Town of Canton
Street Light Energy Efficiency Improvement
Options
Prepared by
LightSmart Energy Consulting
July 2015
For
Table Of Contents
Background..............................................2
Discussion...............................................2
Definitions...............................................3
Existing High Pressure Sodium Lights.........................4
Induction Technology......................................4
LED Technology..........................................5
Cost/Savings Analysis..................................... 5
Table 1. Multi Wattage Streets............................................................................................................. 6
Table 2. Options Assuming $.25/kWh Incentive..................................................................................9
Table 3. Options Assuming $.035/kWh Incentive..............................................................................10
Maintenance Savings..................................... 10
Financing...............................................11
Table 4. Budget Savings Estimates 10-yr Lease @3%.......................................................................11
Procurement Strategy..................................... 11
Network Options.........................................13
Conclusions.............................................13
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Background
The Town Canton acquired its streetlights from NSTAR in 2005. The system consists of 1985
streetlights. In connection with the acquisition the Town completed the conversion of 246 existing
fixtures from mercury vapor and incandescent to the more energy efficient HPS lighting. Included were
some HPS wattage adjustments to make the system more uniform. This project cost the Town $39,598.62
and NSTAR provided a incentive of $21,163.00 for a net cost of $18,435.62 and it resulted in an annual
savings of $12,709.20. This report will examine estimated costs and savings associated with a complete
conversion of the system to LED lights and consider several options.
1. Conversion of existing lights to equivalent LED lamp.
2. Conversion of the existing system to LED light source with field adjustability
3. Conversion of the existing system to LED technology with internal adjustability and control
ready
4. Conversion of the system to LED with full up controls
In addition it will review the procurement options and the pros and cons of each approach.
Discussion
All street lighting in service today uses high intensity discharge, HID, lamps including high-pressure
sodium, HPS, mercury vapor, MV, and metal halide, MH as the light source. Some very limited numbers
of incandescent lamps are still in service in New England. Mercury vapor was banned in 20081 and may
no longer be installed as a lamp source and the ballasts that support MV lamps may not be produced or
imported. LED roadway lighting first appeared in 2000 but at the time was very expensive and its energy
efficiency was only marginally better than the HID fixtures it was intended to replace. However in the
past two years the cost of a replacement LED fixture for the most common HID wattage fixtures has
dropped dramatically and the energy efficiency of LED fixtures exceeds the HID fixture by more than
50%2. As a result these conversion projects are much more financially attractive. The other issue has
been the resistance of the utilities to adopt tariffs that would support LED lights. Prior to 2011 year the
New England utilities were not allowing either induction or LED technology with the exception of
NSTAR. These are new to street lighting applications and there is little history on their performance over
time and the frequency of failure. As such the utilities were not able to develop a tariff rate that would
reliably protect their investors and insure profitability. However, NSTAR started and the other utilities
have followed allowing their use for communities that own their lights. In addition they contribute to
energy conservation and the ability of the utilities to meet their reduction mandates. Consequently they
are offering incentives to communities to make the change. NSTAR has indicated they would offer an
incentive for an LED conversion of at least $.25 per kWh saved thru their custom application process. In
addition the Town has the possibility of having this increased to $.35 per kWh saved if they complete the
work by sometime in August 2015. In order to meet that timeline the Town will need to follow a very
aggressive schedule.
The assumed energy rate is $.14096 per kWh, which was derived from NSTAR's distribution tariff rate
for customer owned lights of $.04931 and contract supply rate of $.08891 which is the current contract
price with Suez. NSTAR uses 4200 hours of operation per year broken down into monthly amounts
based on average dusk to dawn times. Street lights are not metered.
1
The 2006 Energy Policy Act banned the importation or manufacture of MV ballast effective 1 January 2008 which will
eventually cause all MV lamps to be replaced with an alternative lamp source.
2 Note there is a difference in lamp efficiency and fixture efficiency. HID fixtures have upwards to 35% internal losses while
most LED fixtures deliver more than 96% of the LED output to the roadway. In addition HID fixtures suffer additional losses
from the affects of time-dirt lumen depreciation.
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George A. Woodbury July 2015
Definitions
Color Rendering-The ability of a light to correctly render a standard color palate as compared to a
standard source light. While it is theoretically to have a color rendering of above 100 generally all lights
sources fall within the 0 to 100 range with 100 being true colors. HPS is rated at 25, low pressure sodium
at zero, metal halide can range from 65 to 92, induction at 82-84 and LED is typically 74 to 80. Studies
have shown a shift to higher color rendering sources improves nighttime visibility, assists with crime
prevention and is more appealing to the public.
Correlated Color Temperature- The apparent color of a light source measured in degrees Kelvin, °K As
the color temperature of a light increases it shifts from red to blue. BMW headlights are in the 7000°K
Chart from the web site of a California company, Seesmart Inc.
Efficacy-This is a measure of the amount of lumens produced per watt of applied power. Keep in mind
that there is a difference between fixture efficacy and lamp efficacy. As an example the 100 watt HPS
lamp when taking into account the lamp and the ballast uses 121 watts and produces approximately 9600
lumens. But once placed inside a fixture the internal losses of the fixture reduce the effective lumens of
the fixture to about 6500 lumens. 3 Each fixture has a certain amount of loss associated with design.
3
Based on DOE Caliper 7 test results. Typical HPS cobra heads lose approximately 35% of their light output due to design while a well designed
LED lamp will emit over 96% of its rated lumens. Additionally in reviewing replacement options the DOE LM79 report provides us
with the actual emitted lumens and distribution pattern for a fixture from an independent lab test.
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George A. Woodbury July 2015
Lumens-a measure of the total output of a light source as measured inside a special sphere.
Foot-candle-The amount of light falling on a surface as compared to the light from a single candle one
foot from the measuring device or a lumen per square foot.
Existing High Pressure Sodium Lights
HPS (High-pressure Sodium) is the lamp of choice for the utilities. It is very energy efficient and a low
cost option. Typical HPS lamps have an efficacy 96 lumens per watt with a fixture efficacy of 54 lumens
per watt of power. Its primary drawback is that it is a very poor color rendering source, rated at 25 and so
requires higher lumen levels to provide the same level of perceived brightness and visual clarity.
Additionally, as noted above, the typical fixture loses approximately 35% of the lamp output due to
fixture inefficiency and this is compounded over time over time with fixture age. Average lamp life for
HPS is 24,000 hours or six years.
Induction Technology
Today there is widespread interest in both induction and LED technology. Some discussion of induction
technology is provided here. However, in the past two to three years we have seen LED technology
surpass induction technology in efficiency, performance and savings. Induction technology is a variant of
fluorescent technology that is electrodeless and as such has extraordinary lamp life - 80,000 to 100,000
hours. It produces a high color rendering source, roughly 82 verses HPS of 25 that is perceived by people
as brighter because of improved light output in the spectrum of light that aids night vision.
Induction lighting is not a new technology but rather one that had not received a lot of interest previously
because of its relatively high cost and the low cost of energy. Early on it found application in locations
that were difficult to access or very expensive to access where long life lamps saved considerable
maintenance expense. However given the much higher energy rates today, the higher labor rates and the
fact that the cost of these fixtures has come down some, they are a useful alternative in certain
applications. Induction fixtures are nearly identical to HPS in overall efficiency but because of the
improved night-time visibility offered by a full color rendering source and the perception of the human
eye, we find we can reduce lumen levels by roughly 35% and the light level is perceived as the same.
Three to four years ago higher energy costs, increased maintenance costs and a lower fixture cost relative
to LED lighting created a short-term market for induction streetlight applications. PSE&G in New Jersey
installed approximately 140,000 induction lights in their service territory in 2010. The potential savings
over HPS lights from induction lighting is about (35-40%). Although failure rates are generally low, we
have found induction lamps to have higher initial failures than LED's. One application where Induction
may have a slight edge over LED is for decorative Post Top lighting, which is why it is presented here. In
2010 three of the 150 watt metal halide decorative lights on route 109 in the vicinity of the Canton Fire
Station were converted to 80w induction light sources using a kit designed and built by the author of this
report. These are still in service and difficult to distinguish from the other fixtures. The lower glare levels
and higher color rendering can be considered enough to outweigh LED’s better efficiency rates in certain
applications. LED retrofit kits for decorative lights continue to be quite expensive from most
manufacturers but a recent product release by Cree is changing this.
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LED Technology
LED technology is the choice for roadway and many other lighting applications today as it can provide a
fifty to sixty-five per cent energy savings and like induction lighting offers extraordinary long life
(100,000 hours) greatly reducing maintenance costs.
LED technology is not new but in fact has been used since the early 1960s. The early LED’s were limited
to red and typically as indicator lights. They began appearing in traffic signals in the late 1980’s. As the
science progressed we began to see other colors than red and some early efforts to mimic white light
using fixtures with combination or red green blue and yellow LED chips. In the late 90’s using nano
technology and either ultraviolet or long wavelength blue LED’s in combination with phosphors we were
able to produce white light. These early LED’s were very expensive and not very energy efficient. The
overall efficiency of the LED lamp continues to improve rapidly. Typical efficacy is 94 to 115 lumens per
watt as compared to HPS at 54 fixture lumens per watt. Beta, the leading US LED chip manufacturer has
just announced their newest LED chip at over 124 lumens per watt. Additionally we have seen the cost of
LED technology drop fairly dramatically making it far more attractive. Just three years ago the average
cost of a 250w HPS replacement LED fixture could cost over $650. Today that same replacement costs
less than half at $286.
The color rendering of LED lights is slightly lower compared to induction, 74 verses 82. We have found
that a color temperature with an acceptable performance level for LED is around 4300K. There are
versions available in the 3000K range but to get the warmer color temperature they sacrifice energy
efficiency and lamp life. The 3000K color temperature is generally more appealing for decorative down
town areas which would suggest the induction lamp. However, the new Cree DPT solution is also a
3000K lamp and is about the same price or slightly cheaper than the induction kit. The question will be
our ability to adapt it to the existing decorative fixtures in Canton. Furthermore, individual LEDs within
an LED array of a streetlight fixture are directional and designed to provide a wider more uniform
dispersion of light. LED fixtures are superior in areas where street lights are wider apart. LED lights life
expectancy is sensitive to high temperature. New England is an exceptional location for their use. Hotter
areas such as Phoenix with night-time temperatures routinely above 80 degrees can shorten the life of the
LED and its drivers. LEDs are unaffected by low temperatures and in cooler climates will actually realize
extended life.
Cost/Savings Analysis
There are a number of political considerations when making a conversion of a community's streetlights.
It is remarkable how little attention is paid by the public until something is changed. It will be important
to let the public know what and why the Town is making the change. Just as important is the decision if
dollars are limited is which lights to do first. There is always the possibility one neighborhood will
complain because the other neighborhood got the new lights first. In both Watertown and Arlington the
community chose to do the denser populated neighborhoods first. Other communities such as Fairhaven
chose to tackle the main thoroughfares first as they generate the most savings and then to use the savings
for follow-on phases of work. This approach also has the advantage of wider exposure to the new
technology and improved lighting in the business areas helping to improve the attractiveness of these
areas. Lastly it is important the Town leadership and in particular the political leaders are educated so
that they can effectively address constituent questions and concerns.
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IESNA (Illuminating Engineering Society of North America) provides their recommended lighting levels
in their publication RP-8 Roadway Lighting Guide. The level of recommended lighting is based on the
class of roadway and the pedestrian conflict levels. Generally all arterials would be lit at the same levels
unless they had differing pedestrian activity levels. Roadway's can change from one class of use to
another and the level of activity can vary widely all of which would impact on the recommended lighting
levels. Included in the Appendices is a list of these streets and the distribution of existing wattages. The
project to eliminate the older mercury and incandescent lights and make the system more uniform in the
Town back in 2006 was successful at eliminating the older mercury vapor lamps and reducing some
wattages to make the system more uniform and efficient. There may still be additional adjustments we
might consider as part of this project. We can see from the table below that there are a few cases. A
visual inspection should be made to determine the correct wattage replacements based on site conditions
and activity levels.
Table 1. Multi Wattage Streets
Street
ALGONQUIN
BAILEY
BELCHER
BOLIVAR
CENTURY
CHAPEL
CHAPMAN
CHEROKEE
CURTIS
ELM
JACKSON
KINGS
LAWRENCE
LEGION
MEADOWS
MOHAWK
OAK
OAKDALE
OSAGE
PALMER
PECUNIT
PINEDALE
PLEASANT
RANDOLPH
REBECCA
REVERE
TURNPIKE
WALNUT KNOLL
WALPOLE
WASHINGTON
WHITMAN
YORK
2150
9
1
3
2
2
17
11
8
3
1
9
5
11
2
1
3
1
13
1
3
4000
2
9
1
23
2
1
24
1
10
3
4
10
4
1
3
1
4
1
2
4
6
2
57
36
5
29
2
4
26
15
60
LUMENS
9500
16000
2 1 5 27 93
11
2 25000
45000
1
5
2
1
2
1
1
1
2
1
1
18
2
19
2
Grand Total
12
10
2
30
5
3
28
3
12
20
5
21
12
4
4
10
9
12
4
6
9
3
78
65
6
30
39
7
27
156
4
62
A review of the inventory also shows the Town is paying for lights located on Blue Hill River Road
which may belong to the State Department of Conservation and Recreation and may or may not belong on
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
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the Town’s bill. There are also two lights on Deady Ave. that are on a separate account. If there is no
reason for this then we might want to incorporate them into the main account and eliminate the fixed
billing charge on this account.
This report will recommend LED lights consistent with the lights currently in place except where it is
determined a higher or lower light level is appropriate. We will review the lights that are inconsistent with
the other lights on the street to determine if they warrant change. These reviews typically result in some
lights on arterial roadways having their wattages increased but overall more lights are reduced in wattage
because the largest majority of the inconsistent lights are higher wattage fixtures on neighborhood streets
that can be reduced to be consistent with the residential lighting recommendations.
LED Options -LED technology opens up a variety of options. HID lighting can be dimmed but to do so
requires a special ballast which is both expensive and prone to failure due to line voltage variations. The
utilities have seldom invested in this capability because of the cost and there was little benefit to them to
do so.
1. Internal adjustability-LED lights can be delivered that have the ability to operate at a variety of
settings similar to a three-way bulb. Inside the fixture there are multiple taps allowing the fixture
to be set a different light levels. This permits easy adjustment if a community decides to respond
to complaints or special conditions. It also allows the light to be used in a variety of locations
simplifying replacement spares. The number of settings can very from three to nine depending on
the manufacturer.
2. Dimming-There are photo controls which would provide for timed dimming or even turn a light
off after a certain period of operation on a fixed schedule. This allows part night dimming to save
money during times when activity levels are minimal.
3. Intelligent controls-There are a variety of companies that produce an intelligent controls that are
remotely operated. Communication with these controls or nodes is typically either hard wiredover the line communication using the line feeds to the streetlight or wireless. The over the wire
technology is unlikely to be used to any extent in the US because of the nature of the line feeds to
the streetlights. This method cannot bridge transformers and in the US there are too few lights on
a single transformer and this drives up the cost of such a system to make in uneconomical. The
wireless systems vary widely in design and operating frequency. They typically use either a point
to point communication system or a mesh network. In a point to point systems each node
communicates with a collector device or gateway that is connected to the internet either through a
direct connection to a fiber-optic backbone or wirelessly back to a single connect point to the
internet. The nodes do not talk to each other. In a mesh network the nodes can communicate
with each other and relay information back to a gateway which then is either connected to the
internet or wirelessly communicates to connect point. Different companies use different
frequencies but most fall in the public frequencies such as 2.4 GHz, 500 MHz or 900MHz
frequencies. A small number license a frequency from the FCC for their exclusive use. Each
company will tout the advantages of their approach. The trade-off is that higher frequencies have
shorter ranges and less penetration but can transmit higher data levels. The lower frequencies
have greater range and penetration but lower data rates. What is important in choosing the right
carrier is the evolving interoperability standards both nationally and internationally and the ability
to expand the use of the network for other municipal needs.
There are only a few companies that use the same communication device in electric meters, water
meters and streetlight nodes and can also be linked to traffic signals and other applications. We
have selected Silver Springs Networks as our preferred network provider not only because they
are closely tracking the developing standards but because their communication system is being
used in over 17 million electric meters and they will be doing the largest streetlight application in
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
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the country with over 500,000 being installed in Florida Power and Lights streetlight system. In
addition they are doing a major project in Paris to link traffic signals through their network.
Controls also have a meter chip embedded in them so each node will measure the energy used
and report this back to the client. This opens the possibility for unlimited dimming or operating
parameters for each light or group of lights. An individual light could be flashed outside a house
where there is an emergency to help guide response crews. Lights could be flashed in sequence to
aid in an emergency evacuation. Other devices could be tapped into the light circuit and the
utility would know the energy consumed. Lights could have sensors to detect activity and adjust
light levels accordingly and so forth. In addition the communication network could be used to
read water meters and other devices and transmit that data back to those who need it. The
streetlights become an integral part of a smart city and the possibilities endless, much like the
smart phone and all the apps that can be used.
There are a number of LED fixture manufacturers that have been in the business long enough, have a
significant number of their products in service demonstrating the reliability of their LED’s and have the
financial strength to provide assurance to the Town they will be around to stand behind their product for
the duration of the ten year warranty. These include GE, Philips, Leotek, Beta (Cree)4, Ledway and
Acuity to name a few. Leotek and Beta have generally been the leaders in most large installations
followed closely by Acuity and GE. All are excellent fixtures with some variation in design, options and
cost. Cost estimates are based on previous bids and reflect a procurement approach that purchases the
equipment through the approved State vendors and labor to install through a formal bid process. This has
proven to provide the lowest total cost. Alternative procurement strategies and their pros and cons will be
discussed later.
As noted in the beginning we will look at three different options for the Town.
1. Conversion of existing lights to equivalent LED lamp. This simply replaces the existing fixture
with an LED fixture that will provide the equivalent lighting for that location. These lights will
not be adjustable in the field and will use a conventional long life photocell. They would allow
the future use of preprogrammed photocells for part night dimming or operation. Keep in mind
NSTAR does not currently have a tariff for part night dimming.
2. Conversion of the existing system to LED technology with internal adjustability and control
ready. This is a variant of 2 above in that the fixture would be set up control ready and with the
internal adjustability. This would allow the Town the option of not investing in the controls
today but they could be added in the future. There are both advantages and disadvantages to this
approach. The advantages are a.) Lower initial capital investment resulting in greater immediate
savings; b.) The future cost of controls is likely to come down and the standards will be more
mature and c.) NSTAR may have in place the supporting tariffs allowing the Town to benefit
financially from dimming or part night operation. a.) Interest rates will be higher; b.) There will
be an added cost to revisit each light to install the control nodes; and c.) The Town will have less
interest in pushing NSTAR to develop the needed tariffs and could not take advantage of the
other opportunities the controls offer.
3. Conversion of the system to LED with full up controls. This approach will be the most
expensive. It would provide the Town with the ability to use the system for a multitude of
purposes even if they did not provide a financial savings on the streetlight bill.
The table below outlines the three options with projected costs for each and assumes a minimum incentive
of $.25 per kWh saved or a higher $.35 per kWh saved based on the belief NSTAR would provide higher
incentives for a system with controls. Option four with the controls should qualify for even higher
4
Cree acquired Beta three years ago. Cree is the leading LED chip manufacturer in the US.
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
`9
incentives because of the dimming capability. In addition using the dimming capability between
midnight and five am will increase the energy savings by 21%. This analysis assumes an energy cost of
$.08891 for supply costs based on the most recent contract with Suez and $.050205 for delivery costs as
previously mentioned. The savings assume the project is fully funded outside of the street lighting budget
so the savings on the following two tables do not account for project financing costs..
Table 2. Options Assuming $.25/kWh Incentive
Fixtures
Labor
Training
Installation of Gateways
Project Design
Travel
Network Deployment
Long Life Photocells
Total Project Cost
Incentive
Net Project Costs
Annual Total Budget
Energy/Maintenance Savings
ROI years
Simple LED
$235,901.10
$100,500.00
N/A
N/A
N/A
$3,000.00
N/A
$36,180.00
$375,581.10
$69,840.75
$305,740.35
Field
Adjustable
$299,595.14
$100,500.00
N/A
N/A
N/A
$3,000.00
N/A
$36,180.00
$439,275.14
$82,308.45
$356,966.69
Control Ready
$264,381.14
$100,500.00
N/A
N/A
N/A
$3,000.00
N/A
$36,180.00
$404,061.14
$82,693.95
$321,367.19
Complete
w/Controls
$525,681.14
$120,600.00
$12,500.00
$12,000.00
$5,250.00
$5,000.00
N/A
N/A
$681,031.14
$93,396.71
$587,634.43
$58,529.72
5.17
$65,559.51
5.40
$65,776.87
4.84
$63,876.66
8.97
There are a number of costs associated with the control system that warrant a brief explanation. The
Town would procure and own the control nodes on each light. Silver Spring Networks would own the
gateways and any required relay devices that communicated with the nodes and connected to the network
servers. Silver Spring Networks, SSN operating through their Agreement with their local agent would be
responsible for the replacement of any network hardware. The labor would be performed by the Town’s
street lighting maintenance service provider at the Town’s expense. SSN would maintain the server, and
provide the needed software as a service and ensure reliable access and required updates or upgrades to
the system to ensure its reliability. They charge an annual fee for this service of $6.95 per light or in the
case of Canton $13,969.00 annually. The closest analogy is cell phone service. Once you own the phone
you have to pay an annual subscriber fee. The advantage of this approach is the experts are keeping the
system reliable and current with all needed security protections and the Town always has someone to turn
to for assistance or upgrades to their system to integrate other capabilities. The disadvantage is the
continuing fees. In addition they will complete the design of the network to identify the number of
required gateways and relays needed to communicate with every node reliably. Once the system is up
they will send personnel to Canton to install the required software on the Towns computers and provide
training on the use of the software and the system operation. Table 3 below illustrates the financing
assuming a $.35 per kWh save incentive. There is a possibility if the Town commits to completing the
work by 1 December we could get an increase in the incentive. Generally I recommend that we include in
the financing the first three years of the network fees to give us time to get EVERSOURCE to develop a
supporting tariff. This approach helps keep the budget flat because by the time the fees become due the
Town can benefit from dimming the lights after certain hours nearly offsetting the fees. In addition based
on the amount of deployment in the New England area these costs do decrease with increased volume.
Table 3. Options Assuming $.035/kWh Incentive
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George A. Woodbury July 2015
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Fixtures
Labor
Training
Installation of Gateways
Project Design
Travel
Network Deployment
Long Life Photocells
Totals
Incentive
Net Project Cost
Annual Total Budget
Energy/Maintenance Savings
ROI years
Simple LED
$235,901.10
$100,500.00
N/A
N/A
N/A
$3,000.00
N/A
$36,180.00
$375,581.10
$97,777.05
$277,804.05
Field
Adjustable
$299,595.14
$100,500.00
N/A
N/A
N/A
$3,000.00
N/A
$36,180.00
$439,275.14
$115,231.83
$324,043.31
Control
Ready
$264,381.14
$100,500.00
N/A
N/A
N/A
$3,000.00
N/A
$36,180.00
$404,061.14
$115,771.53
$288,289.61
Complete
w/Controls
$525,681.14
$120,600.00
$12,500.00
$12,000.00
$5,250.00
$5,000.00
N/A
N/A
$681,031.14
$130,755.40
$550,275.74
$58,529.72
4.70
$65,559.51
4.90
$65,776.87
4.34
$63,876.66
8.38
Maintenance Savings
The manufacturers of both LED and Induction streetlights claim life expectancies of 100,000 hours or 23
years (4200 operating hours per year). While some lamps may last that long there is no long-term data or
predictions on system life expectancies. Never-the-less manufacturers are offering ten-year warranties.
In addition to the fixture there is also the photocell, which is typically rated at 5000 cycles mean time to
failure or about 13.7 years. Mean time to failure is the point at which 50% have failed. Long life
photocells are rated at twenty years or more. Intelligent controls right now have a five-year warranty. So
in spite of claims of zero maintenance we know that to be untrue. There are still labor expenses
associated with replacing failed units plus handling costs to secure replacements as well as other
non-warranty repairs. Thus far the reported failures of the LED lights in the large project such as Los
Angeles who has installed 140,000 LED lights are in the .2% range-198 of 98,000 installed5. In
Fairhaven where we have installed over 1400 LED lights over four years we have had four fail. Induction
lighting has had a rather varied performance history. Many large installations such as Sun City AZ have
had virtually no failures and yet in Lexington we experienced over 30% failure rates and Sylvania
recalled all of their 40watt ballasts. New Jersey has also experienced higher than expected early failure
rates but then they used the same products deployed in Lexington. It appears that the induction lights
produced by Kumho have been a better performer so it will be important if we opt to use induction in the
decorative lights to use their product.
Currently the maintenance contract for Canton’s is $.89 per light per month plus any extra work. This is a
flat fee approach and is paid regardless of the number of actual repairs. Typical HPS system failure rates
are 18-20% per year. The $.89 covers most routine repairs-bulbs, photocells, starters, ballasts, tree
trimming, cleaning, and fixture replacement. It does not cover knockdowns, mast arm replacement,
rewiring a fixture, underground failures, relocation of mast arms when a pole is replaced by NSTAR or
painting of decorative fixtures. These are classified as extra work and they will occur whether the light is
an LED or an HPS lamp. Canton has 2010 lights so their current cost for routine work is approximately
$21,500 plus some costs for unexpected work. I have assumed $2,000 for the extra work so a total
current annual maintenance of $23,466. This contract should be adjusted to become a time and materials
5
Ed Ebrahimian Director of LA Bureau of Streetlighting presentation to the Municipal Solid State Lighting Consortium
workshop Los Angeles April 2012 and published in Forbes magazine January 25, 2013.
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George A. Woodbury July 2015
contract once the LED system is in place. The Town then can expect to see this drop to less than $4,400
per year including the $2000 allowance for extra work.
Financing
Bonding is always an option for Cities and Towns. However bonds carry certain relatively fixed issuance
costs which when considered can add significantly to the overall cost of the money particularly for
amounts of less than several million dollars as is the case here. Additionally bonding rates have seen a
jump in interest rates in the past year due to the number of communities defaulting on loans across the
county.
Alternatively the Town could use a tax exempt lease arrangement to finance the project. Current ten-year
tax exempt lease rates are around three percent. These programs are designed to pay the costs using the
savings and can be structured to provide some immediate budget savings by selecting a longer lease
period. The most expensive option has a payback of 8.38 years so a ten-year lease would allow the
project to be completed for slightly less than the existing budget. Lease purchase financing is subject to
annual appropriation and as such in Massachusetts is not considered a debt but rather an operating budget
item. As such it does not affect the Town's debt levy limit or the bond rating. Some communities have
used the lease option as a bridge to a future anticipated bond issuance for some other large project and
paid off the lease once the bond was issued. The table on the following page illustrates a ten-year lease
applied to this project assuming the higher incentives from NSTAR. We would request quotes from as
many as ten financing institutions who are familiar with this type of project and have provided financing
for them in the past to get the best rates. Clearly, if Eversource provides higher incentives then these
numbers will improve. The table below is based on a guaranteed minimum incentive rate and shows the
budget savings net of financing.
Table 4. Budget Savings Estimates 10-yr Lease @3%
Plain LED
Energy Savings
Maintenance Savings
Annual Network Fees
Net Annual Savings
Project cost
Incentive
Net Amount Financed
Annual Finance Costs
@3%
Net Annual Budget
Savings
Field Adjustable
LED
Control Ready
LED
LED
w/Controls
$46,408.80
$19,054.80
N/A$65,463.60
$372,581.10
$115,231.83
$274,804.05
$46,408.80
$19,054.80
N/A
$65,463.60
$436,275.14
$115,771.53
$321,043.31
$46,626.16
$19,054.80
N/A
$65,680.96
$401,061.14
$130,755.40
$285,289.61
$69,772.75
$17,149.32
$(13,969.50)
$72,952.57
$666,281.14
$173,243.91
$535,525.74
$(31,251.26)
$(36,509.68)
$(32,443.70)
$(60,901.04)
$27,278.46
$29,049.83
$33,333.17
$2,975.62
Note: Assumed higher maintenance costs with control system due to its complexity.
Procurement Strategy
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
`12
These conversion projects have generally followed one of two strategies. The MGL 30b low bid
approach or the MGL 25a performance based contract approach. The major difference between the two is
risk.
Low Bid Approach Under MGL 30-39m. Under the low bid approach there are several possible variants.
The first is to bid the installation on a per unit basis that includes the photocell and the LED fixture. The
Town is responsible for completing the design in order to specify the required quantities and types.
Purchasing the LED fixtures and photocells thru the State procurement contract and only bidding the
installation work is the second. The issue here is the Town assumes the administrative burden of
handling the lights and the risk of warranty failures. In the event of a failure the Town would have to
provide the replacement fixture to a contractor and pay the contractor for the change out. The Town
would have to receive the failed unit and send it back to the manufacturer for replacement or coordinate
this through the selected maintenance contractor. Additionally the Town would need to maintain a certain
level of stock so that replacements would not be delayed. The Town could opt for a low bid approach
that included not only the installation but also the LED lights and the photocell as well as a warranty for
repairs provided thru the installer. This is essentially what happens with a performance based contract
approach where the installer takes on the risks but it is of course reflected in the prices. Under this
scenario the Town has no control over the installed product beyond the specifications. Consequently you
could wind up with a poor quality product and the challenge of proving it was not equal to the
specification. Under this approach it is best to limit the bid to the installation work and the time and
materials work needed following installation.
Performance Based Approach Under MGL 25a § 11i. The performance based contract is a RFQ or RFP.
The Town selects a partner based on their qualifications or proposal and works with that partner to
complete the final design and do the installation. The selected company must guarantee the savings and
provide coverage for the warranty period which is typically ten years. As a part of their proposal the
Town could request a project cost estimate and the savings estimate subject to minor changes as the
design is completed. The advantage of the performance based contract if properly written is the risk of
premature failure falls to the awarded company not the Town. Additionally the Town could incorporate
into the contract other miscellaneous repairs such that the selected company would manage all system
repairs during the ten-year warranty period. This would save having to rebid the maintenance service
contract every three years. These companies generally use the tax exempt lease financing approach and
typically provide that as a service to facilitate the project. Finally, a performance based approach
provides a savings guarantee. This may seem attractive but in the case of streetlights, it is totally
unnecessary because the parameters of streetlight billing are fixed. The hours are set and the wattage is
based on the installed fixture wattages. If the wattage is reduced by half, the bill will be reduced by half.
It is not at all like the much more complicated building control systems or variable drive pumps and so
forth where such guarantees are warranted because of the complexity of the variables affecting the
savings. Street lights have only one variable-the wattage of the fixture. There have been five major LED
projects awarded using the performance based approach and those bids show an average increase in costs
of approximately $94-$180 per fixture installed verses the low bid approach. This would increase the full
system conversion costs by more than $100,000.
The question is what are the risks. There are two principal risks. First is getting the right product for the
project. There are a lot of LED streetlight manufacturers but only a handful that have been in business for
any length of time and who have the financial strength and reputation to give the Town assurance they
will be around to back their warranty. Additionally each manufacturer has a slightly different approach to
the photometrics, optics etc. when they design their lights. Basing a product bid on a set of specifications
runs the risk the low bid will not be a product the Town wants or trusts. There are sufficient variations in
designs that one could easily develop a specification that limited the qualifying companies to one or two
but such a bid would be subject to challenge. Certainly, the best solution is to buy through the State bid
which still allows the Town to negotiate price with the approved vendor. If you did not believe you were
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
`13
getting the best price based on what you know about the market, the Town would still have the option of
going out to bid.
The second risk is the premature failure of the fixtures. The cost to send a crew out to replace a failed
fixture would be roughly $110-to $125. The added cost of the performance contract of $100,000 means
over 800 fixtures would have to fail to offset the added cost of a performance contract. Related to this is
the possibility that even a very large company whose fixtures suddenly experienced catastrophic failures
could go bankrupt or the installing company could get out of the streetlight business. When the Town
acquires the lights through a State vendor it becomes very important to select a quality product from a
company with a proven track record and a strong balance sheet. There is no guarantee that even
companies like Honeywell, or Siemens might not abandon their streetlight business. Over time these
fixtures will continue to improve and become less expensive so the cost of replacement will also go down.
The lowest cost approach is the low bid approach to select an installation contractor and then use a State
approved vendor to procure the fixtures thereby ensuring getting the desired products. While this has the
highest risk for the Town, these risks thus far have proven to be minimal in other LED conversion
projects across the country. LED lights seem to be performing as well as promised.
Network Options
Smart Grid is a relatively new term. Many electric and water companies have installed meters that can be
read from a distance with a hand held device. These are called AMR systems. The newer technology is
the AMI system that uses wireless communications to transmit the data across a network eliminating the
need to drive around to get the usage information. Silver Spring Networks is one of the few companies
that is looking to integrate all of these devices through a single network and building as part of its core
business software to accomplish this. Further they are working both with the American National
Standards Institute, ANSI and the international standards group, TALQ to foster interoperability. The
Town has the option of linking their water meters into the mesh network. SSN is working with five of the
major water meter companies, Itron, Mueller, Neptune, Badger, Elster and Sensus. The Town would not
need to replace its meter just the device on top of meter that converts the meter measurements into a
reading. Likewise the same mesh network could be used with traffic signal controllers to synchronize the
traffic signals to improve traffic flow. Air quality and weather data could be transmitted over the
network. It could be used to monitor wastewater flow rates, control devices etc. The options are endless
and only limited by the bandwidth of the network. Where additional bandwidth is needed the system
could be supplemented as needed.
The two potential approaches are to supplement the mesh network at specific points or to build a robust
network throughout the Town and have it support the street light mesh nodes. This latter approach is
being used in Buffalo New York because they have high crime rates and want the ability to install
cameras in the high crime areas quickly and have the flexibility to move them as needed. Some Towns
want to provide WIFI services for their community and this would require the more robust network.
Needless to say such a network is significantly more expensive.
Conclusions
This analysis shows that the Town could, within the existing budget, convert all of their streetlights to
LED technology and a complete control system. The conversion to LED lighting would provide a white
light source that would improve the overall lighting in the Town and based on experience in other
communities be widely approved by the voters. A project of this nature has the opportunity to "rebrand"
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
`14
the Town in a very positive way and provide visible evidence of the cost savings and improvement to the
Town's lighting acquiring their lights has made possible. It also would put Canton on the forefront of the
smart city concept.
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
`15
Appendix 1
Light Distribution
Lumens
Street
ABBEY
ADRIENNE
ALDRICH
ALGONQUIN
ALGONQUIN RD
AMES
ANDREA
ANGELA
ANNA
APPLE BLOSSOM
ASHDALE
AUTUMN
BAILEY
BARBARA
BAYBERRY
BEALS
BEATTY
BEAUMONT
BEAVER BROOK
BELCHER
BEVERLY HILL
BIRCHCROFT
BLACKMAN
BLUE
BOLIVAR
BOSTON
BRETON
BRETTON
BRIAR
BRIDLE
BROOKSIDE
BROOKSWELD
BURKE
BURNS
CALLERY
CAMPANELLI
CANTERBURY
CAPE COD
CAPEN
Street
CAPPER
CAREY
Lights
OFF
3
3
Lights
OFF
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
2150
9
2
1
9
3
3500
4000
1
4
2
3
3
4
4
8
1
3
5
9
5
3
1
3
5
3
1
4
11
23
1
1
5
1
1
5
2
2
1
3
3
4
1
9500
20
16000
25000
2150
3500
4000
5
1
9500
16000
25000
`16
Grand
Total
1
4
2
12
3
4
4
8
1
3
2
5
9
5
3
1
3
5
3
2
4
9
11
23
26
1
1
5
1
3
1
5
2
2
1
3
3
4
1
Grand
Total
5
1
CAREY CIRCLE
CARRIAGE
CARVER
CASEY
CEDAR
CEDAR EXPRESS
CEDARCREST
CEDARCREST RD
CENTRE
CENTURY
CENURY
CHAPEL
CHAPELGATE
CHAPMAN
CHARLES
CHEROKEE
CHESTNUT
CHIEF
CHURCH
CIRCUMFERENTI
CLIFF
CLOVER
COBBLESTONE
COLONIAL
CONCORD
COTTER
COUNTRY
COUNTRY CLUB
CRANE
CROSS
CULLODEN
CURTIS
CYNTHIA
DAN
DEDAHM
DEDHAM
DEVONSHIRE
DEW
DIANA
DINAH
DOWNES
DRAPER
DUNBAR
Street
EAGLE
EDWARDS
ELIOT
ELIZABETH
ELM
ELMWOOD
3
2
4
Lights
OFF
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
3
2
2
3
5
2
2
5
6
11
4
3
2
1
1
2
25
9
1
2
3
1
1
4
3
2
3
5
1
2
8
11
6
8
1
53
2
1
3
1
4
2
4
2
2
1
2150
17
3500
4000
5
6
3
3
3
3
9500
16000
25000
`17
5
2
2
5
6
3
11
4
3
5
1
3
2
27
9
3
3
2
4
4
3
1
1
4
3
2
3
5
1
2
8
12
6
8
1
53
2
1
3
1
4
2
4
Grand
Total
5
6
3
3
20
3
EMERSON
ENDICOTT
ENDICOTT PLAC
ESTEY
EVERENDON
EVERETT
FAIRVIEW
FAIRWAY
FALL
FARM
FELDMAN
FENCOURT
FIRST PARISH
FLAGSTAFF
FLINTLOCKE
FORBES
FOREST
FOX HOLLOW
FULLER
GLEN
GLENDALE
GRAND
GRAND ST
GREEN
GREENBRIER
GREENLODGE
GREENWOOD
GROVE
HARRISON
HARTWELL
HAWTHORNE
HEARTHRIDGE
HEATHER
HELEN
HEMLOCK
HERITAGE
HICKORY
HIGH
HIGHLAND
Street
HILLCREST
HILLSIDE
HILLSVIEW
HISTORICAL
HOMESTAD
HOWARD
HUBBARD
HUCKLEBERRY
HUDSON
HUNTER
1
Lights
OFF
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
2
4
2
3
1
3
5
4
6
2
2
8
2
9
6
2
4
1
1
4
4
4
2
1
6
4
11
1
7
1
1
3
2
4
10
2
4
13
8
2150
3500
4000
4
2
2
5
1
2
2
1
7
3
9500
16000
25000
`18
2
3
1
3
5
4
6
2
2
8
2
9
6
2
4
2
1
1
4
4
4
2
1
6
4
11
4
1
7
1
1
3
2
4
10
2
4
14
8
Grand
Total
4
2
2
5
1
2
2
1
7
3
INDEPENDANCE
INDIAN
JACKSON
JANICE
JEFFREY
JOHN
JOSEPHINE
KATHRYN
KEMPLEY
KENNEY
KENSINGTON
KINGS
KINGSBURY
KINGSLEY
KINGSTON
KIRBY
KNOB HILL
KRISTIN
LAKE
LAMB
LANTERN
LAUREL
LAWRENCE
LEDGEWOOD
LEGION
LEHAN
LEONARD
LEWIS
LEXINGTON
LILLIAN
LINCOLN
LINCOLNSHIRE
LINDEN GLEN
LONGMEADOW
LOUISE
Street
LUCE
LYNN
MANITOU
MAPLE
MAPLECROFT
MARGARET
MARILYN
MAY
MEADOWS
MECHANIC
MEETING HOUSE
MESSINGER
MEYER
MICHAEL
1
Lights
OFF
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
11
8
3
4
29
5
3
3
7
2
2
1
8
5
10
6
1
3
2
2
9
1
1
2
4
7
1
3
10
3
5
1
3
4
4
3
4
2150
3
1
1
3500
4000
1
2
5
2
3
3
3
24
3
11
1
1
9500
16000
25000
`19
4
29
5
3
3
7
2
2
1
8
5
21
6
1
1
3
2
2
9
1
1
2
12
7
4
3
10
3
5
1
3
4
4
3
4
Grand
Total
1
2
5
2
3
3
3
1
4
24
3
11
1
1
MOHAWK
MORRIS
MORSE
MORTON
MOUNTAIN
MULBERRY
NANCY
NATHANIEL
NEPONSET
NORFOLK
NORTH
OAK
OAK RD
OAKDALE
OLD COACH
OLD COUNTY
OLD MEADOW
OLD RANDOLPH
OLD RIDGE
OSAGE
OVERLOOK
OXBOW
PADDOCK
PAGE
PALMER
PAMELA
PARK
PARTRIDGE
PATRIOTS
PAUL
PEAR
Street
PECUNIT
PEQUIT
PEQUOT
PETERS
PHEASANT RIDG
PIERCE
PINE
PINE CONE
PINEDALE
PINEWOOD
PLEASANT
PLEASANT GARD
PLEASANT VIEW
PLYMOUTH
POND
POND VIEW
PONKAPOAG
POWDER HILL
2
Lights
OFF
1
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
9
6
5
11
4
2
2
1
1
2
1
10
1
1
3
3
30
11
4
2
1
7
2
7
1
2
1
9
1
5
3
4
1
4
5
1
3
2150
3
1
1
13
3500
4000
6
9
2
2
2
1
11
2
3
62
9
2
2
3
3
8
1
9500
16000
25000
`20
10
2
1
10
1
1
3
3
35
11
6
9
2
12
7
2
4
7
1
4
1
9
1
2
6
3
4
1
4
5
1
Grand
Total
9
9
2
2
2
1
11
1
3
3
76
9
2
2
3
3
8
1
PROSPECT
QUAIL
RANDOLPH
RAVEN
REBECCA
RED TAIL
REDMAN
RESERVOIR
REVERE
REYNOLDS
RICHARD
RIDGE HILL
RIVERVIEW
ROBERTS
ROBIN
ROBINWOOD
ROCK
ROCKLAND
ROCKWOOD
ROYAL
RUSSELL
RUSTLEWOOD
SANDY
SANFORD
SASSAMON
SAVIN HILL
SAWYER
Street
SEMINOLE
SHAWMUT
SHAWNLEE
SHEFFIELD
SHEPARD
SHERMAN
SHORT
SIOUX
SKYLINE
SNOWFLAKE
SOUTH
SPAULDING
SPRING
SPRINGDALE
SPRUCE
STAITI CIRCLE
STANDISH
STEEPLE CHSE
STONEWOOD
STRATFORD
STRAWBERRY
SUMMIT
Lights
OFF
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
1
8
2
63
3
5
2
9
2
29
4
2
6
2
3
4
4
1
15
12
8
4
5
2
1
1
2
6
1
2150
3500
4000
1
14
5
1
4
43
3
1
1
3
2
1
14
5
6
1
13
4
2
3
3
1
9500
16000
25000
`21
8
2
64
3
6
2
9
2
29
4
2
6
2
3
4
4
1
15
12
8
4
5
2
1
1
2
6
Grand
Total
1
14
5
1
4
43
3
1
1
3
2
1
14
5
6
1
13
4
2
3
3
1
SUMNER
SUNNYBROOK
SUNNYSIDE
SURREY
SUTCLIFFE
TALBOT
TALBOT RD
THOREAU
TILDEN
TIPPY CART
TOLMAN
TRACY WOOD
TRANSVERSE
TRAVERSE
TRAYER
TRUDY
TUCKER
TUNRPIKE
TURNPIKE
UNIVERSITY
VALLEY ST
VARNEY
VAUGHN
Street
VILLAGE GATE
WALFORD PK
WALL
WALNUT
WALNUT KNOLL
WALPOLE
WALPOLE PRIV
WALPOLE PRV
WAMPATUCK
WARD WELL
WARDWELL
WARNER
WASHINGTON
WATERMAN
WATTLES
WAYSIDE
WAYSIDE LN
WEATHERVANE
WENTWORTH
WESTCHESTER
WESTDALE
WHEELER
WIDBERG
WILDEWOOD
WILL
WILLIAMS
1
1
Lights
OFF
38
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
4
8
5
1
2
6
1
7
6
8
3
4
1
2
15
2
2
1
32
4
1
1
1
1
2150
4
3
3500
4000
4
3
5
4
26
1
1
4
1
6
1
102
8
1
7
1
3
11
10
9
5
1
16
13
4
9500
9
16000
1
5
25000
`22
8
5
1
2
6
1
7
6
8
3
4
4
1
2
15
2
2
2
34
4
1
1
1
Grand
Total
4
3
5
4
7
27
1
1
4
1
6
1
154
8
1
7
1
3
11
10
9
5
1
16
13
4
WILLOW
WINDHAM
WISTERIA
WOOD
WOODCLIFFE
WOODLOCK
YORK
002 GRAND
011 WILLIAMS
032 NEPONSET
214 YORK
252 DEADY AVE
258 DEADY AVE
300 RANDOLPH
376 NEPONSET
390 TURNPIKE
399 NEPONSET
500 CHAPMAN
601 NEPONSET
Street
607 NEPONSET
001027 TURNPIKE
001492 WASHINGTON
001500 BLUE
WHITE SISTERS WAY
Grand Total
1
Lights
OFF
1
1
1
64
1
1
1
1
2
2
1
6
1
61
1
1
1
1
1
1
1
1
1
2150
155
3500
2
4000
1
2
1807
9500
1
30
16000
15
25000
1
.
Canton Street Light Energy Efficiency Study
George A. Woodbury July 2015
`23
1
2
2
1
6
2
61
1
1
1
1
1
1
1
1
1
1
1
1
Grand
Total
1
1
1
2
2
2074