operate the project. This new SPE
would provide most of the initial equity, and would also receive up to 99% of the project
benefits for the first five years. After this investor recouped tax benefits and achieved an
agreed upon rate of return, the community SPE would then have the right to purchase
the project at fair market value. The sale / leaseback approach requires the community
SPE to host and or develop the project then sell it to a tax investor and lease it back
while continuing to operate and maintain the project. This option also includes the
option for the community SPE to purchase the project from the tax investor, after the tax
benefits have been monetized. Each of these models relies extensively on complex
legal, financial and tax regulations, and as such demand additional capital to pay for
consultants.
A non-profit model isn't able to provide electricity directly to donors who write off
their contributions as tax-deductible. However, there are precedents of non-profits
teaming up with third party for-profit entities that can install and own the system to take
advantage of investment tax credits. Although non-profits are not eligible for tax
deductions, they can qualify for other sources of funding from foundations that are
inaccessible to businesses. It is also important to note that contributions to a non-profit
are only tax deductible at whatever percentage the donor's tax bracket specifies, so the
potential benefit is much less than the investment tax credit. 56
Officials in Burlington's department of public works and BED have indicated that
there is some interest in community solar, but that there hasn't been a concerted effort
to analyze or implement it yet. In Burlington's RFP for municipal solar, several proposals
for community solar were submitted. The proposals were for the developers to finance
and install systems on space leased from the city, and to then sell the benefits of
individual panels to BED ratepayers. For the city, it was unclear what additional
advantage this model provided over other proposals for PPAs which distributed benefits
equally to all ratepayers. The city also expressed issues about what would happen if the
proposals were under-subscribed. Based on the NREL analysis of community solar
models, appears that for community solar to be effective, it needs to be implemented at
a certain scale, and engage investors with large tax appetites. Based on the limited
scale of the RFP for municipal solar in Burlington, it is unlikely that either of these
parameters for success were fully addressed.
In an effort to mitigate the complicating factors of community solar, the residents
of Portland, Oregon started a campaign with a local neighborhood organization called
Solarize Portland. The first solarize campaign in 2009 was wildly successful, and now
cities around the United States have implemented similar campaigns.
Solarize Campaigns
The first solarize campaign was started in southeast Portland, Oregon, and
eventually spread to the entire city. As the program grew, it drew the support of the U.S.
Department of Energy (DOE) Solar America Communities Program, the City of Portland
Bureau of Planning and Sustainability, Solar Oregon, and the Energy Trust of Oregon.57
Solarize published a guidebook in 2011 that outlines the basic components of a solarize
campaign, and provides statistics about the success of Solarize Portland. The basic
model is designed to overcome cost, complexity and customer inertia. To address cost
concerns, the campaign provided a summary of all state and federal incentives and
rebates, and used this as marketing material to generate project leads which in turn
drove contractor marketing costs down by as much as 35%. To reduce complexity a
neighborhood committee pre-selected a contractor through competitive bidding and
eliminated the number of choices for individual consumers. The typical sales cycle in
Portland at the time of the first campaign was 2 years from first inquiry to installation; by
introducing a limited time offer for group action the campaign made consumers feel
more comfortable collectively and reduced the cycle to 3-6 months.58 The first campaign
signed up 300 customers, installing solar on 130 homes to provide 130 kW of PV
capacity in the first 6 months, which created 18 full-time professional wage local jobs.
Between 2009 and 2011, Solarize Portland added over 1.7 MW of PV capacity on over
500 homes throughout Portland, creating 50 jobs and helping to spur market growth in
independent PV installations.59
The solarize guidebook emphasizes the importance of competitive contractor
selection, community-led outreach and education, and a limited-time offer as key factors
for the success of any solarize campaign. The guidebook outlines a process to guide a
neighborhood or city through a collective purchase program, and offers
recommendations for campaign partners. This begins with cultivating awareness
through grassroots communication efforts, and then education programs are offered
throughout potential neighborhoods to provide opportunities for community members to
ask questions and voice concerns. Following community outreach efforts, signup is
facilitated through an online system, and individual sites are assessed by the installation
contractor who provides estimates to each enrolled member. After the site assessment
potential customers decide whether or not to accept the contractors offer, and
contractors can offer added incentive by providing a discount if volume targets are met.
To engage the community in the initial phases of the process, the guidebook
recommends partnering with an established non-profit organization with a history of
providing benefits in the concerned areas. The guidebook also identifies the need for a
technical advisor to ensure quality and walk participants through technical hurdles; in
Portland the Oregon Energy Trust filled this role. A project organizer is also essential for
coordinating outreach, overseeing the project timeline and streamlining permitting, for
Solarize Portland the city government filled this role.
In 2010, the Vermont Public Research Interest Group (VPIRG) created a VPIRG
Energy subsidiary to start a similar group purchasing program. VPIRG used its existing
network of members to initiate education and outreach, running 10 campaigns in 5
Vermont communities which eventually lead to the installation of 60 solar PV projects
totaling 300 kW of capacity.60 VPIRG used a $0.25/watt lead-generation fee to recoup
its operational costs. In 2012 VPIRG Energy finished their campaigns and started a forprofit venture Suncommon, which provide homeowners with a solar lease for zero
money down. The fixed-rate lease payment is around the same as the homeowner's
current electricity bill, and operates under the premise that as electricity prices rise,
customers will see savings in their electric bills. Since 2011, 18 states have run 175
Solarize Campaigns, with Connecticut, Massachusetts, Oregon and Vermont leading in
total campaigns.
Solarize Campaigns
38
29
241
13 15 1
6
1
1
1
1
1
2
8
4
CO MD PA RI VA UT NY TX WI NH NC CA WA DC VT OR MA CT
Figure 11: Solarize Campaigns by State
Source: Solar Outreach, sponsored by: United States Department of Energy, SunShot Program, 2014.
Given the demonstrated commitment to renewable energy and solar PV on behalf of the
it makes sense
city of Burlington, and the potential benefits of community solar projects,
for Burlington to investigate the potential of a large-scale solar PV campaign. For the
can
city to assess the impacts a campaign, spatial analysis of the built environment
as part of a
provide basic parameters to guide targeted policy and community outreach
comprehensive planning vision.
Solar Zoning Models
Another way municipal governments have encouraged or accommodated solar
into zoning
projects is through zoning models. Arguments for incorporating solar rights
61
draw on the
emerged in the United States as early as the 1970s. These arguments
incorporation of the doctrine of ancient lights into common law. Under this doctrine, if an
individual had light or air coming into their window for a period of 20 years, a neighbor
62
could not block that light or air. In the 1970s the United States had no legal provisions
of a concern in the
guaranteeing property owners access to the sun; this became more
41
context of passive and active solar technology, and the energy crisis of the early 1970s.
A proposal for a model solar zoning ordinance developed in 1978, includes definitions
for solar collectors, and draws on the concepts of beneficial uses from water law to
protect but not guarantee solar rights. The ordinance also allows local governing bodies
to determine the amount of acceptable shading of neighboring lots. The ordinance
incorporates a position for a city forester to assess and enforce vegetative shading
violations, but it also includes variances when literal interpretations of the ordinance
would result in unnecessary hardship. Another key component of the proposed
ordinance is that it allows for the transferability of solar rights by either sale or gift.
Since the 1970s, solar ordinances have become more common, and cities
around the world have developed ordinances to suit their particular geography and
structure. As these ordinances become more common and accessible, cities borrow
and adapt existing ordinances to suit their own needs. Israel was an early adopter of
solar hot water technology (SHW), and started mandating these systems in the early
1980s.
In the 1990s, Berlin developed a solar mandate model which was unsuccessful in
Germany, but was eventually adopted by the city of Barcelona, Spain in
1999.63
The
Barcelona ordinance targeted homes, hotels and gyms, requiring that 60% of their hot
water be supplied by SHW. By 2004, 11 Spanish cities including Madrid had adopted
the ordinance, and in 2006, Spain made it a national law.6 4
China has also adopted national laws which require the adoption of SHW
systems. The laws require local government to develop policies geared toward
integrating SHW; they require real estate developers to make provisions for solar
energy, and they require residents of existing buildings to install SHW if deemed
feasible.65 In areas with high levels of insolation, China is requiring buildings that use
intensive amount of hot water, like schools and hospitals, to gradually incorporate SHW,
and for new construction to at least provide adequate space for future installations. 6
In the United States, the American Planning Association (APA) provides
extensive information on planning and zoning for solar energy. This information is
compiled in an essential information packet, and available for download on the APA
website; the packet contains over 100 municipal solar policies from municipalities
across the U.S. 67 The frequency and focus of these municipal solar policies shows
growth in solar policy over the last 15 years, as well as a shift toward more proactive
and even regulatory solar policy. The packet includes information on solar in
comprehensive plans, subarea plans, functional plans, permitting guides, solar
ordinances, easements, access/protection, orientation and siting, as well as mandatory
solar installation. The dates and focus areas of the sample policies indicate a major
increase in solar policy starting in 2008. The focus of these policies is primarily on the
definition and inclusion of systems in zoning ordinances, but in recent years these
policies have expanded to include definitions for multiple scale systems, solar ready
homes, and more-specific policies for streamlining permitting, optimizing siting and even
requiring solar systems. These policies range significantly in scope, but between 2012
and 2014 there is an increase in model solar ordinances that attempt to incorporate
multiple features of these policies. Figure 12 shows the frequency and type of policies
sampled by the APA from 1998 to 2014.
U.S. Solar Zoning Policies
30
25
20
0
12accessory
27
1998 1999 2000 2001 2002 2003 2D04 2005 2006 2M
MM
2M
2MO 201
mandatory systems (1)
subarea (3)
a easement / access permits (5)
a permitting guides (6)
* model ordinances (6)
1 multiple scale systems (6)
w solar ready homes (7)
a orientation and siting (8)
z functional (9)
a access protection (10)
a comprehensive (12)
systems (12)
2012 2013 2014
Figure 12: U.S. Solar Policies by Type and Date
Source: Sample from American Planning Association, Planning and Zoning for Solar Energy Packet, 2014.
As solar policy is becoming more progressive and common in the United States, there
are now ample policy-precedents for cities like Burlington to draw on, and to further
develop its own municipal ordinances in direct support of solar energy. While solar is
more frequently mentioned in comprehensive master plans, these plans typically only
state that renewable energy is a goal, and that solar is one way to reach that goal, there
is generally a lack of specificity as to the specifics of how exactly solar systems will be
incorporated in the comprehensive plans. Functional plans start to get more specific,
focusing on particular buildings and setting general capacity targets. Permitting policies
tend not to focus on the larger picture of municipal solar, but rather on facilitating
individual installations by providing definitions, and general guidelines on calculating
capacity, finding local installers and submitting the appropriate paperwork and fees.
Solar access and easements provide a model for property owners to develop solar
envelopes without causing hardship to their neighbors, this starts to address the social
and political complications that can arise with adjacent ownership and vegetative
44
MOMMMMMEMMMMMOMr- -
-w-
IIIIIII.Ix- -
---
shading. Solar access protections take these easements to the next level by developing
setbacks and regulations for the physical properties of structures as well as vegetation.
Policies focusing on orientation and siting focus primarily on new development,
and require that its layout maximizes solar exposure at the neighborhood scale as well
as the scale of individual buildings. It also regulates planting choices and even
vegetation management. Policies for solar ready homes address both new and existing
structures, by requiring all construction and significant renovation to at least provide a
roof layout for solar PV or SHW, and to provide plumbing and conduit for eventual
installation. This type of policy has been developed in Arizona, California, Florida,
Nevada and Virginia. Building on solar preparedness, in 2014, the city of Lancaster,
California, introduced a zoning ordinance requiring a minimum of 1.5 kW of solar PV for
all new single family homes. The ordinance allows this provision to be met through
either installing a system on the home itself, or through the documentation of a solar
purchase agreement. 8
Model ordinances attempt to synthesize the best practices of these various
plans, and provide general language that municipal government can adapt to their own
contexts and specific goals for solar. These ordinances tend to focus on the definitions
and regulation of projects that will be installed, and are generally more reactive than
proactive from a planning perspective. Out of the various solar policy types, solar ready
homes, mandatory systems, and site planning take on a more active role, but still focus
primarily on new development or at the scale of the individual building. All of these
efforts are useful and important, but there are opportunities for municipal government to
strengthen these efforts by incorporating spatial analysis of the built environment in
order to target these efforts at a larger scale.
The 2014 edition of Burlington's Comprehensive Development Ordinance (CDO)
is the closest the city comes to providing specific guidelines for solar development.
The CDO starts to address the spatial planning implications for renewable energy and
solar PV. It encourages site plans to maximize solar access with building positioning
and open space; it requires new structures and additions to minimize shading on
existing buildings or public spaces to maximize solar opportunities; and it encourages
rooftop solar. The CDO also provides variances for renewable energy resource
structures if they can't be built to regulations, and won't be detrimental to the public
welfare.
Given the context of more explicit and aggressive solar ordinances in other cities,
there is room to strengthen the specificity and support for solar in Burlington at the scale
of the building, the block and the entire city. At the scale of the building and block,
Burlington can draw on precedents from other municipalities, but at the scale of the built
environment, Burlington's municipal government will need to explore new territory in
renewable energy planning. To strengthen and focus solar policies and project models,
cities need to understand the potential capacity of their open spaces and built
environments. There are numerous methodologies used to project solar capacity, and
cities can choose among these depending on their available resources and expertise.
The key point however, is that by projecting the potential capacity through spatial
analysis, cities will be able to make more informed decisions about renewable energy
development and policy.
Projecting Capacity
Spatial Analysis of Solar Capacity
There are multiple scales of analysis for estimating the potential solar energy of
any particular site. The primary factor is the solar insolation which is determined by a
site's latitude and longitude. It is relatively easy to find NASA-produced maps for every
country in the world showing the relative insolation of particular regions, provinces or
states. For the United States, NREL provides 10km resolution maps showing insolation
for each state. Insolation is typically measured in kWh per square meter per day. The
average insulation for Anchorage, Alaska is around 3, while in Phoenix, Arizona the
average insolation is above 6.5. Vermont's average insolation is 4-4.5. Estimating
insolation within the built environment however, entails a more complex process which
must take into account building orientation, building height, roof pitch and shading. To
negotiate this complexity, researchers have developed a variety of methodologies to
accurately calculate the potential insolation for the built environment.
In 2013, NREL released a publication reviewing the various methods for
estimating rooftop suitability for PV, including a methodology developed by NREL. The
primary methods for estimating the technical potential of PV use constant values,
manual selection or GIS-based analysis. Each method has advantages and
disadvantages: the constant value method is quick and easily computes rooftop area,
but the generalized results don't take into account local rooftop characteristics and are
difficult to validate; manual selection methods are more detailed and allow assumptions
to be made based on regional building knowledge, but these methods are time-intensive
and difficult to replicate in other regions; GIS-based analysis is also detail-specific, it
can be easily replicated or even automated, but GIS analysis is very intensive in terms
of time and computer processing capacity.69 After reviewing the literature for each
method, the NREL study concludes that there is a wide degree of variation in
recommended slope, orientation, shading and size characteristics of roofs. Based on
these conclusions, the proposed NREL method makes the following assumptions: the
slope of the roof should be no greater than 60 degrees, the orientation should range
from east-south-west, the rooftop should be in sunlight for the minimum number of
hours to achieve 80% generation based on its region, and the available roof size should
be a minimum of 10 contiguous square meters. The specific methodology of the NREL
method employs LiDAR data and building footprints as inputs for a GIS model, and uses
hill shade, slope, and aspect calculation tools to estimate the unshaded roof space and
orientation available for PV. NREL used over 200 existing PV installations in New
Jersey, Colorado and California to validate the accuracy of their model and achieved
satisfactory results. NREL is currently working to validate and improve the accuracy of
their model using 120 cities across the United States. Their ultimate goal is to use
statistical methods to generalize the results of their model to other areas in the United
States and to provide a national database of total rooftop space for PV.
Pending the release of a comprehensive national database, organizations around
the country have undertaken efforts using similar methodologies, including Mapdwell,
and the Renewable Energy Atlas of Vermont. Both of these projects use an online
mapping platform to project the potential solar capacity of rooftops in a given city.
Mapdwell uses digital elevation data and methods analogous to NREL's approach, and
currently provides data for the cities of Boston, Cambridge and Wellfleet
Massachusetts, as well as Washington DC, Washington County, Oregon, and Vitacura,
Chile. The Renewable Energy Atlas of Vermont takes more of a hybrid approach that
incorporates constant-value regional data with GIS technology, and provides data for
300,000 sites in Vermont's E-9-1-1 database. Both online systems are equipped with
slider-bars that allow users to change the amount of PV installed to estimate cost
differentials, incentives, and payback periods. The systems also provide links to local
solar installers as well as state and municipal level resources for parties who wish to
initiate installations.
An Alternative, Targeted-Model
While these models succeed as educational tools for the general public and
motivated building owners, they don't explicitly target any particular portion of the built
environment, such as clusters of high-potential parcels. Municipalities don't employ
these tools as part of specific planning initiatives. For the most part, these broad tools
allow individuals to assess isolated instances of PV capacity, while ignoring the
potential for collective action afforded by community solar models and group purchasing
campaigns like Solarize. In light of this gap between technological capacity and the
development of specific planning visions, the following spatial analysis is geared toward
identifying specific zones within Burlington's built environment, in support of a targeted
plan for community solar.
This analysis synthesizes vital elements of existing methodologies for the rapid
targeting of high-capacity areas. The straightforward and efficient model for assessing
municipal solar capacity and targeting outreach efforts can be developed with basic GIS
software, land use data and public outreach efforts. The model incorporates flexibility for
increasing the spatial resolution of its data, and it can also be applied to other
municipalities. The primary function for the model is to identify areas with high solar
capacity and their associated stakeholders, and to organize this data in order to initiate
a public planning process.
Spatial Description of Burlington
Burlington is Vermont's most populous city, and the surrounding metropolitan
statistical area houses approximately one third of Vermont's total population. 70 The city
of Burlington's population is approximately 42,000 people, or 6.7% of Vermont's total
population. The municipal border of Burlington contains approximately 15.3 square
miles, of which 10.6 square miles is land area, and 4.7 square miles is the portion of
Lake Champlain designated as Burlington Bay. The land area of Burlington is a
crescent shape that opens to the southwest around Burlington Bay. The crescent shape
is approximately 6 miles long by 2 miles wide, and slopes gradually upwards to the east,
rising to 200 feet above the lake at the city's eastern border. The land area of Burlington
can be categorized by six primary functions as a percentage of total land area: open
space 31%, residential 30%, transportation and utility 17%, institutional 11%,
commercial 6%, and public 4%71
mp n
These six functions can be distilled into two primary categories: open space at
31% total land area (including various open space functions), and developed space at
69% total land area (including residential, transportation and utility, institutional,
commercial and public use parcels). The majority of open space is located just above
the midpoint of the crescent, and separates the developed space into two zones. The
northern zone is comprised primarily of lower-density residential parcels of .25 acres
and larger. The southern zone includes the majority of Burlington's commercial,
institutional and public structures, and has a higher residential density with smaller lot
sizes. This zone includes the downtown and university areas; it also houses 76% of
Burlington's total population, and contains 67% of the total buildings.72 Another
distinguishing characteristic is that the southern zone is built on a street grid that runs in
cardinal directions, while the street grid in the northern zone is rotated at a 450 angle.
These observations about Burlington's built environment help to set up a basic
framework for a more-detailed analysis of the potential area suitable for solar PV. The
next level of analysis addresses the specific geometries of the individual buildings
based on structure-type and solar orientation.
Spatial Analysis of Structures
In 2013, collaboration between Open Street Maps contributors and the City of
Burlington produced a public dataset that provides digital vector files for 10,066 building
footprints within Burlington. By overlaying aerial photography with the building footprints
and land use designations in GIS, it is possible to isolate individual buildings by land
use, and to determine the basic geometry of the building rooftops. Derived from this
data are the following characteristics about rooftops: Structures within commercial,
public, institutional, transit and utility land use designations have primarily flat roofs,
while structures within residential designations have primarily pitched roofs. The
designation of a flat versus pitched roof allows the building footprints to be divided into
two distinct groups.
Buildings with flat roofs are less-dependent on their solar orientation when it
comes to suitability for accepting solar panels. At Burlington's latitude, buildings with
pitched roofs need to be oriented as close to south as possible in order to achieve
maximum insolation. As one of the leading solar installers in Vermont, Suncommon
states that an orientation up to 150 east or west of true south has minimal impact on
73
efficiency, and merely favors morning or afternoon insolation. This is corroborated by
the United States Green Building Council's LEED rating system, which encourages
individual buildings as well as city blocks to be oriented within 150 of south, to optimize
passive and active solar opportunities.74 The data derived for roof pitch, building
orientation and land-use type is summarized in table 1 below:
Type
No. Buildings
GSF (Footprint)
ResIdentiall Total
3,089
4,066,62,5
Semi-Optimal: SE 30*-15*
Semi-Optimal: SW 30*-15
Optimal: SE 15*-00
305
320
1,896
401,568
437,446
2,450,776
Optimal: SW, 150-O0
Commercial Total
PubAic Total
Institutional Total
TransitIUtility Total
Suitable Buildings Total
Buildings, Total
% Suitable
568
472
76
349
131
4,117
101066
41%
776,835,
3,778,804
396,711
2,811,778
897,127
11,951,045
20,274,235
59%
Table 1
The table includes all primarily flat-roofed structures (commercial, public,
institutional, transit and utility), but only includes residential structures whose orientation
is within 300 of south. The residential structures are further subdivided into optimal and
semi-optimal categories based on orientations between 00-150 and 15*-30* respectively.
Residential structures with orientations greater than 30* are eliminated. This yields
52
4,177 potential structures for solar, which equates to 41% of Burlington's total buildings,
and 59% of the total area of building footprints.
Roof slope is not typically a delimiting factor for installing solar panels. For
instance, Suncommon can install their mounting systems on roofs with slopes from 100450, which encompasses the vast majority of vernacular roofs found in Burlington. For
flat roofs, a different mounting system is used that tilts panels at around 350, which
provides optimal insolation for both summer and winter at Burlington's latitude.75 What
roof slope does impact, is the total surface area of the roof, which increases as steeper
slopes lengthen the hypotenuse. For flat roofs, the roof area is typically a 1:1 ratio
relative to the building footprint, but for pitched roofs this ratio ranges from 1:1.11 for
6:12 pitches, to 1:1.30 for 10:12 pitches. A survey of the classical architectural styles
after which the majority of Burlington homes are modeled, suggests that slopes in
Burlington range from 6:12 to 12:12.76 Assuming an average roof slope of 8:12, allows
for the calculation of total roof area at a ratio of 1:1.20 relative to the average size of
residential building footprints. Residential roof areas must also be divided by half since
only one plane of the roof can face south. Table 2 shows the estimated total roof area
that is optimal for installing solar PV based on slope and orientation:
Type
Residential Total (Optimal)
Commercial Total
Public Total
Institutional Total
Trafl ltIUtity Total
Total:
GSF (Footprint)
3,227,61
3,778,804
396,711
2,811,778
897 127
11,951,045
Table 2
0
See maps on pages 73-75
GSF (Roof Area)
1.,936,567
3,778,804
396,711
2,811,778
897,127
10,324,395
These roof areas must be further reduced to account for obstructions from
building elements such as chimneys, dormers, and mechanical equipment. An analysis
of ten city blocks in Burlington, containing 346 residential structures showed that an
average of 33% of structures had physical obstructions reducing available roof area by
an average of 31%. The percentage of structures with obstructions is closer to 50% in
the southern zone of the city, where the building stock is older, and has a higher
frequency of dormers and more-complicated roof lines. The following table and keyedmap show the location and results for each of the 10 city blocks:
Block
1
Total
Buildings
16
Buildings w/
Obstructions
4
% Buildings w/
Obstructions
25%
% Roof
Obstructed
44%
2
3
4
5
6
49
23
51
48
33
10
4
26
27
18
20%
17%
51%
56%
55%
48%
29%
29%
32%
32%
7
27
15
56%
28%
8
23
4
17%
18%
9
59
8
14%
2W%
10
T ot:
17
346
4
120
24%
33%0,
24%
31%
Table 3
S)ee map on page 76
By using the more conservative average percentiles for the amount of roof area
obstructed (from blocks 4-7), the total residential roof area suitable for solar PV is
reduced from approximately 1.9 million sf to 1.5 million sf.
For the remaining structures, categorized as commercial, institutional, public,
utility or transportation, the primary concern for obstruction is mechanical equipment.
Given the structural similarities between these building types, this study uses a
composite constant value number derived by four separate studies of commercial
54
structures in the United States, designating 60%-65% of total roof area as suitable for
solar PV. 77 The following table summarizes the total available roof area after accounting
for obstructions from structural elements and mechanical equipment:
Type
Residential Total (Optimal)
Commercial Total
Public Tot l
Institutional Total
Transit/tit Total
Total:
GSF (Roof Area)
1,936,567
3,778,804
After Obstructions
1,500,000
2,456,223
396,711
257,82
2,811,778
897,127
9,820,987
1,827,656
583,133
6,624,873
Table 4
There are two additional factors for consideration of roof shading: vegetation and
neighboring buildings. Roof shading from neighboring buildings is not a big concern in
Burlington, as the building stock is relatively homogenous, and buildings of similar
heights are clustered together. The majority of non-residential structures in Burlington
are multi-story and their roofs exceed the height of nearby vegetation. They are also
located in zones with a low Normalized Difference Vegetation Index (NDVI), and fewer
established trees. In Burlington, shading from vegetation is more of an issue in for
residential structures.
The residential zones to the north and south of the downtown area have a higher
NDVI and more established trees. Trees can be trimmed or removed to eliminate
shading, but the decision to do so depends on the subjective valuation of personal
property. Vegetative shading is further complicated by the fact that it can be produced
by trees on neighboring parcels, and that over the 30-year life span of a solar
installation, the extent of shading can change significantly. Rather than assign
vegetative shading a constant reduction factor, this model provides data identifying
zones with high NDVIs, so that stakeholders can determine the appropriate course of
action, most-likely avoiding heavily shaded properties.
In summary, the total non-residential potential roof area, after accounting for
obstructions, is around 5.1 million sf. The total potential roof area for residential
structures, after accounting for orientation and slope is around 1.5 million sf, but some
of this is contingent on stakeholders' willingness to alter existing vegetation. The
primary implications of this data are that the greatest opportunity for solar PV based on
available roof area in Burlington, is in non-residential structures, with 64% of that square
footage accounted for by commercial and institutional structures. With the spatial extent
of potential area for solar PV identified, the next steps are to identify the various
stakeholders associated with these parcels, and to formulate a general planning
.
approach. 0 See map np-age
Spatial Analysis of Open Space
Despite the relatively large quantity of open space in Burlington, there are not
many instances where this space is likely to be suitable for ground mounted PV. The
primary factors limiting the suitability of Burlington's open space have to do with current
land uses that provide cultural and environmental value. The majority of Burlington's
large parcels of non-forested open space are either designated as wetland area, located
in floodplains, or used as agriculture. The remaining smaller parcels consist primarily of
wooded areas, parks, lake front property, cemeteries, and lawns, all of which provide
either cultural or physical obstacles for solar.
After excluding remaining open area based on size and an evaluation of their
cultural and environmental value to the city, only 10 potential sites remain for ground
mounted solar. These 10 sites comprise approximately 100 acres, or 4 million sf of
space, a significant amount as compared to the 6.6 million sf of potential roof area.
Despite the opportunity in terms of potential area, these 10 sites are likely to be more
difficult to develop than rooftops. This is due to the reality that ground mounted systems
are more visible than rooftop systems, more subject to vegetative shading, and they
also prevent sites from other potential uses during the 30-year lifespan typical of solar
installations.M See
n
page 7
One of the largest potential sites is the retired landfill owned by the city. This site
seemed like a prime candidate for a ground mounted system, and was included in the
city's efforts to develop solar on city-owned property in 2013, but encountered
community resistance due to its high visibility. 78 There are also risks with mounting
systems for landfills; pole mounted systems can penetrate the landfill membrane, and
ballasted systems can cause uneven settling which can also jeopardize the membrane.
Ground mounted systems can take a long time to go through permitting, as is evidenced
by the proposed South Forty solar project, which has been under development since
BED released a memorandum in October of 2013, stating it had reached a conceptual
power purchase agreement with the developer, and that the project would be beneficial
to BED customers. Given the demonstrated and potential barriers that are unique to
installing ground mounted PV in Burlington; it may make sense for the city to pursue
these systems separately from roof mounted systems.
Applications for Municipal Planning
The Role of the Municipal Government
Municipal government can play a significant leadership role in directing
development and organizing stakeholders, but those efforts need to be coordinated
around quantifiable resources. Open or developable land is an obvious resource for
many municipalities, and the focus of various municipal zoning and development
policies is directed at regulating how these resources are used. Existing buildings and
their rooftops are less commonly viewed as potential municipal resources, but in the
context of renewable energy development, municipalities need to expand the extent of
how they understand and define their resources. This is especially the case in land-poor
municipalities like Burlington, where building rooftops represent the greatest opportunity
for solar development. The mapping exercises undertaken in this project provide
Burlington with the necessary data to incorporate the renewable energy potential of the
built environment into a new definition of municipal resources. With this new definition,
Burlington's municipal government can function as a leader to identify and convene
stakeholders, develop supportive regulatory policies for solar in the built environment,
and adopt an appropriate project development model.
Identification of Stakeholders
Burlington's municipal leadership has the capacity and the responsibility to
convene stakeholders around common interests. By synthesizing this project's spatial
analysis with municipal property records, the leadership can engage in more precise
and informed outreach. The 2014 edition of the Burlington Assessor's Office Grand List
includes 11,147 unique parcel IDs, and their associated owners, addresses, areas, and
other data. By spatially joining the address fields of the Grand List to the state's E-9-1 -1
data points, all of the current owners of high-potential structures can be organized into a
targeted stakeholder database. Using this database, the municipal government can
initiate planning and outreach efforts to engage key stakeholders. The flexibility of the
spatial model allows for adjustment of parameters to expand or decrease the scope of
the stakeholder database.
While this database has the potential to be a powerful tool for increasing PV
generation in Burlington, its functionality is contingent on the capacity of the municipal
government to use it as part of a broader solar development plan. To orchestrate this
outreach and planning effort, key city departments already engaged in energy planning
can play important roles. These departments include the Department of Public Works,
the Planning Department, and the Burlington Electric Department. Together, these
departments can work to strengthen existing energy policies around specific regions of
the city, while incorporating community input from those who would be most affected.
Strengthening Policies for Solar
The primary tools by which municipalities govern the built environment are
through regulatory policies such as zoning ordinances, building codes, and incentives or
disincentives created through taxes and development rights. These tools have been
used in various combinations to address land use issues ranging from sprawl reduction
to urban land management. 79 The question for the city of Burlington is how these policy
tools might be applied to increase solar PV on existing structures, or at least prepare
these structures for future installations. There is no question of Burlington's commitment
to supporting local renewable energy projects, including solar PV. These goals are
stated multiple times in BED's Integrated Resource Plan, and in Burlington's Municipal
Development Plan, Climate Action Plan, and Comprehensive Development Ordinance
(CDO or Zoning Ordinance).
Of these plans, the CDO is the one that most explicitly engages design and
planning in the built environment, and it provides an existing regulatory framework for
the city to strengthen its spatial policies around solar. By drawing on best practices from
other solar ordinances, Burlington can incorporate approaches that incentivize and
prepare new development for solar. To address existing development, identification of
solar-optimal properties is a necessary first step. The identification of these properties
also lays the groundwork for a broader vision of solar development at the scale of the
city. An expanded section on solar development in Burlington's CDO could provide
better preparedness regulation and incentives at the scale of individual buildings, but
also aggregate these policies within a citywide database of solar-optimal properties.
A first step would be to use the database of solar-optimal properties to delineate
subgroups of properties based on building type and location within the city, and to
develop more focused regulation and incentives for these groupings. Even the act of
officially acknowledging these property groups in the CDO would be a success, and
help initiate targeted planning for solar development. By engaging stakeholders in these
target areas, the city can develop regulations and incentives to maximize solar potential
while addressing community concerns. Upon establishing regulatory parameters for
these property groupings or districts, the city can develop a customized project model
for ownership and financing that addresses concerns at multiple scales of development.
Developing a Project Model
Various models for developing large-scale solar projects involve different
ownership and benefit arrangements between private developers, public utilities, utility
customers and nonprofit organizations. In developing a model that works for Burlington,
the advantages and disadvantages of each model must be considered, and synthesized
with the specific opportunities and barriers for large-scale distributed solar in Burlington.
Following the spatial and economic analysis discussed in this thesis, Burlington's
commercial properties represent the majority of suitable rooftop area for solar;
commercial property owners are also more likely to have larger tax appetite, and thus
the ability to take advantage of state and federal tax incentives. Based on these
findings, it can be argued that Burlington's commercial real estate represents the
greatest opportunity for solar production, in terms of both potential area and economic
advantage. As such, it may be advantageous for Burlington to focus on developing a
project model specifically for commercial properties, and if this model is successful, it
can be expanded and adapted for institutional, public and residential properties.
In developing a project model for commercial properties, the city will need to
address the primary concerns that arose during its previous attempt at developing solar
on city-owned structures. The primary concerns that came up were economic payback,
the structural suitability of roofs, and maintenance. These concerns could be mitigated
by drawing on cost savings of bulk purchasing, streamlined contractor selection, and
guaranteed pricing strategies of the solarize model, as well as distributed ownership
and financing models.
Another approach to address the issue of payback is to decouple the installation
sites from the parties that own and benefit from the systems. In this way anyone who
wants to invest in and benefit from solar can take advantage of the most suitable
locations. This can also help mitigate concerns about the ratio of roof area to energy
consumption of specific buildings. For instance, if a large commercial property could
only recoup 5% of its annual energy consumption from an installation on its roof, it may
not be interested in the investment. However, if three residential property owners could
recoup 75% of their energy consumption from that same commercial roof (but were not
able to install solar on their own roofs), suddenly the installation has more perceived
value. Depending on the property owner, roof area could be leased, or donated to
interested parties, or incorporated into municipal regulations and incentives for rooftop
solar.
Leveraging RECs for New Capacity Planning
By synthesizing spatial analysis, policy, and innovative project models, the city of
Burlington can take steps toward developing new renewable energy within the municipal
borders. This will not only count towards overall renewable energy usage, but it has the
potential to reduce capacity obligation, provide local jobs, and further establish
Burlington as a leading proponent of sustainability. To successfully integrate all of these
components into an innovative strategy for solar development, the city will need to
invest significant resources in outreach, research and project management. While there
are numerous ways for cities to finance research and planning initiatives, Burlington
may be able to leverage its existing renewable resources to develop new ones.
As discussed previously, BED currently sells its Class I RECs to stabilize rates,
and then purchases less expensive Class 11 RECs to reclaim renewability. Since
Vermont's RPS will not be mandatory until 2017, BED may be able to temporarily
channel some of the revenue it receives from RECs to fund research and planning for
new renewables. In this way the money would still be used in support of renewability,
but in a different way. Depending on the amount of RECs used for this purpose,
Burlington's claim to renewability might drop in the short-term, but would eventually
return to 100%. Using revenue from RECs sold on the regional market to help finance
local renewable energy starts to create a positive feedback loop between existing
renewable assets and new ones. Once local renewables are developed the RECs they
produce can then feed back into the market to incrementally produce economic and
environmental benefits at both local and regional scales. For Burlington, the opportunity
for leveraging RECs is time sensitive, and would provide the maximum impact if
implemented before state and federal ITCs expire at the end of 2016, and before
Vermont's RPS becomes Mandatory in 2017.
By acting soon and assuming a leadership role, the city can leverage more
financial resources toward engaging stakeholders in developing policies and project
models for high-potential solar zones. If this approach succeeds at improving renewable
energy planning in Burlington, it holds the potential to serve as a model for other
communities and utility companies interested in developing local renewable energy.
Conclusions
The preliminary research presented in this thesis establishes a trend toward
urban sustainability and renewable energy, as one of many responses to mitigating the
impact of humans on the environment. It also juxtaposes the current deficit of current
global capacity in renewable energy, with the rapid growth of new wind and solar
capacity in recent years, as an opportunity for municipal government to incorporate
renewable energy production into the built environment.
The primary research undertaken in this thesis addresses the potential for
strengthening the role of municipal government in renewable energy planning,
especially for solar PV. The thesis focuses on the city of Burlington, Vermont, as case
study for existing leadership in the transition to renewable energy. It investigates the
contributing factors to Burlington's success, and also identifies opportunities for
Burlington to improve its already impressive track record of supporting renewable
energy.
This thesis advocates for synthesizing spatial analysis and regulatory policies
within the built environment, so that municipal governments can support renewable
energy development in more calculated and spatially deterministic ways. In order for
this synthesis to occur, municipalities need to reframe the way they define resources by
incorporating the built environment into these definitions. Following the synthesis of
these factors, municipal government must take leadership in convening stakeholders to
realize the opportunities for producing renewable energy in the built environment.
Findings & Products
This thesis finds that Burlington's ability to claim renewability for the electricity it
uses, benefits from the value of RECs created by the adoption of renewable portfolio
standards in neighboring New England states. In this sense, there is reciprocity
between the notion of self-sufficiency provided by local renewable energy production,
and the interconnection of electricity transmission and the market for RECs at the
regional scale. This is significant in the potential for municipalities to leverage the
regional value of renewable energy, to develop new capacity at a local level, which in
turn provides regional environmental benefits, while also-in the case of solarreducing peak demand. As renewable portfolio standards become more stringent in
New England, the demand for new renewable energy capacity will increase, forcing
municipalities and utility companies to find ways of importing and producing renewable
energy.
To promote new sources of renewable energy in Burlington, this thesis provides
a GIS model incorporating environmental, structural and demographic data that
identifies and categorizes individual properties and structures based on their potential
for generating power through solar PV technology. The GIS model is paired with a
selection of precedents in solar project development structures, solarize campaigns,
and municipal solar zoning policies. These materials are presented to the city of
Burlington as a collection of base materials, intended to instigate a conversation about
how regulatory policy can incorporate quantitative spatial analysis to prepare the built
environment for future development of renewable energy.
65
Implications
The findings and products of this thesis carry theoretical, technical and
practicable implications for the future role of municipal government in renewable energy
development. Conceptually, municipal government needs to reevaluate the existing built
environment as a framework for the installation of new renewable energy capacity,
especially solar PV. This will necessitate the adaptation of existing understandings and
institutional arrangements around the use of private property for a public benefit (i.e.
roofs and renewables). Cities also need to develop strategies for balancing the costs
and benefits of local energy production within the context of regional transmission,
capacity obligation and demand for renewable energy.
From a technical perspective, the tools required for formulating more specific
spatial models of renewable capacity, for developing community solar project models,
and for legislating targeted renewable energy policies in the built environment, already
exist. The challenge is in the capacity of municipal government to synthesize these tools
and opportunities, and to assume a leadership role in their practical application.
The practicable implications of this thesis rest in the future incorporation and
continuation of this research by the city of Burlington. At a minimum, this research
provides a spatial and political framework for Burlington to identify specific zones within
the municipality as having high or low solar energy potential. At a maximum, the city of
Burlington will succeed in strengthening its support for renewable energy, and inspire
other cities to follow suit.
At a disciplinary level, the approach to renewable energy planning outlined in this
thesis argues for a shift in the dynamic between cities and energy. It seeks to add value
to urban areas by adapting them produce energy, in order to mitigate their role as the
world's primary drivers of energy consumption. Addressing this issue in the existing built
environment confronts the social, cultural, economic and political centers of civilization
as drivers of change, and as examples for future urbanization.
Limitations & Further Research
The implications around the opportunities and barriers for strengthening the role
of municipal government in renewable energy development, address a multitude of
complex economic, political and spatial issues. As such there is ample room for future
research on each of these issues. It is the intent of this this thesis, to provide the city of
Burlington with the digital files for the spatial analysis conducted herein, so they may be
used as base documentation for further research, such as:
*
A deeper analysis of community solar financing and ownership models through
case studies, and the investigation of how they can be specifically adapted to
provide the most benefit for the city of Burlington.
" Further calibration of the GIS model provided, to account for the latest changes
in Burlington's built environment, and to incorporate more local knowledge on the
suitability of specific areas.
" A comprehensive economic analysis of the potential impacts of a large-scale
community solar project on Burlington's net-metering program, peak load, and
capacity obligation to ISO-NE.
" Developing a series of solutions to address concerns about the structural
integrity of existing roof area, its durability and maintenance issues. These
solutions should be both design and finance oriented in order to prepare the
existing roof-scape to successfully receive PV.
*
Engaging community members from the outset, in order to identify questions and
concerns, develop a project vision, and build political support for incorporating
renewable energy in Burlington's built environment.
The research and potential applications outlined here are not intended to provide
a comprehensive planning approach for renewable energy in the built environment.
These approaches must be developed by their specific communities and municipal
leadership. The case studies of project development and policy examined here are not
exhaustive, and the spatial analysis performed can be refined to more accurately
identify high potential areas. With these limitations in mind, the findings presented in this
thesis provide a resource base for the city of Burlington to begin a conversation around
how it will prepare its built environment to accommodate renewable energy in the future.
Reference Maps and Diagrams: Pages 69-78
t~)
Supply Resources for 2016
40.2%
10.7%
9.5%
8.2%
7.6%
7.0%
3.8%
2.0%
1.6%
OMes
200
100
300
600
500
400
so mm Minimum Distance----------------------
-----------------------------------
Maximum Distance
i7
Biomass
Wind
Solar
Mixed Renewables
0Hydro
ISO-NE
Capacity Obligation
85-88MW
Supply Resources
+I- 380,O00MWh /year
Burlington's energyshed for electricity
69
Supply Resources for 2016
Vermont
70%
266,000 MWh
McNeil Biomass
Vermont Wind
Winooski One
GMC Wind
BED Solar
VEPPI
Standard Offer
Burlingtc n
100%
>382,000 MWh
Maine
18%
72,000 MWh
Nextera Hydro
Hancock Wind
Quebec
ffxiu
8%
30,000 MWh
Inio
Hydro Quebec
New York
4%
14,000 MWh
NYPA Hydro
70
Existing Solar PV Sites*
Roof-Mount PV Instalaton
Grund-Mount PVSl Boundary
Pending Ground-Mount PV St Boundary
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Grid Orientation & Open Space
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72
Building Footprints
Land Use
Residential
3,089 Potential PV Buildings
1,316 Average Square Feet
4,546,624 Gross Square Feet
C'
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Commercial
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472 Potential PV Buildings
8,006 Average Square Feet
3,778,804 Gross Square Feet
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Institutional /Community
349 Potential PV Buildings
8,057 Average Square Feet
2,811,778 Gross Square Feet
73
Building Footprints
Land Use
(L
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Transit / Utility
131 Potential PV Buildings
6,848 Average Square Feet
897,127 Gross Square Feet
Public /Assembly
76 Potential PV Buildings
5,220 Average Square Feet
396,711 Gross Square Feet
74
\
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78
0
Methodology of Spatial Analysis:
Synthetic Approach
Drawing on the NREL's 2013 publication that reviews various methods for
estimating rooftop suitability for PV, this thesis synthesized components of each method
according to requirements for expediency, practicality and data availability. To reiterate
NREL's findings, there are three primary methods for conducting a PV-capacity analysis
in urban areas: constant values, manual selection, and GIS-based analysis. Each of
method has advantages and disadvantages relative to accuracy and required inputs of
time. The goal for synthesizing these methods is to arrive at an approach that provides
accurate results in a short period of time. The primary components of the analysis
addressed the potential structures and open space available for PV.
Spatial Analysis of Structures
The analysis of structures employs GIS-based techniques and analytical
processes, manual selection of a sample, and derives context specific constant values
to determine key suitability factors. The key datasets used were building footprints, land
use, and infrared aerial photography. The primary factors for suitability include roof
slope, orientation and shading.
To determine roof slope, first individual building footprints were joined to parcels
based on land use, under the assumption that the vast majority of residential parcels in
Burlington have pitched roofs, while structures in other land use designations have flat
roofs. This assumption was then verified through visual inspection of recent aerial
photography. This broke buildings into two primary groups based on roof type, pitched
and flat.
7;
q
Orientation was only a concern for pitched roofs. To determine orientation of
pitch, a constant value assumption can be made of traditional residential architecture
typical of Burlington. This assumption is that the most efficient and common way to build
pitched roofs is to minimize the span of rafters, and to orient the ridgeline parallel to the
longest dimension of the structure. Under this assumption GIS tools can calculate the
orientation of each structure, and they can be grouped according to optimal and semioptimal deviations from south.
As discussed in the general spatial analysis, the actual pitch of roofs is not
generally a deterrent for the installation of PV as companies can accommodate a wide
range of pitches. The most significant impact of pitch is actually on roof area. To
determine this, an average roof pitch is assumed based on manual selection methods
that draw on common architectural pitches for residential buildings found in Burlington;
this is verified through visual inspection pitches in street view. After determining the
average pitch, simple algebra (the Pythagorean Theorem, averages and area
calculations) allows this impact on area to be calculated based on average residential
building size.
More advanced GIS techniques use LiDAR data to estimate roof pitch, which
provides a high level of accuracy, but is also very intensive in terms of processing and
time. LiDAR is more effective in identifying structural shading elements and building
height, but again involves high levels of input, and methods using LiDAR for these
purposes still recommend that the structures be inspected by a verified solar contractor
prior to installation. As an alternative to LiDAR, this analysis employed manual selection
methods and took a sample of over 300 structures in 10 residential blocks throughout
8 C'
the city, and calculated the average structural shading for the sample size, and used
that average to make a general assumption for all residential structures.
LiDAR is perhaps most effective in determining Building height, especially in
urban areas with no municipal records of height, and high levels of variation in height.
Burlington does not have building height data, but based on manual selection and
verification of aerial photography, the built environment is generally homogenous in
terms of height, with taller commercial buildings clustered away from lower residential
buildings. These observations rule out building shading from other buildings as a major
factor in Burlington, but like LiDAR methods, it is still important for individual structures
to be assessed by certified solar vendors prior to installation.
Spatial Analysis of Vegetative Shading
Vegetative shading can also be calculated using LiDAR data and GIS software to
determine the height and density of vegetation. However it is also possible to make
more general observations using color infrared aerial photography and NVDI processing
to identify areas with high concentrations of vegetation and potential shading problems.
Due to the complex nature of managing vegetation in a shared urban environment,
these issues need to examined by city arborists and addressed with land owners, both
which are beyond the purview of this analysis.
Spatial Analysis of Open Space
Open space suitability was determined by comparing land use data with aerial
photography to identify non-wooded open areas. These areas were then reduced based
on ecological and cultural factors associated with existing land use, as well as an
evaluation of potential community reactions to highly-visible ground mounted arrays. In
Burlington's case, installing PV on open areas is less of a technical planning issue and
more of a cultural one, which limits the ability of GIS software to develop accurate
suitability without community input.
Stakeholder Identification
The final and critical component of this spatial analysis involves identifying the
property owners of high-potential parcels or structures. This is done by joining available
property records from the Burlington Assessor's office to the states E-9-1-1 database of
addresses, and joining these with building footprints and parcels identified as optimal.
This synthesis takes the first step in developing a potential outreach strategy.
82
Notes
1The Intergovernmental Panel on Climate Change, Climate Change 2014: Mitigation of Climate
Change (New York: Cambridge University Press, 2014) 929.
2
The Intergovernmental Panel on Climate Change, Climate Change 2014: Mitigation of Climate
Change (New York: Cambridge University Press, 2014) 958.
3 The
Intergovernmental Panel on Climate Change, Climate Change 2014: Mitigation of Climate
Change (New York: Cambridge University Press, 2014) 675.
4 Dennis
Meadows et al, The Limits to Growth (New York: Universe Books, 1972) 88-128. ; Peter
Droege ed., Urban Energy Transition from Fossil Fuels to Renewable Power (Amsterdam:
Elsevier, 2008) 1-3. ; Paulo Ferrao and John Fernandez, Sustainable Urban Metabolism (Cambridge: MIT
Press, 2013) 5-7, 115-117.
5
G.H. Brundtland, and World Commission on Environment and Development. Our Common Future:
Report of the World Commission on Environment and Development (Oxford University, 1987) 3-27.;
Patrick Geddes, Cities in Evolution (London: Williams & Norgate, 1915) 60.
6
Paulo Ferrao and John Fernandez, Sustainable Urban Metabolism (Cambridge: MIT Press, 2013) 53.
7
Renewable Energy Policy Network for the
2 1't
Century, 2014. Renewables 2014: Global Status
2 1 't
Century, 2014. Renewables 2014: Global Status
Report (Paris: REN21 Secretariat, 2014). 21.
8 Renewable
Energy Policy Network for the
Report (Paris: REN21 Secretariat, 2014). 3.
9 Renewable
Energy Policy Network for the 2 1st Century, 2014. Renewables 2014: Global Status
Report (Paris: REN21 Secretariat, 2014). 14.
10
Renewable Energy Policy Network for the 2 1st Century, 2014. Renewables 2014: Global Status
Report (Paris: REN21 Secretariat, 2014). 14.
"Renewable Energy Policy Network for the 21st Century, 2014. Renewables 2014: Global Status
Report (Paris: REN21 Secretariat, 2014). 26.
12
Renewable Energy Policy Network for the
Report (Paris: REN21 Secretariat, 2014). 26
2 1st
Century, 2014. Renewables 2014: Global Status
13
Renewable Energy Policy Network for the
2 1't
Century, 2014. Renewables 2014: Global Status
Report (Paris: REN21 Secretariat, 2014). 49 & 59.
14
International Monetary Fund, Energy Subsidy Reform: Lessons and Implications. January 28t,
2013: 1-9.
15
International Monetary Fund, Energy Subsidy Reform: Lessons and Implications. January 28t,
2013: 5.
16
Renewable Energy Policy Network for the
2 1st
Century, 2014. Renewables 2014: Global Status
Report (Paris: REN21 Secretariat, 2014). 103.
17
U.S Energy Information Administration: International Enermy Statistics 2008-2013, 1, May. 2015
<http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=44&pid=44&aid=2>
18
Geoff Keith et al, Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as
Usual. November
19
,th2011: 8.
16
,th2011: 8.
Geoff Keith et al, Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as
Usual. November
23
16
Geoff Keith et al, Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as
Usual. November
22
2011: 6.
1 6th
Geoff Keith et al, Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as
Usual. November
21
2011: 6.
Geoff Keith et al, Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as
Usual. November
20
1 6 th,
16 t,
2011: 22.
Database of State Incentives for Renewables and Efficiency: 1, May. 2015 <http://ncsolarcen-
prod.s3.amazonaws.com/wp-content/uploads/2015/04/Net-Meterinq-Policies.pdf>
24
Database of State Incentives for Renewables and Efficiency: 1, May. 2015
<http://www.dsireusa.org/>
25
United States Department of Energy, Energy Efficiency & Renewable Energy Network, Green Power
Markets: 1 May. 2015 <http://apps3.eere.ener-y.qov/qreenpower/markets/certificates.shtml?paqe=5>
26
Galen Barbose et al, Tracking the Sun VII: An Historical Summary of the Installed Price of
Photovoltaics in the United States from 1998 to 2013, September 2014. 1-66.
84
27
G.R. Timilsina et al. "Solar Energy: Markets, Economics and Policies" Renewable and Sustainable
Energy Reviews 16 2 October. 2011: 449-465
28
U.S Energy Information Administration: International Energy Statistics 2008-2013, 1, May. 2015
<http://www.eia.gov/cfapps/ipdbproject/lEDndex3.cfm?tid=44&pid=44&aid=2>
29
U.S Energy Information Administration: Vermont State Profile and Energy Estimates 2015, 1, May.
2015 <http://www.eia.gov/state/?sid=VT>
30
Galen Barbose et al, Tracking the Sun VII: An Historicial Summary of the Installed Price of
Photovoltaics in the United States from 1998 to 2013, September 2014. 1-66.
31
Solar Source Residential Payback, 2012. 1 May 2015 < http://www.solarsourcene.com/residential-
payback.html>
32
Vermont Department of Public Service, Comprehensive Energy Plan 2011: 23.
3
Vermont Department of Public Service, Comprehensive Energy Plan 2011: 162.
34 Vermont Department of Public Service, Comprehensive Energy Plan 2011: 83.
3
The Burlington City Council and Planning Commission, Burlington's Municipal Development Plan,
2014:124-132.
36
Jennifer Green and Sandrine Thibault et al, Burlington Vermont Climate Action Plan, 2011: 1-25
37
Ever-Green Energy, Burlington District Energy Study, 2014: 60.
38
City of Burlington Vermont Department of Planning and Zoning, Comprehensive Development
Ordinance, 2014: 14.
39 Burlington Electric Department, Our Integrated Resource Plan, 2012: 9.
40
Burlington Electric Department, Our Integrated Resource Plan, 2012: 81.
41
Burlington Electric Department, Rule 5.2000 Resource Report January 2015 - January 2019,
3 0
th
January, 2015: 7-10.
42
Burlington Electric Department, Our Integrated Resource Plan, 2012: 82-86.
43
State of Vermont Legislature, An act relating to the Vermont energy act of 2012, 1 May 2015
<http://www.leg.state.vt.us/docs/2012/Acts/ACT170.pdf>
"Burlington
Electric Department, Rule 5.2000 Resource Report January 2015 - January 2019,
January, 2015: 5.
30 h
45 Vermont
Department of Public Service, Comprehensive Energy Plan 2011: 18-27.
46Due to Municipal Government's tax exempt status, cities often need to partner with private or
commercial developers who have a large tax appetite in order to take advantage of ITCs. BED did this
with its airport solar project and development company Encore Redevelopment.
47
Bruce Katz et al, "Miracle Mets: our fifty states matter a lot less than our 100 largest metro areas"
Democracy Journal Spring. 2009: 22-35
48
Elizabeth White, Renewable EnerZ
Cutting Green Tape While Improvin
Ecological
Outcomes for Renewable Energy Proiects MA Thesis. University of Vermont, 2014. 22-24.
49
Phone Interview with James Gibbons, Director of Resource Planning at the Burlington Electric
Department, 24th February, 2015.
5
Phone Interview with James Gibbons, Director of Resource Planning at the Burlington Electric
Department, 24th February, 2015.
51
Phone Interview with James Gibbons, Director of Resource Planning at the Burlington Electric
Department,
2 4th
February, 2015.
52
Burlington Electric Department, Our Integrated Resource Plan, 2012: 15.
5
National Renewable Energy Lab, J Melius et al, Estimating Rooftop Suitability for PV: A review of
Methods, Patents, and Validation Techniques, December 2013: 8.
54Jason Coughlin et al, A Guide to Community Solar: Utility, Private and Non-Profit Proiect
Development, November 2010: 7.
5, Jason Coughlin et al, A Guide to Community Solar: Utility, Private and Non-Profit Proiect
Development, November 2010: 12-19.
5 Jason Coughlin et al, A Guide to Community Solar: Utility, Private and Non-Profit Proiect
Development, November 2010: 19-21.
57
Irvine et al, The Solarize Guidebook: A community Guide to Collective Purchasing of Residential PV
Systems, February 2011: 3-4.
58
Irvine et al, The Solarize Guidebook: A community Guide to Collective Purchasing of Residential PV
Systems, February 2011: 5-6.
86
59 Irvine et al, The Solarize Guidebook: A community Guide to Collective Purchasing of Residential PV
Systems, February 2011: 5-6.
6
Irvine et al, The Solarize Guidebook: A community Guide to Collective Purchasing of Residential PV
Systems, February 2011: 15.
61
Melvin M. Eisenstadt et al, "A Proposed Solar Zoning Ordinance," Journal of Urban
and
Contemporary Law Vol. 15 Urban Law Annual. 1978: 211-215.
62
Melvin M. Eisenstadt et al, "A Proposed Solar Zoning Ordinance," Journal of Urban
and
Contemporary Law Vol. 15 Urban Law Annual. 1978: 211.
6
Muyiwa Adaramola, Solar Energy: Application, Economics, and Public Perception, (Boca Raton:
CRC, 2014) 200-201.
6
Muyiwa Adaramola, Solar Energy: Application, Economics, and Public Perception, (Boca Raton:
CRC, 2014) 200-201.
65
Muyiwa Adaramola, Solar Energy: Application, Economics, and Public Perception, (Boca
Raton:
CRC, 2014) 200-201.
66
Muyiwa Adaramola, Solar Energy: Application, Economics, and Public Perception, (Boca Raton:
CRC, 2014) 200-201.
67
American Planning Association, Essential Information Packet: Planning and Zoning for
Solar
Energy, 2014, 1 May 2015 <https://www.planning.org/pas/infopackets/open/eip30.htm>
6
Lancaster (California), City of. 2014. Code of Ordinances. Title 17, Zoning; Chapter 17.08,
Residential Zones; Article 11, Non-Urban, Urban, Medium and High Density Residential Zones; Section
17.08.060, Development Regulations by Building Types. Also, Article V, Solar, Wind, and Alternative
Energy Uses; Section 17.08.305, Implementation of Solar Energy Systems.
69
National Renewable Energy Lab, J Melius et al, Estimating Rooftop Suitability for PV: A review
of
Methods, Patents, and Validation Techniques, December 2013: 14-18.
70
Annual Estimates of the Resident Population: April 1, 2010 to July 1, 2014 Source: U.S.
Census
Bureau, Population Division. 1 May 2015
<http://factfinder.census.gov/faces/tableservices/sf/pages/productview.xhtml?src=bkmk>
71
Chittenden County Regional Planning Commission: November 2008, 1 May 2015
87
<http://maps.vcgi.org/gisdata/metadata/DemoCensusBLCK201 0.txt?>
7
Suncommon, Building A House with Solar in Vermont,
2 6th
July. 2012, 1 May 2015
<http://suncommon.com/building-a-house-with-solar/>
4
United States Green Building Council, Solar Orientation, 1 May 2015
<http://www.usgbc.org/credits/ea51>
75
Suncommon, Building A House with Solar in Vermont,
2 6th
July. 2012, 1 May 2015
<http://suncommon.com/building-a-house-with-solar/>
76
Urban Design Associates, Institute of Classical Architecture and Classical America, A Pattern Book
for Neighborly Houses: Architectural Styles, 2007: 1-18.
7
National Renewable Energy Lab, J Melius et al, Estimating Rooftop Suitability for PV: A review of
Methods, Patents, and Validation Techniques, December 2013: 8.
78
Phone Interview with Martha Keenan, Capital Improvement Program Manager, Department of Public
Works, City of Burlington, Vermont, February 18, 2015.
791Heather Campbell and Elizabeth Corley, Urban Environmental Policy Analysis (Armonk: M.E.
Sharpe, 2012) 208.