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Advanced Metering and Energy Information Systems
Grant 83378201
Report – July 3, 2009
Prepared for:
US Environmental Protection Agency
Karen Butler
1200 Pennsylvania Avenue NW
MS 6202J
Washington DC 20460
Advanced Metering and Energy Information Systems
EXECUTIVE SUMMARY .......................................................................................................................... 1
1
INTRODUCTION............................................................................................................................... 5
1.1
ADVANCED METERING AND ENERGY INFORMATION SYSTEMS .................................................... 5
1.2
OWNERSHIP STRUCTURE .............................................................................................................. 6
1.2.1
Utility Installed Advanced Meters vs. Owner Installed Advanced Metering .......................... 6
1.3
WHAT IS THE STATUS OF OWNER-INSTALLED EIS TECHNOLOGY? ............................................... 7
2
ENERGY INFORMATION SYSTEM COMPONENTS ................................................................ 8
2.1
METERING TECHNOLOGY ............................................................................................................. 9
2.1.1
Electric Meters ....................................................................................................................... 9
2.1.2
Natural Gas Meters ................................................................................................................ 9
2.1.3
Additional Meters and Sensors ..............................................................................................10
2.2
UTILITY METERS: UPGRADES AND ADVANCED METERING INFRASTRUCTURE............................11
2.2.1
Meter Dial Reader .................................................................................................................11
2.2.2
Pulse Output Upgrade ...........................................................................................................11
2.2.3
Utility AMI and AMR Meters: ...............................................................................................11
2.3
DATA ACQUISITION, COMMUNICATION, AND STORAGE ..............................................................13
2.3.1
Data Acquisition System ........................................................................................................13
2.3.2
Building Automation Systems, Integrated Platforms, and Middleware .................................13
2.3.3
Gateway and Communications Service .................................................................................14
2.3.4
Database and Data Storage...................................................................................................15
2.4
SOFTWARE TOOLS .......................................................................................................................16
2.4.1
Basic Software Tool Features ................................................................................................17
2.4.2
Intermediate Software Tool Features ....................................................................................17
2.4.3
Advanced Software Tool Features .........................................................................................17
3
COSTS FOR BASIC EIS TECHNOLOGY.....................................................................................18
4
DATA USAGE ANALYSIS METHODS .........................................................................................19
4.1
PORTFOLIO ENERGY TRACKING ..................................................................................................19
4.2
WHOLE BUILDING ENERGY BENCHMARKING AND BASELINING .................................................19
4.2.1
Temperature Normalization and Temperature Independent Analysis ...................................20
4.2.2
Additional Normalization, Energy Informatics and Energy Signatures ................................21
4.3
TIME SERIES VISUALIZATION TOOLS ..........................................................................................21
4.4
KEY PERFORMANCE INDICATORS ................................................................................................22
5
AREAS OF EIS UTILIZATION AND RESEARCH IN COMMERCIAL BUILDINGS ...........23
5.1
LARGE COMMERCIAL BUILDINGS ...............................................................................................23
5.2
CHAIN COMMERCIAL BUILDINGS ................................................................................................24
5.3
CAMPUSES AND GOVERNMENT FACILITIES .................................................................................24
6
ADVANCED METERING AND EIS PENETRATION ................................................................25
6.1
DRIVERS FOR INCREASED ADVANCED METERING AND EIS INSTALLATION ................................25
6.2
IMPEDIMENTS TO INCREASED ADVANCED METERING AND EIS INSTALLATION ..........................26
7
CONCLUSIONS AND RECOMMENDATIONS ...........................................................................27
REFERENCES..............................................................................................................................................28
INTERVIEWS ..............................................................................................................................................29
APPENDIX A ADVANCED METERING, EIS, AND SERVICE VENDORS .....................................30
Basic Owner-Installed EIS Vendors.....................................................................................................30
Additional Advanced Metering Vendors ..............................................................................................30
Integrated Platform (Middleware) Vendors.........................................................................................30
Third-Party Software Tools .................................................................................................................30
Energy Monitoring Service Providers: ................................................................................................31
APPENDIX B GLOSSARY .......................................................................................................................32
-i-
Advanced Metering and Energy Information Systems
Executive Summary
This paper is designed to help regulators, program managers and other interested parties
understand the new trends and technologies available in advanced metering as used in energy
information systems (EIS) in North America. An “advanced meter” is commonly considered an
energy meter that provides short interval measurements and can be read remotely. The term
“smart meter” is also used but generally refers to meters with the capability to send and receive
messages regarding pricing, along with other sophisticated utility functions. EIS refers to a
feedback system where advanced meters, remote database storage and software tools are
employed to monitor and maintain energy performance in a building.
The EIS collects energy performance data on a continuous basis to provide feedback to building
designers and operators who maintain and improve performance through equipment or
operational changes. Advanced meters and sensors are deployed at different levels (i.e. whole
building, system or component) depending on the size and complexity of the building.
Significant advantages over reliance on utility bills for performance feedback include:
•
•
•
Much easier and more reliable access to energy usage information for portfolio
managers, designers, energy efficiency programs and energy service consultants.
Immediacy of information, compared to waiting for bills to arrive at fixed intervals.
Additional detail (daily, hourly, sub-metering where desired), facilitating further
investigation into problems and tenant usage allocations.
This paper provides an overview of advanced metering and EIS, descriptions of where advanced
meters and EIS are providing value, perspectives regarding their utilization and pathways that
address impediments to advanced metering and EIS market penetration. Only advanced meters
and EIS used for permanent installation are considered. Data was gathered through literature
reviews and interviews with key industry personnel.
Motivations for Increased Advanced Metering and EIS Utilization
Persistence in Building Efficiency: Achieving and maintaining the performance of highly
efficient buildings will require effective monitoring with owner/operator feedback.
Evidentiary Design: There is little hard evidence of verified building performance; a 2007 study
of LEED buildings 1 carried out by New Buildings Institute showed wide variation in predicted
versus actual energy usage. For future buildings to improve, simpler and faster data collection
methods are needed to acquire this critical feedback and proof of performance
Advancing Building Performance Metrics: It’s likely that the next generation of energy codes
and building programs like LEED will call for performance requirements. Building Performance
Review and labeling programs will necessitate separation between tenant activity-driven loads
(such as plugs) and processes and the core and shell loads (such as HVAC and common area
lights) and require flexible metering and data acquisition.
1
Turner, C. and Frankel, F., 2008, Energy Performance of LEED New Construction Buildings, NBI Final
Report to USGBC.
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Components and Costs of Advanced Metering and EIS
An EIS is comprised of a set of advanced meters and sensors, a data acquisition system (DAS),
which collects the meter and sensor data, a gateway that transfers the data into a remote database
and software tools that display or analyze the data.
Meters: Advanced meter functionality and interval data can come from owner-installed
equipment or utility company meters or upgrades.
Owner-installed Advanced Meters - Owner-installed advanced meters are readily available
for electric, gas and water measurements. Electricity and natural gas are the most common
fuels in commercial buildings. The installed cost can be estimated to $800 per meter for
electric and $950 per meter for natural gas.
Utility Advanced Meters - Utility Advanced Metering Infrastructure (AMI) and Automated
Meter Reading (AMR) installations, which may provide EIS functionality to an owner, are
limited in availability. Estimates are that only 4.2% of all nonresidential installed electric
utility meters are capable of providing interval data. Costs for AMI meters for utilities, much
lower than owner-installed due to the economies of scale, range from $150 to $200 per meter.
Utility Meter Upgrades - An owner can gain building-level interval data by requesting the
utility upgrade their meter to a version with a standard local data output which can be read by
standard owner-installed EIS data acquisition hardware. Costs for an upgrade vary by utility,
anywhere from free to $2,000 or more; procedures for upgrading may be cumbersome.
Natural gas upgrades are not always available.
Basic EIS Cost Summary: Based on vendor estimates and assumptions regarding installation
costs, an owner can install a basic EIS to measure whole building usage of electric and natural gas
usage for $2,500 to $4,000, with an annual charge for communications, data storage and software
hosting of $0 to $240. This does not estimate any owner-related expenses such as staff training,
analysis labor or meter maintenance.
Data Analysis Methods
EIS software tools are available to analyze energy usage or interval data, or a combination of
both. Methods of analysis include:
•
•
•
•
Portfolio energy tracking – Enterprise Energy Management
Benchmarking and Baselining
Direct interval data analysis
Key Performance Indicators
Where are Advanced Metering and EIS Working?
In large commercial buildings, the energy expenditure is often sufficiently large enough to justify
installation of an EIS based on expected savings alone. One report estimates a minimum of
$40,000 of annual energy expenditure (or approximately 28,000 ft2 of floor space using average
expenditure numbers 2) as the minimum needed to justify installation of an EIS. The building
automation system (BAS) in these larger buildings may be able to collect and store trend logs for
2
Commercial Buildings Energy Consumption Survey (CBECS), Table C.4, US DOE, 2003
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energy use. These EIS are often called Integrated Platforms, Middleware or Energy Management
Control Systems. Vendors of integrated platforms which serve larger buildings reported that
client buildings must have a minimum annual fuel expenditure of $700,000 to $1 million.
For large buildings, two programs - Monitoring-based commissioning, MBCx (developed by
LBNL and the University of California system) and Continuous Commissioning® process
developed at Texas A&M university - demonstrate the effectiveness of using meter data on an
ongoing basis to assist and maintain commissioning projects These programs have been shown to
increase the persistence, magnitude and cost effectiveness of commissioning new and existing
buildings.
There is little data for the cost effectiveness of advanced metering and EIS for smaller
commercial buildings, i.e., those below the 28,000 ft2 estimate. According to CBECS 2003, Table
B22, 90% of buildings and 38% of commercial building floor space are smaller than 25,000 ft2.
Examples of small commercial buildings that do use advanced metering and EIS are chain
commercial properties, retail and hospitality where a single owner controls many stores. Also
federal, state and municipal government buildings to mitigate government energy expenditures as
well as comply with legislation.
Drivers for Increased Advanced Metering and EIS Installation
Availability: EIS hardware is well developed and current technology well suited to basic
performance monitoring and benchmarking. Costs have decreased in the last 10 years as
hardware, software, communications and data storage costs fall.
EPACT 2005 and EISA 2007: Section 103 of the Energy Policy Act of 2005 is requiring
managers of government facilities to install advanced metering at the whole building level
“…subject to determination of practicability.” As an example, the Government Services
Administration installed an EIS in 100 buildings nationwide as of 2009.
California AB1103: The State of California is requiring benchmarking, via EPA Portfolio
Manager, for all state buildings and eventually all buildings sold in California. Benchmarking by
the EPA can be automated through web services provided by EIS vendors.
Submetering: Owner-installed metering systems used for utility bill allocation (often called
submetering) to tenants use the same technology as EIS. Additional meters to enable whole
building or system Baselining and Benchmarking have a low marginal cost when a tenant submetering system already exists.
Demand Response: High value demand-response programs require interval meter data to verify
performance. Similar to submetering, the marginal cost of adding additional meters and analysis
functionality is reduced.
Carbon Accounting and Green Motivations: Advanced metering provides a building owner an
easy way to gather the information needed to calculate and report emissions.
Impediments to Increased Advanced Metering and EIS Installation
Awareness and Cost: Advanced metering is not often considered a basic element of new
construction or major renovation. The cost of advanced metering/EIS packages is sometimes
hard to accurately estimate, and potential benefits are not well understood. In interviews, the
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often-estimated savings potential for advanced metering and an EIS in commercial buildings is
5%, but as building size decreases there is less data regarding the expected savings percentage.
Marketplace separations between those who would purchase the equipment and those who would
benefit from it further complicate the decision making.
Shortage of Trained Personnel: Key performance indicators and benchmarking tools can be
automated to some degree, but the necessity for human interaction to monitor and interpret results
can never be eliminated. Smaller buildings tend to use fixed service contracts with HVAC
technicians to reduce costs. Even in larger buildings these technicians are typically not trained in
using energy consumption and interval data to make assessments or do not have the time to
employ interval data effectively.
Conclusions and Recommendations
Advanced metering and EIS hardware is well developed, and current technology is well suited to
basic performance monitoring and benchmarking. In light of the above discussion of drivers and
impediments, the following actions could increase the potential for achieving that objective:
•
Efficiency programs should consider automated metering options as a way to acquire
better and faster feedback on program results, while also providing the benefit of better
feedback to participants. Advanced metering and EIS equipment costs may decrease with
increased volumes, and general requirements or bulk purchasing for a widely used
program could provide an opportunity to reduce costs. The USGBC has announced its
intention to require performance data for LEED-NC buildings after 2010. Similar
requirements in efficiency programs, or in other state and local codes, would provide
similar benefits.
•
National benchmarking tools provide a simple number assessing building performance
relative to like-type buildings. Advanced metering and EIS provide opportunity to
enhance benchmarking immediacy and the potential to allow for expanded sophistication
of analysis in Benchmarking and Baselining.
•
A policy at the national level standardizing the cost to upgrade utility meters to pulse
output would provide clarity regarding costs to owners and allow for local interval
measurement of fuels without requiring owners to maintain the meters or the utility to
provide data from a secure database.
•
A simple and convenient software tool for the management of data is needed to permit
smaller building owners and their contractors to achieve the benefits of feedback from
advanced metering and EIS.
•
EIS hardware is capable of multiple measurements within a facility that can support the
isolation of energy systems to make more advanced forms of energy analysis, such as
Energy Infometrics and system-level benchmarking, possible. EPA may want to develop
tools to support certification of buildings based on these enhanced methods.
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1 Introduction
1.1
Advanced Metering and Energy Information Systems
Advanced metering is often mentioned as a component of a high performance building without
much description given to the nature or usage of the meter(s) or data collected. The generally
accepted definition3 is a meter that provides fuel usage measurements frequently (typically every
hour or less). The information is regularly gathered in a database where it can be analyzed with
software tools.
In commercial buildings, advanced meters form a core component of what is increasingly being
referred to as an Energy Information System4 (EIS), also referred to as an Advanced Metering
System 5. The EIS is a package consisting of advanced metering and other sensors, data collection
with remote communications and data storage and some form of software tool which the owner
(or designated representative) uses to analyze and monitor building performance. This definition
can include feedback displays for occupants and may provide design or financial feedback to
different elements of the owner’s staff.
The advanced meters that form the EIS can be installed to monitor any fuel used in commercial
buildings including natural gas, electric, fuel oil, heated or chilled water, or steam. The most
common fuels for commercial buildings 6 are electricity (99.8% of all commercial buildings) and
natural gas (54.2%), with the next closest being propane (10.2%).
The installation and use of an EIS can involve measurements at different levels of the building,
referring to what energy end-uses are captured in the measurement.
Whole Building, premises or site -The advanced meter measures usage for the whole site
including all systems, components and auxiliary loads. Installation may be by the owner or
the utility.
System or Subsystem - The meter measures the energy usage of a certain type of equipment
installed in the building (e.g. lighting, elevators, heating, cooling, core and shell, tenant
submetering). submetering installed to allocate the utility bill among tenants is considered
system-level metering in this report.
Component or Equipment - The owner-installed meter measures the input to a single piece
of building equipment, such as a boiler or chiller. Often this metering is combined with other
sensors that measure the output of such equipment in order to monitor the relative input-tooutput ratio.
There are more formal and complete taxonomies 7,8 that present order and definition of what
building systems consume with recommendations over calculations and trending.
3
Assessment of Demand Response and Advanced Metering, FERC, August 2006, Docket No. AD-06-2000, page vi
4
Motegi, Piette, Web-Based Energy Information Systems for Large Commercial Buildings, LBNL-4997,
May 2002, Lawrence Berkeley National Labs
5
Sullivan, Hunt, Pugh, Metering Best Practices, Federal Energy Management Program, US DOE, October
2007, page 2.1
6
Commercial Buildings Energy Consumption Survey (CBECS), Table B.22, US DOE, 2003
7
Bareley, Deru, Pless, Torcellini, Procedure for Measuring and Reporting Commercial Building Energy
Performance, NREL, October 2005
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The installation of an EIS, at whatever scale, involves costs and provides benefits that create an
overall value proposition for the owner. Some costs are relatively fixed (hardware, software, data
storage, maintenance). Others depend on building specifics (installation, tenants, integration with
existing building systems, maintenance procedures).
In addition to the hard and soft costs, owners must be able to act upon the new information either
through their own building staff or via the energy service consultant or service technician for the
building and its systems. Benefits of an EIS system come in the form of cost avoidance, either in
early detection of operating problems, feedback on cost trends, leveraging time-of-use (TOU)
rates in areas that apply, or adherence to regulatory/policy requirements.
1.2
Ownership Structure
The advanced meters that comprise an EIS may be installed by the owner, a third-party energy
monitoring service provider, or the utility.
Building Owner/Manager: Owners own and maintain the meters and analyzes the data
themselves. This is most common when the owner plans active utilization and has a capable
staff. Data storage is usually leased and software tools are third-party or supplied by the vendor.
Energy Monitoring Service Provider: An owner-selected third-party Energy Monitoring
Service Provider that offers a full-service package of equipment, installation, periodic status
reports, enhanced tools and perhaps even efficiency consulting and contracting services.
Utility Entity: The serving utility installs advanced electric, gas or water metering, perhaps as
part of an AMI. The owner, or an energy service provider retained by the owner, can access data
through a web portal and use the analysis tools provided or manually download interval data into
a third-party software tool.
1.2.1 Utility Installed Advanced Meters vs. Owner Installed Advanced
Metering
When a utility installs an advanced meter as part of an AMI, as discussed in Section 2.2, the only
meters affected are those for the building service accounts. For electric and gas, there may be
more than one account (and meter) servicing the facility, and the electric and gas utilities are
likely to be different companies. Thus the utility company installation of advanced metering for
gas may not occur simultaneously with an installation for electricity, and the data may reside in
different databases. In addition, utilities, for logical reasons, are concerned with data security;
however, the security measures, combined with the reasons above, often deter owners and energy
monitoring companies from using the utilities’ advanced meter data.
Owner-installed advanced meters provide an EIS with more flexible and consistent control over
the meter data and allow installation at any level of the building, with one database for all data
collection and, in most cases, more sophisticated tools for data analysis. This comes at a higher
per-site cost, presenting challenges for the owner wanting to justify initial costs on the basis of
anticipated, directly-related savings.
8
Gilespie et. al, A Specification for Performance Monitoring, Specifications Guide Version 1, LBNL,
March 2007.
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An important distinction between utility-installed and owner-installed advanced metering is that
owner installations can’t be used to support alternative rate structures. An often mentioned benefit
of advanced metering and EIS is the ability to respond to price signals9 to reduce costs. In order
to participate in alternative rate structures, the utility must install a meter that can monitor these
time periods. This meter may or may not provide the interval data according to definitions10 of
advanced metering, but owner-installed metering cannot be used for settlement of the
transaction11. Owner-installed metering may be used to “shadow” utility metering (i.e., installed
just downstream from the utility meter) and used as a proxy to change control settings to achieve
the desired effect at the utility meter.
The technologies used by utilities for metering, data collection and storage in an advanced
metering system are similar to technologies used in owner-installed systems. In general, electric,
gas and water meter technology is standard for all systems. The difference comes with the
method for data acquisition, which for utilities is on such a large scale that AMI installations can
employ more specialized methods that are amenable to mass installations. Owner-installed
metering is typically a site-by-site installation that must accomplish all the tasks of measuring,
data collection and storage individually.
This paper focuses on owner-installed EIS and discusses utility-installed advanced metering in
terms of availability and how the owner must work with the utility to acquire interval data from
utility advanced meters.
1.3
What is the Status of Owner-Installed EIS technology?
This paper provides an overview to the current technologies and descriptions of EIS components
and cost quotes from vendors for owner-installed hardware and included software, with some
basic clarifications of software capabilities.
This is followed by a discussion of some of the current and emerging analysis methods used in
conjunction with EIS equipment. Finally, the paper discusses motivations and impediments
toward greater market penetration for advanced meters and EIS.
Data was gathered from interviews with key personnel in the field of performance monitoring,
meter and energy management system vendors, utility energy managers and regulatory officials.
9
E.g. Time-of-Use Pricing, Real-Time Pricing, or Critical Peak Pricing.
Advanced Utility Metering, Architectural Energy Corporation, NREL SR-710-3359, 2003
11
Settlement refers to the process of establishing the amount and price of energy bought and sold. The
utility will only allow settlement with the utility-installed meter. As an exception direct load control
demand response programs often allow interval data from an owner-installed meter to be used for
settlement.
10
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2 Energy Information System Components
An Energy Information System for performance monitoring is comprised of a package of
advanced meters, data collection with remote communications and data storage, and software
tools which make it possible to collect and analyze energy usage data in nearly real time. More
detailed information can be found in the Metering Best Practices12, the Advanced Utility
Metering report 13, and several references from Lawrence Berkeley National Laboratory (LBNL).
This section briefly examines standard technologies and costs that are most common in practice,
with notable new product entrants, to provide a sense of typical costs.
The five basic components, illustrated in Figure 1, are:
1) Meter and sensors. The meter gathers energy use data from current or flow sensors and
transfers the data to the second element, a data acquisition system (DAS). There may or may
not be a display for site personnel to read. Other sensors which track conditions in the
building, such as temperature, light levels or on/off status, may also connect to the DAS.
Meters may automatically output data or be polled for data by the DAS at regular intervals thus the term interval data.
2) Data Acquisition System. The DAS coordinates collection of data from multiple
meters/sensors using a wired or wireless communications network. The DAS may be
standalone or part of a building automation system capable of data recording, with the data
typically stored as “trend logs.” Data is transferred from the DAS to the remote database via
the Gateway.
3) Gateway and Communications Service. A device that sends the meter and sensor interval
data from the DAS to the Remote Database at pre-selected times via a communications
service such as an internet connection, cellular, wireless, etc. The Gateway and DAS are
often combined into a single unit. The pre-selected time ranges from “instantly” to once
daily; communication costs vary depending on the frequency and amount of data collected.
4) Remote Database. A remote database server for data storage and processing, usually a webbased data repository provided by the vendor of the EIS equipment. Once in the remote
database, data is viewable using the fifth element, software tools.
5) Software Tools for Energy and Data Analysis. A web-based (or web-accessing) software
program that allows the user to access the Remote Database and review the data, use analysis
tools and set up reports. The predominant model in the industry is Application Service
Provider (ASP) where a web-based software tool accesses the remote database.
12
Sullivan, Hunt, Pugh, Metering Best Practices, Federal Energy Management Program, US DOE, October
2007
13
Advanced Utility Metering, Architectural Energy Corporation, NREL SR-710-3359, 2003
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Figure 1.
The process diagram for data collection from meters to software tools
These five data collection functions are not always contained in separate pieces of equipment;
frequently the same vendor offers all the components from the DAS to the software tools.
Advanced meters are more interchangeable and can be purchased from individual vendors as long
as they conform to the DAS communication method of the EIS.
2.1
Metering Technology
This section provides basic descriptions of advanced meters as background for the later
description of components needed to implement an EIS. Prices are given as a range typical for
the most common equipment and for a retail purchase by an individual owner, as of winter 2008.
2.1.1 Electric Meters
Basic electric meters measure energy over time, much the same way a car’s odometer measures
miles traveled. Total energy flow past the meter is tracked through one or more wires, or phases,
by measuring the current and voltage for each phase.
Advanced electrical meters with display and a data port cost $200 - $300; sensors are sold
separately for $40 - $80 per phase with separate voltage sensors. Cost of installation will vary and
requires an electrician or trained facility personnel.
Newer products may not look like a classic “meter” with a display. A new low-form factor meter
combines the sensing and signal processing in a single enclosure with a simple industry standard
data output. The devices are installed in electrical panels and cost between $400 - $700.
2.1.2 Natural Gas Meters
Natural gas meters measure a volumetric flow of gas, which represents a certain amount of
energy content. Ambient temperature and pressure affect the measurements, so most meters are
installed downstream of pressure regulators and use a temperature compensation adjustment to
ensure accuracy. The two most common types of gas meter are diaphragm and rotary.
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Diaphragm meters measure gas flow using a volumetric bellows and are used frequently by
utilities and often by owners as performance or sub-metering meters. They are inexpensive and
don’t require frequent calibration; however, as gas flow rate increases, they can become quite
large in size. The cost is $150 - $500 dollars depending on size and output data to a display or
data port, or both.
A rotary meter uses a rotating propeller to indicate volumetric flow and is typically smaller than a
diaphragm meter. They are calibrated for temperature and pressure and output usage information
to a display or data port. These meters cost $300 - $500 depending on flow capacity. They are
better suited to higher volume flow rates where the diaphragm meter may be too large. Rotary
meters require more frequent calibration.
2.1.3 Additional Meters and Sensors
To enhance their monitoring packages, many vendors offer additional sensors which are
compliant with the DAS communications. Additional sensors include temperature, humidity,
occupancy sensing, light levels, on/off, etc. While not directly addressed in this paper, they may
be useful in addressing specific operational problems or to augment the meter data in diagnosing
operation problems.
Buildings in the northeastern U.S. and campus/district buildings may use fuel oil, steam or
heated/chilled water as a primary fuel. As mentioned in the Introduction, they are much less
prevalent in commercial buildings than electricity and natural gas, so are not detailed here.
Meters 14 can be purchased for these fuels that use standard data output signals to incorporate into
a Data Acquisition System.
14
Sullivan, Hunt, Pugh, Metering Best Practices, Federal Energy Management Program, US DOE, October
2007
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2.2
Utility Meters: Upgrades and Advanced Metering
Infrastructure
Most facilities already have utility meters at the whole building level which an owner can
leverage to gather site-level interval data. In some cases this can be less expensive than an ownerinstalled meter. The type and functionality of a utility meter installed in or planned for a building
determines the options for how that meter can be interfaced to gather the desired data.
•
•
If the meter is a conventional water, gas or electric mechanical or solid-state device with
no data collecting capability, either:
o Install a Meter Dial Reader that electronically reads the dials off the display, or
o Request a utility upgrade to a version that provides a pulse output 15 proportional
to the metered use and can be read by an owner-installed EIS.
If the meter is already an AMI or AMR meter capable of collecting interval data:
o Retrieve the data directly from the utility database, or
o Request a replacement AMI/AMR meter with a local pulse output.
2.2.1 Meter Dial Reader
Attached to conventional dial meters, these monitor the physical turning of the disk or dial that
indicates usage on a gas, electric or water meter. This type costs approximately $200 and
typically uses a pulse output to indicate usage. Some industry practitioners do not consider this a
robust solution due to the impermanent nature of the attachment and a relatively higher error rate.
2.2.2 Pulse Output Upgrade
The total cost of a utility pulse-output upgrade varies from $0 – $2,000 16 or more for electric
meters, depending on utility. Some charge a monthly fee for the pulse output in addition to the
one-time upgrade charge. The variation in upgrade policy and price reflects the wide variation in
business practices from utility to utility. Upgrades from gas meter to pulse output are generally
not as available from utilities as electric meter upgrades. In addition, some meters are not
suitable for upgrade due to the nature of the dial display.
The time between a request for a meter upgrade and the installation may be weeks or months and
may require an application process.
2.2.3 Utility AMI and AMR Meters:
The utility industry is now discussing establishment of a “smart grid.” Part of the smart grid
concept relies on detailed energy use data at all customer meters. The data are provided via an
AMI 17 for all customers in a service territory, leveraging it to improve customer service and
reduce operating among other stated goals 18. AMI installation may also communicate bidirectionally to send price signals and other information to the meter. Benefits to the commercial
building owner are:
15
A pulse output is a very common meter data communication method. The electric or gas meter will
provide an electronic pulse when it measures a certain amount of usage.
16
Various interviews.
17
Assessment of Demand Response and Advanced Metering, FERC, December 2008
18
Ibid, page 12
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Advanced Metering and Energy Information Systems
•
•
Utility meter data at intervals of one hour or less and the ability to retrieve data to a
central storage point at least daily.
The potential for daily access of meter data in a utility database and some graphical
energy tracking tool.
The term Automated Meter Reading, an earlier technology than AMI, only moves information in
one direction - from the meter to the utility.
Some utilities with AMI/AMR systems offer basic web-based analysis of data and trends for
account holders, typically at no charge. The capabilities and analysis methods differ, but all offer
access to raw hourly interval data. Some utilities are incorporating advanced functions such as
benchmarking through Energy Star’s portfolio manager, but often the AMI meter only measures
gas or electricity individually. The utility can provide management and forecasting functions but
will not represent total facility usage information.
Relatively few AMI meters are currently installed. A recent report 19 noted market penetration of
nonresidential meters at 4.2%. This defines the percentage of meters providing hourly data each
day. Older technology and AMR systems may provide interval data less frequently, which can
still be useful in facility analysis. The lowest technology meter, with no communication or
interval capabilities, still comprises 85 million out of 145 million electric utility meters in North
America though 52 million AMI meter installations are now reported to be announced.
Table 1 summarizes the penetration of both residential and non-residential utility meters in the
U.S.
Table 1. Electric AMI penetration by state for residential and non-residential customers 20.
State
Advanced Metering
Penetration (%)
23.9
13.8
11.3
8.9
8.7
8.6
8.0
8.0
7.6
6.6
Pennsylvania
Idaho
Arkansas
North Dakota
South Dakota
Oklahoma
Texas
Florida
Georgia
Missouri
19
20
Assessment of Demand Response and Advanced Metering, FERC, December 2008
Ibid, page 30
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Advanced Metering and Energy Information Systems
2.3
Data Acquisition, Communication, and Storage
The data acquisition process collects data from meters and sensors and sends it to a remote
database via a gateway. Meters and sensors output a signal at a data port to indicate the quantity
measured. The signal is some form of industry standard which may be as simple as a pulse output
(a simple voltage pulse that indicates a certain quantity of commodity has passed the meter) or as
complicated as a formal data protocol like TCP/IP or ModBUS 21. The meter is purchased to be
compliant with the chosen DAS.
2.3.1 Data Acquisition System
The simplest method of DAS communications is direct wiring: a set of current or flow sensor
outputs are directly wired to the DAS/Gateway. This means no “meter” in the sense of a display
with dials or a digital screen. This type of DAS/Gateway is usually designed to handle a small
number of inputs, typically fewer than 16. When multiple meters and sensors are used or if the
distance between meters and the DAS is large, a networked DAS communication method (either
wired or wireless) is needed.
In general, wired communication22 is better for situations with fewer meters that are in close
proximity or if there is an existing building automation system or local area network (LAN) that
can be used to gather the data.
Wireless communications are recommended when larger numbers of meters must be installed and
there is no easy access for wiring. Installing long runs of data cable can rapidly become more
expensive than the EIS components themselves. There is a trade-off, however, between cost and
communications reliability, which can be a problem with a wireless network.
One notable communications method gaining in popularity is wireless-mesh, which is relatively
robust compared to ordinary point-to-point wireless. Each component in a wireless mesh system
communicates with its neighbors to form a network, creating a flexible set of sensors and meter
points that can be easily moved around. Some meters have a wireless communication system built
into the meter itself, while some use components that serve as an interface which inputs a meter
output signal and communicates it wirelessly to the DAS. As of 2008, standards are still in
development, though no clear standard is widely available allowing vendors to interchange
wireless mesh components.
Notably, some owner-installed meters are equipped with a web server 23 that connects to a LAN
and provides data via a firewall to the remote database. This method removes the extraneous DAS
equipment but does not alleviate the management issues that arise with utilizing the LAN for
communication with the remote database, as discussed in 2.3.3.
2.3.2 Building Automation Systems, Integrated Platforms, and Middleware
Larger buildings are often outfitted with a Building Automation System which controls
equipment to maintain comfort and schedule operations in the building. Some BAS are capable of
collecting, storing and outputting data from meters and sensors, often called trend logs, like a
21
MODBUS is the most common electrical meter communication protocol
This can be misleading as direct wiring of meters often uses one or two individual wires but networked
protocol-based DAS some form of data cable.
23
Energy Advantage
22
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July 3, 2009
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Advanced Metering and Energy Information Systems
Data Acquisition System. These BAS are sometimes leveraged 24 to provide the EIS functionality
without the costly installation of meters, sensors and a DAS.
Since larger buildings have higher fuel costs, they are often good cost/benefit candidates for EIS
and performance monitoring. A number of vendors have emerged to serve this market. Some
energy monitoring service providers can reprogram the BAS computers to provide an automated
data transfer to the remote database via a standard data format. Comma-separated value (CSV)
files are a standard, but increasingly the BAS industry is experiencing a dramatic convergence 25
with IT-based technology, and XML is becoming the standard.
Other vendors of products called integrated platforms, or middleware, create an overlay for the
BAS that extracts data and changes control settings using web-based tools in a more sophisticated
fashion than the original BAS designer intended. Middleware vendors usually focus on very large
buildings 26 and sell hardware and software that utilize the latest in IT technology to enhance the
often older technology BAS. Recently several acquisitions 27 underscored the converging nature
of this and the BAS industry in general. This convergence may allow for smaller buildings to
merge IT needs with energy management, reducing costs to just the marginal equipment cost.
The presence of an existing BAS does not guarantee its suitability or that it is the best choice for
performance monitoring. Retrieval of trend logs for transfer into a remote database can be
difficult; meter measurements can be non-totalizing, which does not provide meaningful usage
data. An independent meter reading DAS can allow for sophisticated analysis without getting into
the murky details of BAS operations (which can be proprietary). Costs for middleware
technologies are highly specific and usually packaged with a sophisticated software tool and
sometimes full-time energy monitoring; the costs are therefore not stated here.
Some vendors 28 are increasingly offering control system products that may be attractive to
owners of small commercial buildings. This may encourage participation in demand-response
programs, perhaps improving the value proposition enough to prompt installation of a system that
includes advanced meters and regular performance monitoring.
2.3.3 Gateway and Communications Service
In computing, the term “gateway” refers to a device which interfaces two systems that use
differing communications protocols. For an advanced meter or EIS package, we use the term to
refer to the device that transmits data collected by a DAS to a remote database, usually via a
telephone modem or LAN, although satellite and cellular data service is becoming increasingly
affordable. The gateway and DAS are frequently combined in a single unit.
24
Kiliccote, Piette, Advanced Control Technologies and Strategies Linking Demand Response and Energy
Efficiency, ICEBO Conference Paper, September 2005
25
McGowan, Convergence, Energy User News, November 2003
26
A minimum of $700,000 and $1 million in annual energy expenditure per site was estimated by two
vendors
27
Press releases: Cisco Acquires Richards-Zeta Building Intelligence, Inc. – January 27, 2009 ; Johnson
Controls Acquires Software company Gridlogix – October 20, 2008
28
Demand Response Enabling Technologies for Small-Medium Businesses, Prepared by Lockheed Martin
for Southern California Edison, April 2006
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Advanced Metering and Energy Information Systems
Table 2 describes available communication options and estimated monthly pricing. Costs vary
depending on amount of data retrieved and frequency of retrieval. All vendors can accommodate
at least phone and LAN communications.
Many vendors will package the monthly communication costs with data storage and analysis
software, so communications costs may not be expressly quoted. Note that using an existing LAN
at the building is technically free (the marginal cost for the data transfer is zero), but there may be
a labor component by the owner’s IT department or ISP. At times, utilizing LAN communications
has resulted in IT issues with firewalls and protections, though vendors have become more adept
at dealing with these issues. Some vendors use only cellular communications, which are more
expensive but eliminate firewall concerns.
Table 2. Gateway Communications Typical Service Cost Estimates
Service
Dedicated
telephone modem
Local Area
Network (LAN)
Dedicated
Cable/DSL Modem
Cellular
(GSM/GPRS or
CDMA)
Wi-Max
Wi-Fi
Typical Monthly
Cost
Comment
30
0
60 +
30 – 250
No cost information
0 – 30
Dedicated and hardwired phone line
monthly cost. Limited data capacity.
Phasing out in favor of LAN/cellular.
Using exiting LAN with modem. May
have firewall problems.
Connect a modem directly to Gateway.
Expensive but reliable.
Expensive but eliminates wiring and
LAN issues. Costs depend on data
interval and upload frequency.
Emerging technology. Initial prices are
comparable to cellular.
Need existing Wi-Fi network. Costs
depend on data interval and upload
frequency.
2.3.4 Database and Data Storage
It is often most cost effective to use the vendor of the DAS/Gateway equipment to provide secure
web-based data storage. Storage, as well as an analysis package, is often included in the initial or
monthly price. The data may also be stored with a third-party software provider.
Storage costs are often not mentioned as a cost component. Vendors may not store data for long
periods, i.e. more than a few years, in order to reduce the burden of data storage.
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July 3, 2009
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Advanced Metering and Energy Information Systems
2.4
Software Tools
Advanced meters provide interval data as shown in the example in Figure 2. A date and time
stamp accompanies the desired meter data. 15-minute intervals are an industry standard, but
longer and shorter intervals may be used for different purposes. This basic data table is useful
only with tools to summarize and report results with a variety of views and detail levels.
time
US/Pacific
1/28/08 6:45
1/28/08 7:00
1/28/08 7:15
1/28/08 7:30
1/28/08 7:45
1/28/08 8:00
1/28/08 8:15
1/28/08 8:30
1/28/08 8:45
Whole Building
Plugs and Light
rate
energy
rate
rate
energy
demand
demand rate min max
use
min
max
use
(KWH)
(kW)
(kW)
(kW)
(KWH)
(kW)
(kW)
(kW)
1483.0
2.0
1.726 2.034
583.7
0.8
0.570
0.571
1483.3
1.2
1.254 1.685
583.7
0.4
0.570
0.570
1484.4
4.4
1.233 5.921
583.8
0.8
0.571
0.588
1484.9
2.0
1.915 3.495
583.8
0.8
0.626
0.744
1485.2
1.2
1.501 1.865
583.8
0.8
0.772
0.792
1485.5
1.2
1.189 1.349
583.8
0.8
0.762
0.800
1486.8
5.2
1.306 6.164
583.8
1.2
0.764
1.042
1489.6
11.2
6.061 17.143
583.8
1.6
1.327
1.453
1491.5
7.6
7.563 8.145
583.8
1.2
1.429
1.440
Figure 2. Sample of raw interval meter data
Basic EIS: Vendors of basic owner-installed EIS equipment usually have an energy management
software package that allows for various levels of sophistication in interval data visualization;
however, they rarely offer detailed analysis tools except in conjunction with packaged consulting
services.
Third-Party Software Tools: Some third-party software tools originated as energy accounting
software which allowed an organization’s financial personnel to track the utility or billed fuel
expenditures for multiple sites. These Enterprise Energy Management tools have incorporated the
ability to use advanced meter data to a greater or lesser extent, but not all tools permit analysis of
meter and sensor data from lower levels of the building systems and major components.
Other third-party tools arose from building analysis research 29 and can provide detailed site,
system and component monitoring with advanced graphical representations and statistical
regression analysis.
Some utilities with AMI or AMR systems in their territory have developed energy management
software that is accessible through a portal for the account holder. A well-known tool developed
by ABB is Energy Profiler Online, which is used by several electric utilities. Complete energy
tracking, or other site energy analysis, require both electric and gas data which may not be
available to the utility offering the portal.
Integration Platform vendors provide advanced functionality and control feedback that optimizes
facility operations, often in conjunction with full-time monitoring and analysis. These tools are
very advanced, similar to the research-developed tools.
Approximate categories for features are described in Section 2.4.1 through Section 2.4.3 based on
several references. 30, 31
29
Katipamula, Bauman, Pratt, Brambley, Demonstration of the Whole-Building Diagnostician in a SingleBuilding Operator Environment, PNNL-14239, 2003
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Advanced Metering and Energy Information Systems
2.4.1 Basic Software Tool Features
A basic web-based tool provides:
•
•
•
Tabular and graphic summaries of total energy use by month and year, for each fuel and
the total of all fuels
Tabular and graphic displays of daily demand profiles
Capable of downloading data sets to spreadsheet
2.4.2 Intermediate Software Tool Features
Advanced software packages provide a higher technical level of analysis and allow for
incorporation of meter data from all levels including whole building, subsystem and component.
Accounting-focused software may not allow for system or component level data but will track
performance metrics and EPA’s Portfolio Manager score and may be capable of basic predictive
analysis.
•
•
•
•
•
Automated calculation and tracking of energy use index (EUI) and automated
benchmarking through the EPA Portfolio Manager or other tool
Modest statistical analysis to identify unusual trends
Weather normalizing capability, with options to combine other normalizing metrics
Multiple options for time series visualization, overlapping and trending
Adroit management of data from multiple meters including performance indicator
analysis for each component
2.4.3 Advanced Software Tool Features
The most advanced software packages incorporate most of the above attributes and offer further
analysis, often requiring multiple meters at different levels and some customization.
•
•
•
•
•
•
•
Neural network-based analysis of trends
Sophisticated statistical regression analysis
Detailed equipment performance monitoring for HVAC components.
Automated and detailed building energy modeling to compare with interval data
Detailed time block-differentiated predictive algorithms and display techniques
Separated financial asset management, facility management, and design feedback
performance indicators
Multiple time series visualization tools
Researchers at LBNL will be releasing a more detailed study in 2009 regarding available software
tools, their capabilities and costs.
30
Motegi, Piette, Web-Based Energy Information Systems for Large Commercial Buildings, LBNL-49977,
May 2002, Lawrence Berkeley National Labs
31
Better Bricks website: http://www.betterbricks.com/DetailPage.aspx?ID=518, accessed 3/2009
New Buildings Institute
July 3, 2009
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Advanced Metering and Energy Information Systems
3 Costs for Basic EIS Technology
This section describes the costs for a “basic” owner-installed EIS consisting of whole building
electric and gas service. The costs in Table 3 reflect the estimates of selected vendors in 2008 to
provide the DAS/Gateway, remote communications, data storage and default software tool
capable of measuring site electricity and natural gas for a building. Advanced metering costs are
not included in Table 3 but are estimated in Table 4 so total capital cost may be estimated.
Many circumstances can affect the cost of a system, and any installation should identify
organizational goals and limitations before pricing systems. Integrated platforms, BAS-based and
utility-installed EIS are not cost estimated.
Table 3. Estimated Costs for DAS/Gateway, Storage, and Software Tools for Selected Vendors
Vendor
DAS and
Gateway
($)
Extra Costs
Annual
( + One-time
Set-up)
DAS
Communications
Type
Number of
Hardwired
Points per
unit (N)
Software
Analysis
Capability
Level
A
800
0 (+90)
hardwired
16
Basic
B
700
60
wireless mesh
0
Basic
C
1650
200 (+200)
hardwired
4
Basic
D
500
250
hardwired
16
Intermediate
E
750
1200
hardwired
n/a
Advanced
F
800
0
hardwired
4
Intermediate
Additional
Comments
LAN gateway
communications
included
LAN gateway
communications
included
Software has data
viewing and
download only
Monitoring and
Reporting
included
Monitoring and
Reporting and
cellular gateway
included
Full Service
Mechanical
Consulting And
Monitoring
Required
Installation costs also vary by many factors. For general information purposes the time required
for site-level advanced meter installations is shown in Table 4.
Table 4. Estimated labor requirements for whole building level meter installations 32
Estimated
Typical Hours
Type
Description
Labor Type
Total Installed
to Complete
Cost ($)
Electric
Sensor Installation
2–4
Electrician
800
Meter install with
Gas
>4
Tradesperson
950
Service Interruption
The total cost range for an owner-installed basic EIS with electric and natural gas metering is
$2,500 - $4,000.
32
Source: NHT Technologies
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July 3, 2009
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Advanced Metering and Energy Information Systems
4 Data Usage Analysis Methods
Ideally, advanced meter data is analyzed using software tools to simplify building operation and
management. The intricacy of analysis increases with the complexity of major systems and
methods of heating and cooling distribution. While discussion of all methods is outside this
paper’s scope, certain methods have become popular for buildings at different levels, including:
•
•
•
•
Portfolio energy tracking – Enterprise Energy Management
Benchmarking and Baselining
Interval data analysis
Key Performance Indicators (KPI)
As advanced metering and EIS hardware costs decrease, there are opportunities to apply more
advanced automated diagnostic tools to these standard analysis methods.
4.1
Portfolio Energy Tracking
Energy use comparisons between different sites must be normalized for area. By comparing the
energy use per square foot (energy use index, or EUI), a portfolio of buildings can be tracked.
EUI is calculated monthly or annually, and buildings within a portfolio are compared against each
other. Financial metrics and utility bill verification are often features of tools that perform energy
tracking and enterprise energy management (EEM). Some EEM software tools can accommodate
advanced meter data; others only use utility account, or billing, data.
Tracking this basic EUI information, at the level of the whole building and combination of all
fuels, can help identify major changes over time and the best and worst performing buildings in
the portfolio. To understand more about what is driving those differences, it is essential to view
data in at a more detailed level.
4.2
Whole Building Energy Benchmarking and Baselining
Energy benchmarking generally means comparing a building’s energy use to that of comparable
buildings or other relevant target. “Comparable” in this sense means adjusted or normalized to
reflect similar climate and activity-based energy requirements (schedule, plug loads). The most
well known U.S. basis for benchmarking is from Energy Star Portfolio Manager. California also
has a state-specific tool, Cal-Arch, developed by LBNL. These tools are similar in methodology
but differentiated by the data set used to create the baseline against which the energy performance
of a given building is compared.
Figure 3. Energy Star ratings in Portfolio Manager
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Advanced Metering and Energy Information Systems
The Portfolio Manager tool normalizes results for building activity type, temperature, occupancy
and location by comparing a building’s EUI for a year with like-type buildings created from a
linear regression of the US Department of Energy CBECS data set.
Some energy management software tools incorporate automated upload of data to Portfolio
Manager, using EPA’s XML web services capability, which eliminates the user’s need to
separately enter information in that tool. Monitoring service practitioners report 33 this is a
motivator for building owners to install advanced metering and EIS. Automated ratings provide a
convenient way to establish benchmarked evidentiary data on high performance buildings.
Energy Baselining refers to comparing energy performance in a period to a base period, typically
one year, to monitor for deviations or evaluate achievements of implemented changes.
Baselining may be applied at the whole building, system or equipment level. Examining the
change in the Portfolio Manager score over time is a method of Baselining. Baselining becomes
more valuable as the metrics are normalized, i.e. applying statistical analysis to remove variations
due to weather, occupancy, and other variables.
4.2.1 Temperature Normalization and Temperature Independent Analysis
Temperature or weather normalization usually refers to adjusting measured energy data for
particularly high or low temperatures during the period, relative to an average weather year. The
normalized results permit year-to-year comparisons that show changes in building efficiency or
occupant requirements, not distorted by weather-related differences in heating or cooling needs.
Weather-based differences in full-year heating and cooling energy of a commercial building are
not typically large in relation to total annual energy use, but normalizing for these variations is
essential in comparing an individual month’s energy use or to quantify changes from efficiency
programs.
Isolating the impact of temperature differences can be accomplished by explicitly plotting EUI
for a given period (such as a billing period) against average temperature or a degree-day
calculation. Figure 4 shows one example of relating energy use to temperatures, which much
more clearly displays that current year heating use (green squares and dotted line) has been higher
than the base year in cold weather (here expressed in degree days rather than °F).
Figure 4. Temperature-normalized savings (Utility Manager)
33
Various interviews
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Advanced Metering and Energy Information Systems
When plotted against average temperature for billing period, the EUI can be used to identify in
which season a building may be experiencing problems as opposed to conventional benchmarking
which provides only an annual number. This is sometimes called an “energy signature.” Figure 5
shows an energy signature with area-normalized power on the y-axis and average temperature
during the measurement period on the x-axis.
Figure 5. Example of an energy signature
4.2.2 Additional Normalization, Energy Informatics and Energy Signatures
Going a few steps further than the energy signature, Energy Informatics34 is a methodology of
using multi-variable change point regression (MVR) models to add mathematical regression to
normalize for weather, as well as other factors such as occupancy and then using Baselining to
track building performance persistently. While the Energy Star normalizations referred to above
quantify some of these correlations for the building stock at large, MVR identifies the
relationships for the particular building being studied. In some cases, identification of
unexpected correlations may point to areas to investigate for possible problems. Through MVR
and interval data, site-level building performance can be used to baseline building performance
and perform weekly or daily tracking to look for deviations.
Identifying the building-specific relationships between energy use and key independent variables
such as occupancy that affect this use provides a solid baseline quantifying the achievements of
new efficiency measures. The identified relationships can be used to normalize for changes in
occupancy or other key units, isolating the impact of adopted measures. This method mimics
approaches in Measurement and Verification (M&V) that establish energy savings attributed to
energy efficiency measures. Using basic assumptions of the building systems, system-level uses
can be isolated and tracked individually.
4.3
Time Series Visualization Tools
The basic data logged by interval meters consists of a list of time-stamped energy usage as shown
in Figure 6, instantaneous power (BTU rate or kW), and possibly other sensor measurement (°F,
humidity) at intervals such as 5, 15 or 60 minutes. While the benchmarking examples above
34
Seryak, Applying State-of-the-Art Analysis to Utility Billing Data, Presentation to Ohio Board of
Regents, Go Sustainable Energy, April 2006
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Advanced Metering and Energy Information Systems
come from viewing usage on an annual or monthly basis, interval data load profiles can identify
whether equipment is left “on” during off hours or if there is a potential benefit to shifting loads
to off-peak hours for reduced costs from a time-of-use rate plan. Monthly utility bills cannot
provide this level of detail.
Advanced interval data trending tools use graphical representations to simplify spotting
irregularities. These tools include three-dimensional plotting, overlaying similar day types.
Graphical trending methods can simplify the identification of aberrant behavior. Research is
continuing into rule- and modeling-based approaches to automating detection of aberrant
behavior, reducing the burden of analysis on energy managers.
A simple standardized tool combining common time series analysis methods with common
performance metrics like benchmarking may increase utilization of meter data by the owner or
owner’s service contractor.
4.4
Key Performance Indicators
Many useful indicators can be calculated from relationships between two or more meters or
sensor points. The resulting indicators - typically referred to as Key Performance Indicators - do
not explicitly diagnose problem in these areas but rather direct the building engineer toward
particular systems to determine the source of deteriorating performance. A few examples:
Chiller performance (kW/ton): This ratio of electric power (in kW) to the chiller divided by
chilled water production (in tons) should be within certain performance limits when the chiller is
operational. 35
Figure 6. An example of research involving KPI for chiller performance.33
Boiler efficiency (BTU/BTU): This KPI measures the boiler output delivered to the space using
a BTU meter compared to the amount of natural gas input when the boiler is operational
expressed as an efficiency ratio. A drop in ratio warns of deteriorating performance.
35
Erpelding, Ultra-Efficient, All Variable Speed Chiller Plants, A Green Imperative, National Conference
on Building Commissioning, April 2008
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Advanced Metering and Energy Information Systems
5 Areas of EIS Utilization and Research in Commercial
Buildings
Analysis of buildings using EIS has been occurring in several sectors of commercial buildings
where either the cost effectiveness is well established or other research or regulatory/policy
motivators have incentivized the buildings.
5.1
Large Commercial Buildings
In large commercial buildings, the size of the energy expenditure is often great enough to justify
installation of an EIS. A recent FEMP training session estimated an annual energy expenditure of
$40,000 was necessary to justify installation of “advanced metering.” CBECS 2003 estimates an
average of $1.43/ft2 in fuel expenditures; this approximately defines a “large” building as 28,000
ft2 or larger. According to CBECS 2003, this represents 90% of buildings and 38% of total, nonmall, commercial floor space. Another energy efficiency practitioner gives an estimate in terms of
square footage of building space with 100,000 ft2 as a rule-of-thumb minimum for installation of
a basic EIS monitoring electric and gas usage. Two vendors of middleware solutions, which
target larger buildings, placed the minimum building annual energy expenditure at $700,000 and
$1,000,000 respectively for cost-effective consideration.
CBECS evidence points out the lack of energy management equipment by noting that only 4% of
buildings under 50,000 ft2 have an “Energy Management Control System36.” Unfortunately,
buildings under 50,000 ft2 represent 50% of all non-mall commercial floor space.
Interviews with energy monitoring service providers reinforce the focus on larger buildings for
profitable application of an EIS, though the metrics are varying and subjective. Further, service
providers report that advanced metering is less useful for natural gas monitoring than for
electricity.
The cost effectiveness of EIS in large commercial buildings is generally agreed to be high, as
shown by several efforts in research:
•
Monitoring-based commissioning (MBCx) programs, where meter data is used on an
ongoing basis to assist and maintain commissioning projects has been shown to
dramatically increase the persistence, magnitude and cost effectiveness of
commissioning new and existing buildings 37. The savings in total commissioning
programs is reported as 15% with a 0.7 year payback, suggesting that permanent
monitoring via EIS can improve savings even more dramatically. So far these
programs are limited to college campuses but are now offered as a service by energy
monitoring companies.
•
The Continuous Commissioning process developed at the Texas A&M Energy
Systems Laboratory is a similar approach to building energy management where
36
Energy Management and Control System (EMCS): An energy management feature that uses
mini/microcomputers, instrumentation, control equipment, and software to manage a building’s use of
energy for heating, ventilation, air conditioning, lighting, and/or business-related processes. These systems
may also manage fire control, safety, and security. Not included as an EMCS are time-clock thermostats.
CBECS 2003, Table B6. Building Size, Number of Buildings for Non-Mall Buildings, 2003
37
Criscione, What’s Working with Existing Building Commissioning Programs, E-Source, ERDP-F-23,
2008
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July 3, 2009
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Advanced Metering and Energy Information Systems
monitoring via an EIS provides constant feedback to maintain performance in
improved efficiency systems. Energy savings and cost data exist for more than 130
buildings that show an average payback of 0.7 years.
Some areas where advanced meters and EIS have made inroads are situations where economies of
scale or regulatory mandates exist.
5.2
Chain Commercial Buildings
Some vendors of EIS equipment are focusing on chain store applications where economies of
scale permit installation of metering in what would not otherwise be a cost-effective situation.
This is done for the purposes of portfolio management and cost tracking. Hotels and retail outlets
also present a good opportunity for energy monitoring and tracking.
5.3
Campuses and Government Facilities
University campuses and government facilities are installing EIS to allocate utility costs and
improve energy performance. Despite additional regulatory drivers described below, campus and
government-owned buildings represent a situation where a single decision-maker is managing a
portfolio and the value proposition is improved.
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6
Advanced Metering and EIS Penetration
EIS not only provide information to the owner but also provide data that can be used to gather
information regarding building performance.
Persistence in Building Efficiency: The path to achieving net-zero energy buildings will
typically require buildings which are 70% to 80% more efficient than standard practice. These
buildings, both new and renovated, must continue to perform at these high levels of efficiency for
their entire useful life; real-time performance monitoring with owner/operator feedback becomes
critical.
Evidentiary Design: Surprisingly, there is little hard evidence correlating design and verified
building performance. An initial 2007 study of LEED buildings carried out by New Buildings
Institute showed little correlation between design and performance. Proof of performance is
critical, both for proving out winning design elements and for continuous improvement that can
lead to net-zero buildings.
Advancing Building Performance Metrics: The next generation of energy codes and building
programs may call for a departure from standard practice with regard to building performance
reporting. Individual systems may have performance requirements to separate out effects from
discretionary loads like plugs, tenant lights and processes from the core and shell loads like
HVAC and common area lights.
6.1
Drivers for Increased Advanced Metering and EIS
Installation
Availability – EIS hardware is well developed, and current technology is well suited to basic
performance monitoring and benchmarking. It can also be scalable to use with more advanced
methods of analysis. Costs have decreased in the last 10 years as hardware, software and data
storage costs are decreasing. Wireless communications, whether from meter to DAS or from
Gateway to database, assist in reducing the cost of advanced meter installations at system and
component levels and are used frequently in sub-metering applications.
Regulatory – Section 103 of the Energy Policy Act of 2005 is requiring managers of government
facilities to install advanced metering, at the whole building level “…subject to determination of
practicability.” As an example the Government Services Administration installed an EIS in 100
buildings nationwide as of 2009.
EPA Portfolio Manager Interface and Automated Updates – One of the most often perceived
advantages to owners for energy management is the ability to automate Portfolio Manager
Benchmarking. A basic EIS is capable of automatic updates via XML transfer using the Portfolio
Manager system.
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Small Building Control Systems – Emerging companies designing wireless communicating
control systems 38 for smaller buildings. Enabling energy management or demand response in
smaller building may provide the value to justify the cost of advanced meter installation.
AMI/AMR installations – AMI/AMR systems provide the hardware side of an EIS, providing a
cost savings to the owner. Ideally these can be used by the owner to track energy performance.
Data Use Innovators Entering Marketplace – New companies are developing software and
software/hardware solutions to address the energy analysis needs of the marketplace. Energy
feedback through building displays and web tools is gaining popularity.
California AB1103 - The State of California is requiring benchmarking, via EPA Portfolio
Manager, for all state buildings and eventually all buildings sold in California. The utilities and
state are working together to upload billing and AMI data when available, while maintaining
confidentiality. This legislative requirement may drive owners to purchase advanced metering
and EIS to automate compliance.
Submetering – Owner-installed metering systems used for utility bill allocation (often called
submetering) to tenants use the same technology as EIS. Additional meters to enable whole
building or system Baselining and Benchmarking have a low marginal cost when a tenant submetering system already exists.
Demand Response – High value demand-response programs require interval meter data to verify
performance. Similar to sub-metering, the marginal cost of adding additional meters and analysis
functionality is reduced.
Carbon Accounting and Green Motivations – Advanced metering provides a building owner an
easy method to gather the information needed to calculate and report these emissions.
6.2
Impediments to Increased Advanced Metering and EIS
Installation
Awareness and Cost – Advanced metering is not often considered as a basic part of new
construction or major renovation. The cost of advanced metering/EIS packages is sometimes
hard to estimate with certainty, and potential benefits are not well understood. A common savings
level 39 for advanced metering and an EIS in commercial buildings is a minimum of 5%. As
building size decreases, there is less data regarding the expected savings percentage. Marketplace
separations between those who would purchase the equipment and those who would benefit from
it further complicate decision making. Those separations may include developer/future owner,
owner/tenant or owner/energy incentive program manager.
Shortage of Trained Personnel – Key performance indicators and benchmarking tools can be
automated to some degree, but the necessity for human interaction to monitor and interpret results
can never be eliminated. Smaller buildings tend to use fixed service contracts with HVAC
technicians to reduce costs. These technicians are typically not trained in using energy
consumption and interval data to make assessments.
38
Demand Response Enabling Technologies for Small-Medium Businesses, Prepared by Lockheed Martin
for Southern California Edison, April 2006
39
Various interviews
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7 Conclusions and Recommendations
Advanced metering and EIS hardware is well developed, and current technology is well suited to
basic performance monitoring and benchmarking. The technology’s ultimate objective is more
accessible and usable feedback on building energy performance for owners, program sponsors
and policymakers. In light of the above discussion of drivers and impediments, the following
actions could increase the potential for achieving that objective:
•
Efficiency programs should consider automated metering options as a way to acquire
better and faster feedback on program results, while also providing the benefit of better
feedback to participants. Advanced metering and EIS equipment costs may decrease with
increased volumes, and general requirements or bulk purchasing for a widely used
program could provide an opportunity to reduce costs. The USGBC has announced its
intention to require performance data for LEED-NC buildings after 2010. Similar
requirements in efficiency programs, or in other state and local codes, would provide
similar benefits.
•
National benchmarking tools provide a simple number assessing building performance
relative to like-type buildings. Advanced metering and EIS provide opportunity to
enhance benchmarking immediacy and the potential to allow for expanded detail in
Benchmarking and Baselining.
•
A policy at the national level standardizing the cost to upgrade utility meters to pulse
output would provide clarity regarding costs to owners and allow for local interval
measurement of fuels without requiring owners to maintain the meters or the utility to
provide data from a secure database.
•
A simple and convenient software tool for the acquisition and management of data is
needed to permit smaller building owners in particular to achieve the benefits of feedback
from advanced metering and EIS.
•
EIS hardware is capable of multiple measurements within a facility that can support the
isolation of energy systems to make more advanced forms of energy analysis, such as
Energy Infometrics and system-level benchmarking, possible. EPA may want to develop
tools to support certification of buildings based on these enhanced methods.
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References
Motegi et al, Web-Based Energy Information systems for Energy Management and Demand
Response, LBNL-52510, CEC PIER Project, April 2003
Motegi, Piette, Web-Based Energy Information Systems for Large Commercial Buildings, LBNL4997, May 2002, Lawrence Berkeley National Labs
Sullivan, Hunt, Pugh, Metering Best Practices, Federal Energy Management Program, US DOE,
October 2007, page 2.1
Bareley, Deru, Pless, Torcellini, Procedure for Measuring and Reporting Commercial Building
Energy Performance, NREL TP-550-38601, October 2005
Gilespie et. al, A Specification for Performance Monitoring, Specifications Guide Version 1,
LBNL, March 2007.
Advanced Utility Metering, Architectural Energy Corporation, NREL SR-710-3359, 2003
Assessment of Demand Response and Advanced Metering, FERC, December 2008
C&I 2008 Energy Efficiency Program Summary - Whole Building Approaches, CEE website,
2008
Energy Sources, Number of Buildings for Non-Mall Buildings, 2003, Commercial Buildings
Energy Consumption Survey (CBECS), Table B22, US DOE, 2006
Kiliccote, Piette, Advanced Control Technologies and Strategies Linking Demand Response and
Energy Efficiency, ICEBO Conference Paper, September 2005
Cisco Acquires Richards-Zeta Building Intelligence, Inc., press release, January 27, 2009
Johnson Controls Acquires Software company Gridlogix, press release, October 20, 2008
Erpelding, Ultra-Efficient, All Variable Speed Chiller Plants, A Green Imperative, National
Conference on Building Commissioning, April 2008
Demand Response Enabling Technologies for Small-Medium Businesses, Prepared by Lockheed
Martin for Southern California Edison, April 2006
Energy Star instructions for automated data loading, www.energystar.gov
Website: www.automatedbuildings.com
Seryak, Applying State-of-the-Art Analysis to Utility Billing Data, Presentation to Ohio Board of
Regents, Go Sustainable Energy, April 2006
Towards a Framework for Reporting the Energy Use of Buildings and Associated Emissions,
Presentation to Lawrence Berkeley National Labs, April 2008
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Advanced Metering and Energy Information Systems
Google website: http://www.google.org/powermeter/, as of 3/2009
Criscione, What’s Working with Existing Building Commissioning Programs, E-Source, ERDPF-23, 2008
Continuous Commissioning Guidebook for Federal Energy Managers, Prepared for FEMP by
Energy Systems Laboratory and University of Nebraska, US DOE, October 2002
Turner, C. and Frankel, F., 2008, Energy Performance of LEED New Construction Buildings,
NBI Final Report to USGBC.
Commercial Buildings Energy Consumption Survey (CBECS), Tables C.4, B.22, US DOE, 2003
Interviews
EnergyICT, Northwrite, Inc., Powermand, Trendpoint, Obvius, Veris, Cimetrics, GridLogix,
Automated Energy, E-Source, Lucid, Green Touch Screen, SBW Partners, Heschong Mahone
Group, EPA, RLW Analytics, Mad Dash, Inc., NHT Technologies, Energaurd, Portland General
Electric, BC Hydro, Puget Sound Energy, We Energies, Oncor.
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Appendix A Advanced Metering, EIS, and Service
Vendors
Basic Owner-Installed EIS Vendors
Company
Energy ICT
Obvius
Onset Computer
Veris Industries
E-Mon
Powermand
NH Technologies
Northwrite
Itron
Innovonics
Website
www.energyict.com
www.obvius.com
www.onsetcomp.com
www.veris.com
www.e-mon.com
www.powermand.com
www.newhorizontech.com
www.northwrite.com
www.itron.com
www.innovonics.com
Additional Advanced Metering Vendors
Company
Schneider/Square D/
Power Logic
Itron
GE
Siemens
Various
Website
www.powerlogic.com
www.itron.com
http://www.gepower.com/prod_serv/products/metering/en/index.
htm
http://www2.sea.siemens.com/
www.powermeterstore.com
Integrated Platform (Middleware) Vendors
Company
Website
www.cimetrics.com
www.gridlogix.com
www.wonderware.com
Cimetrics
GridLogix (now Johnson Controls)
Wonderware
Richards-Zeta Building Intelligence
(now Cisco)
Tridium
www.richards-zeta.com
www.tridium.com
Third-Party Software Tools
Software Name
EnergyCAP
Metrix
Utility Manager Pro
Energy Profiler Online
Facility IQ
Enterprise Energy
Management Suite
Energy Watch
Pulse Energy
Company
Abraxas
Abraxas
Utility Management Services
ABB
Advantage IQ
Itron
Ei3
Small Energy Group
New Buildings Institute
Website
www.abraxas.com
www.abraxas.com
www.utilityaccounting.com
n/a
www.advantageiq.com
www.itron.com
www.ei3.com
www.smallenergy.com
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Advanced Metering and Energy Information Systems
Energy Monitoring Service Providers:
Company
Mad Dash
Enovity
NH Technologies
EnerNOC
Small Energy Group
Legacy Energy Group
Go Sustainable Energy
Energy Advantage
Professional Systems
Development
Website
www.maddash.com
www.enovity.com
www.newhorizontech.com
www.enernoc.com
www.smallenergy.com
www.legacyenergy.com
www.gosustainableenergy.com
www.energyadvantage.com
www.psdsystems.com
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Appendix B Glossary
Advanced Meter – A meter that measures electrical, gas, or water usage at short intervals (e.g.
15 minutes, one hour), with data typically retrieved frequently by a remote system for monitoring
purposes. The meter is connected to an acquisition system that reads the meter at the desired
frequency or process the regular stream of data coming from the meter.
Advanced Metering Infrastructure (AMI) – A method of managing energy use information for
a utility where advanced meters are enabled with one-way or two-way communications to
automate the retrieval of interval data from each meter. The utility that has an AMI system often
makes interval data and a basic software tool available to the customer through a web portal.
Alternating Current (AC) – A type of electric distribution typified by a wave of alternating
polarity. Used for all normal building power distribution.
ASHRAE – American Society of Heating, Refrigerating and Air-Conditioning Engineers
Automated Meter Reading (AMR) – An earlier form of AMI that automated one-way meter
reading and often provides interval data similar to an AMI system.
Application Service Provider (ASP) – A business that provides computer-based services to
customers over a network.
Building Automation System (BAS) – A control system comprised of meters, sensors, and
actuators that operates building equipment to maintain space temperatures and lighting schedules.
British Thermal Unit (BTU) – A unit of energy or heat content commonly accounted in units of
the therm representing 100,000 BTU. One kWh is equivalent to 3414 BTU.
Commercial Building Energy Consumption Survey (CBECS) – A quadrennial survey of the
energy use and building characteristics of the existing national building stock, performed by
DOE’s Energy Information Agency.
Gateway Communications Service – The method for transmitting data from the Gateway to the
Remote Database.
Current Transformer (CT) – A device placed on an electrical wire to measure the current.
Data Acquisition System (DAS) – A generic term for the method that an EIS uses to collect data
from multiple meters and transmit it to the Gateway. Often combined in the same package as the
Gateway.
DAS/Gateway – A combined unit that houses both the functions of the DAS and the Gateway.
Domestic Hot Water (DHW) – The heated water used for bathrooms and kitchens.
Electric Utility – Any entity that generates, transmits, or distributes electricity and recovers the
cost of its generation, transmission or distribution assets and operations, either directly or
indirectly, through cost-based rates set by a separate regulatory authority (e.g., State Public
Service Commission), or is owned by a governmental unit or the consumers that the entity
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serves. Examples of these entities include: investor-owned entities, public power districts, public
utility districts, municipalities, rural electric cooperatives, and State and Federal agencies.
Energy Informatics – Extracting useful information from energy data sets
Energy Information System (EIS) – Software, data acquisition hardware, and communications
systems administered by a company, partnership, or collective to provide energy information to
commercial building energy manager, facility managers, financial managers and electric utilities.
(Motegi et al 2003)
Energy Monitoring Service Provider – An entity that uses EIS data to make reports and provide
guidance to a building owner for a regular fee or arranged service contract. Also called, Energy
service provider.
Energy Signatures – A term from energy informatics referring to a graphical representation of
building’s historical energy performance data that has been normalized by multiple variables.
Energy Use Intensity (EUI) – A performance metric used to normalize energy use between
different buildings. Found by dividing energy use for a period of time (typically one year) by the
total square footage of the building.
Gateway – A piece of hardware that transfers DAS data to the remote database.
Degree-Days (DD) – A metric for weather-normalizing energy usage that represents the
deviation of the average temperature from the DD base temperature, often 65
Integration Platform - A combination of hardware and software used to augment a BAS to
gather data in a database and apply analysis tools.
Inverse Modeling – A method of creating a mathematical model for building energy
performance using empirical performance data and basic knowledge of the building physical
attributes.
Interval Data – Data recorded by an advanced meter and stored as a measurement with a time
stamp. Often the interval is one hour or less between measurements.
Key Performance Indicator (KPI) – A ratio of two or more quantities used to assess the
continuing performance of a building, system or piece of equipment.
Meter Interface – A device that converts a meter output, such as a pulse output, into a signal for
a DAS.
Middleware – Another name for an integration platform. A combination of hardware and
software used to augment a BAS to gather data in a database and apply analysis tools.
Pulse Output – An output signal commonly found in metering where an electrical pulse, or
contact closure, indicates a certain quantity of the measured substance has passed the meter. By
measuring the number of pulses and the time they occur both the total amount and the rate of
change can be determined.
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Pulse Output Upgrade – When a utility replaces the utility service meter in a facility so that
there is a pulse output that the owner may use to monitor energy use.
Phase – A component of the electrical service that can be monitored using a CT.
Portfolio Manager – The EPA’s tool for energy benchmarking of buildings.
Remote Database – Any data storage database located on the web used to house EIS data.
Settlement - The process of financial settlement for products and services purchased and sold.
Each settlement involves a price and quantity. For energy distribution the electric and gas utility
must install the settlement meter that is used to determine the charges for a customer.
Site Energy – A method of energy accounting where only energy consumed at the site is
“counted” in the evaluation of the building as opposed to
Source Energy – A method of energy accounting where the energy consumed by a building is
modified to account for all energy required to provide the service from the power plant or gas
well, through distribution, to the final end use.
Time Series Data – Equivalent to interval data.
Weather Normalization – A method of adjusting for weather variations using heating or cooling
degree days when evaluating a building’s energy performance.
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