Wind Energy in Princeton Massachusetts


Prepared by Rick Rys P.E.  Rick is an internationally recognized Process Control Engineer with engineering experience in fossil, nuclear, and wind energy.  He has worked with the German firm Windtest-nrw since 2009 and operates his own consulting firm, R2Controls, since 1996. He has experience helping to solve many environmental and energy problems worldwide.


This web page provides some insight into the history of the Princeton Municipal Wind Farm up to 2015.  We hope these web pages will help keep the citizens of Princeton informed and help our town to get the most benefit out of our community wind farm.


Ten questions you might ask about the Princeton Wind Turbines


1.     Is Wind Energy a good way to make electricity? 

2.     Is Princeton a good site for wind?

3.     How do Wind Turbines actually work?

4.     What is the history of the Princeton Wind Turbines?

5.     Are the Princeton wind turbines successful?

6.     Are the Princeton wind turbines producing as much power as expected?

7.     How do the Princeton wind turbines compare to others in New England?

8.     What is the impact of the wind turbines on the PMLD power rates? 

9.     What impact have the wind turbines had environmentally?

10.What is the future for wind turbines?


While an attempt is made to answers these questions, the result is somewhat incomplete.  If you have better information or photos, please share them.



This is the plaque at the road to the wind turbines


On 12 December 2009 there was a commissioning ceremony for the wind turbines. The invitation included the photo below:


The picture below is looking at one of the PMLD wind turbines standing from below, it is hard to get a perspective of just how large these wind turbines are.


The picture below shows how the wind turbines can be seen on the horizon from the intersection of RT-290 and RT-140 in Boylston, ten miles away (Dec 2014). The top of Mt Wachusett can be seen to the right and Mt. Little Wachusett on the far left.



The two wind turbines can be clearly seen from Mt Wachusett (Dec 2014)


Zooming in a bit:






Zooming a bit more on the North tower:


 Is Wind Energy a good way to make electricity?

This question cannot simply be answered as “YES” or “NO” in every case, but the emerging answer is “YES” for certain locations.  As our world moves toward sustainable energy, the primary currently feasible option is Solar  - nuclear fusion from the sun. Even the energy in the Tides, Geothermal, Nuclear Fission, and human efforts with Nuclear Fusion are remnants of energy from stars of the past.  The amount of solar energy hitting the earth in 8 minutes is equal to the total consumption of worldwide electric power for a year. 


Solar power at the earth’s surface is a diffuse, non-dispatchable source of power.  Of the solar power options wind energy is relatively concentrated and worldwide wind power in 2013 was 318GW but PV power is growing faster and is at 138GW. The chart below shows the trend in new electric power sources in Europe. In New England very little new electric power has been brought on-line recently so like Europe, gains in solar and wind are a big part of the new power sources.  The trend in New England has been to move away from Coal and Nuclear but it remains to be seen if new pipelines will be built for increased Natural Gas, or if renewables including imported hydro power from Quebec will make up for the various plant closures we have seen.



Keep in mind that wind has been used to directly power our machines for thousands of years. The conversion of wind energy to electrical energy adds a level of convenience to get that power into the grid where it can get distributed to you.  The grid that likely powers the device you are looking at right now.


Consider that wind energy powered the sailing ships used to explore the oceans and enable world trade.


It was wind energy that pumped water for farming, flood control, and for milling grains.



Converting the energy of the wind into electric power is now a multi-billion dollar industry.  There have been notable failures along the way, and much has been learned about how to site wind turbines, how to design and erect wind turbines, how to connect them to the grid, and how to maintain them to operate efficiently.  Good wind alone is not enough; many other factors are involved.


You can find a good summary of the PRO’s and CON’s of wind energy at this site:


A great place to find information is on the “Resources” tab at the American Wind Energy Association.  Start with the “Basics” page.


A critical part of the answer lies in what the alternatives are.  As we searched the earth we found some stuff we could burn to make heat, and engineers figured out how to convert some of that heat to electric power:


Natural Gas:

Natural Gas (Methane) is 300 million year old fossil fuel and is the leading source of power in New England. Natural gas derived electric power has grown sharply in the past decade but future growth is not so clear.  There is now a glut of Oil and Natural Gas in the US and prices are at very low levels as we start 2015.  Ironically the leading cause of this glut is “conservation” resulting from the 2008 recession.  Nearly as significant as conservation has been, a huge game changer is “Hydrofracking”, a controversial technique to extract oil and gas out of rock formations using high-pressure water and proprietary solvents. In spite of this glut we have a shortage of Natural Gas in New England during peak winter months due to constraints on pipelines and gas distribution and a major conversion from by homeowners from oil to gas heat. Power plants are restricted from using pipelines during the coldest winter conditions to ensure homeowners have priority. While the combustion of natural gas is much less polluting than coal, natural gas has significant environmental issues. Hydrofracking makes potential water resources permanently contaminated.  In the next few years export terminals already under construction will put our US gas on the World market price.  Natural gas production leaks significant amounts of methane into the atmosphere. Methane far exceeds CO2 as a greenhouse gas. Methane combustion still puts plenty of CO2 out the stack.  At best natural gas is an interim solution, and we would be wise not to become dependent on it.



Oil is a fossil fuel like gas and coal. Generations in the future will look back at us as “hydrocarbon man”.  Peak oil will happen.  Conventional oil has peaked in ~2005.  Unconventional oil reserves are significant but come with increased environmental costs.  Tar Sands, Offshore oil, Artic drilling and Hydrofracking are driven by the huge financial gains, but increasingly horrific environmental costs.  “The Prize” is a Pulitzer winning book by Daniel Yergin. It is a good reference on oil history and old money and how we got to where we are.  Of course global population and economic development is a major driver.  Countries like China, India, Brazil and Russia want to live a high-energy consumption lifestyle like we have in the US. There are many ways we subsidize oil.  The aircraft carriers in the Straight of Hormuz are not being paid for by the oil industry they are protecting. Princeton more than most communities made an effort to see a future less dependent on hydrocarbons.



If you are old enough to remember the days of Admiral Rickover, you may recall the comment about Nuclear power:  It is not too much to expect that our children will enjoy electrical energy in their homes too cheap to meter.”  This overly optimistic statement came from an assessment of the amount of fissionable materials in the earths crust.  The energy available in fissionable fuels like Uranium and Thorium is about 90,000 times as great as all the energy of all the combustible carbon (Oil, Gas, & Coal) in the earth.


In New England we have Vermont Yankee, Millstone in CT, with Pilgrim and Seabrook nuclear power plants in MA.  The price for Nuclear power (as seen from ISO New England) is quite low at only a few cents per kw*hr. There is of course some concern this price does not include all the costs.  After Chernobyl, and Fukushima, and many other smaller accidents, we know there is a potential for disaster and the public fears Nuclear power.  Nuclear power is a potential target for those who wish to cause politically motivated fear.  We also know that radioactive spent fuel is accumulating at power plants without a long-term plan for disposal as Yucca Mountain project was abandoned without an alternative.  Consider also the Price-Anderson act that limits the liability of nuclear plants in case of accidents.  This subsidy means that nuclear plant owners are not responsible for all the damages they might cause in a serious accident.  Guess who pays for the rest. Of course the big advantage of nuclear power is it does not make CO2 and if everything runs according to plan nuclear power plants have less radiation emissions than coal plants.


In a battle between state and federal regulations, public pressure and economics have resulted in the recent shutdown of Vermont Yankee, and politically it is highly unlikely that a new nuclear power plant will be build in New England in the near future.  The costs of decommissioning Vermont Yankee and managing the waste it produced is now coming to bear.


Maybe someday we will figure out how to make Nuclear Fusion work, but that is a story for another time.



It is likely that you could build and operate a coal-fired power plant that can make power cheaper than wind power if you ignore the costs of hazards and pollution. If however you consider the hazards and environmental impacts of mining the coal, and the stack emissions of CO2, mercury, arsenic, lead, acid rain from NOx and SO2, soot, smog, toxic air pollution, it is clear that coal is a very dirty option. With the shutdown of most coal plants or conversion to natural gas coal is nearly extinct in Massachusetts.




Hydro power is generally considered green energy but has PRO’s and CON’s as well.

In relation to non-dispatchable power like wind and solar, hydro can be operated to accumulate water for future use when wind and solar are producing power.  The Northfield mountain project was specifically designed to balance power supply and demand, although originally built to support Nuclear power it works well for wind and solar as well. The main issue with Hydro is we have already built it at most of the available sites so it does not have the capacity to meet all the demand. There are several proposed high voltage DC power lines that can bring Quebec generated hydropower to New England.



It is clear that all forms of energy generation have negative issues regarding cost and environmental issues. To a large extent our economy is based on digging things up, consuming them, and making waste dumps in the air, water, and land. Some argue the GDP (Gross Domestic Product) is improved by doing this faster which, unfortunately, makes waste at a faster rate.   It is quite clear that Earths resources are finite, and it is the only decent planet in the neighborhood. Humans are increasing confronting the finite limits of the Earths resources.  The transition to a sustainable economy powered by the sun has made serious progress but has a long way to go.


It is a very challenging task to transition our suburban lifestyle to a sustainable economy. Consider the population of the planet in Jan 2015 is roughly 7287328960.  The amount of land on the planet is 57580000 square miles.  Divide these and you realize we have:


5.06 Acres per person.


Just think about how we might provide for all our food, fuel, shelter and possessions from this much land.  And think again how we need to dispose of all our trash.


Compared to the alternatives wind is a good option, but conservation is the best option.


Is Princeton a good site for wind?

The amount of power you can get from wind depends on how much wind you have at a particular location.  Less obvious is how important small differences in wind speed can make and how steady is the wind over the whole year. Power in the wind varies with the wind speed cubed. Double the wind speed and the power increases by 2*2*2 or times 8.  The difference between 8mph and 10mph is almost twice the available power 103/83 = 1.95. The power of a wind turbine depends on the size of the blade.  Double the blade length and power is times 4.


The figure below shows the wind resource in New England.  Wind happens at water and land boundaries that heat unequally, so that is evident in the D.O.E. map below.  The Princeton wind turbines are at a high elevation near the top of a mountain ridge. At the Princeton site predominant wind is from the northwest, and although it does not have the wind resource we see offshore it was determined (by multiple wind studies) to have enough wind to be a viable wind site. Average wind speeds at the hub height of the turbines are in the range of 15 mph.






It is standard practice to make a site assessment that includes measuring the wind before putting up the wind turbines.  As Princeton had wind turbines at the site already there was a natural advantage, but new wind turbines are much taller. The standard way to measure the wind resource is with a wind tower that has calibrated 3-cup anemometers mounted at various heights. Many towers are 60 meters tall, but some are 80 meters or higher.  The wind is measured for at least 1 full year as wind is very seasonal and the tower is typically removed after use. Sonar and Lidar methods are also available to measure wind resources without the need for a tower. 


This is how a meteorological wind speed-measuring tower is functioning.


This is a 100-meter tall wind-measuring tower and various instruments can be seen. 



In this report you can find the early thinking on wind resources for Princeton


“To evaluate the potential wind resource, PMLD indicated it used: (1) maps prepared by the Massachusetts Technology Collaborative (“MTC Wind Maps”) which indicate wind resources in Princeton and surrounding towns (Exhs. DTE-2; DTE-3), and more broadly throughout Massachusetts (Exh. DTE-1); and (2) the report “Preliminary Wind Energy Survey of the Town of Princeton” (“1980 Wind Survey”) prepared by Ocean Wind Energy for PMLD in1980 prior to the construction of the original wind farm in 1984 (Exh. JPM-3-10(e)).” Part of this early survey report looked at how wind shaped the tree branches. This was useful to narrow down various potential sites. Photos of tree branches are included in the report.


Today there are various 3-D modeling software packages that can take into account wind speed at known locations like airports and predict wind speeds at nearby locations taking into account the terrain and wind directions.


On the 25th March 2003 a guy wire failure resulted in the loss of a 165-foot wind measurement tower.  The light department arrived just minutes too late to save it.  No injuries occurred. A Geotechnical investigation showed the failure occurred when the anchor broke the rock plate.  The anchor was found still firmly attached to a small block of rock.


Over the years U-Mass provided (loaned) a number of meteorological stations. Princeton was able to return some of them without damage.


The question of the Princeton site for wind turbines is also a land use issue and not merely a technical decision of the wind resource.  Princeton has both the Minns wildlife sanctuary and the Wachusett State reservation nearby and a few close neighbors.  There is some risk to bats, birds, and the general loss of habitat for wildlife.  The Audubon society followed these wind projects and gave comments at various times.  They did not support wind turbines on sanctuaries they owned.  The Sierra club did not support the 2 new wind turbines as they were near the State Park. Some found the Sierra club opposition odd when there already existed a Ski Area on the mountain. While these organizations act to protect existing sanctuaries and state parks, they do support the environmental advantages of wind power.  The sight and noise of the wind turbines is not as aesthetically pleasing as mountaintop forest. Princeton is a good site for wind, but there are compromises made to be a good site for wind turbines.



How do Wind Turbines actually work?


Perhaps the first question is how does wind happen.  The basic answer is from unequal solar heating of the earth’s surface that causes local pressure variations.  Wind moves from high pressure to low pressure.


You may recall from high school physics the kinetic energy of a moving object is ½MV2 where M is the mass and V is the velocity. Moving air has kinetic energy and a wind turbine takes energy out of moving air, by slowing it down.  Of course a wind turbine cannot complete stop the air but an “ideal” wind turbine can get up to about 59.3% (Betz Factor) of the kinetic energy out of the wind. We mentioned above the power (the rate of energy transfer) varies as the cube of wind speed.  You can see that from the relation:



If the wind speed doubles the Mass of air doubles and the Velocity of the air doubles so the energy increases by a factor of 8 as we mentioned above.


Wind turbines like the current Princeton units need ~7 mph to achieve “cut in” velocity to start generating power.  Maximum power can be achieved at ~27 mph and as wind speed increases to ~56 mph the blade pitch is angled to keep the power within capacity. Over 56 mph the blades are stopped and the turbine rotated out of the wind to protect the equipment. The actual controls are much more complex as there are connection issues with the grid, issues of wind gusts, possibility of vibration or icing conditions, and many other internal diagnostics and protective functions. The control system prevents operation in highly gusty situations and if the temperature is less that 5 DegF.

More information can be found on the Furlander web site (FL 1500):


You can download the Furlander technical brochure from our website at the link below



What is the history of the Princeton Wind Turbines?


This is a photo of the 8 original wind turbines with Mt Wachusett in the background:




Princeton built the first wind farm on the existing 16-acre site off Westminster Road in 1984.  The site had eight 40kW Enertech wind turbines on 100-foot towers that operated from 1984 to 2004. These wind turbines produced about 2-3% of the town’s power, much less than original projections of 10%.  In 2004, PMLD manager Jonathan Fitch suggested the wind turbines were installed in a mature stand of 50-foot trees and that was a major reason they fell short of their power potential.  Taller wind turbines had been recommended but were not installed due to cost issues.  The site was named after the PMLD manager Richard Wheeler and was the first significant wind farm in Massachusetts.  These early turbines operated until 2003-2004 but were retired, as maintenance costs were so high that purchased power proved cheaper.


The start of the first Princeton wind project began shortly after Princeton rejected an offer from MMWEC to purchase a share in the Seabrook nuclear power plant.  MMWEC encouraged municipal utilities to invest in Seabrook as a long-term source of electric power.  While many municipal utilities did invest in Seabrook, Princeton was one of the few that rejected the offer.  As it turned out delays in commissioning Seabrook proved quite expensive for the other municipal utilities and Princeton avoided the cost of those delays.


Bruce Dean was an early advocate for comprehensive energy planning towards a sustainable future and was against the town investing in Nuclear power plants because of the hidden costs of decommissioning and potential environmental impacts. As a community organizer he formed an energy advisory committee and was an activist on this issue. Bruce Dean petitioned for an article on the warrant in the spring of 1978 asking MMWEC to consider the “cost” of electric power to natural life and not just the cheapest source of power.  This article failed and the letter was not sent.


In 1979 MMWEC was asking municipal utilities to buy into the Seabrook power plant.  Many informed and concerned residents met several times with commissioners and Selectmen. They sought a non-binding referendum with the PLMD commissioners on this topic.  The commissioners suggested there would be a low turnout at such a meeting.  At a selectmen’s meeting on 17 Sept 1979, there was a vote by the commissioners to hold a public meeting with MMWEC.  According to newspaper accounts, commissioners voted as follows:


·         Les Poole “I am agin it. I don’t seen anything to be gained”

·         Charles Hall “We owe it to the taxpayers to hold the meeting”

·         Roger Lyons “I guess it’s up to me. Yes. I think we should have the meeting Monday night.


On Monday 24 Sept 1979, 200 residents showed up to the meeting with many questions.  Bruce Bentley of MMWEC made a presentation on the Seabrook plan. The Princeton Financial Advisory board was on record against the purchase of Seabrook power. After 2 ½ hours of often-heated discussions, a non-binding vote was taken: 129 against and 68 for the purchase. Once it was clear that residents did not support purchasing a part of the Seabrook power plant the light commissioners honored public opinion and unanimously rejected the offer to purchase shares of the Seabrook Nuclear Power Project No. 6. Mr. Dean then approached the Selectmen to form an energy advisory committee, which they appointed and he co-chaired with Leslie Gold.

On 10 Dec 1979, sponsored by the Princeton Energy Committee, workshop presentations were made on weatherization and energy conservation.  David Nichols made arrangements for a very convincing slide show presentation by U-Mass professor Dr. William E. Heronemus.  This was the technical help that PMLD manager Dick Wheeler needed to get started down the path of wind energy.

Dr. Heronemus outlined the feasibility of wind power in Princeton.  Dr. Heronemus had an accomplished Naval history on nuclear submarines and was a professor of civil engineering at the University of Massachusetts.  He is considered the “father of modern wind power” and the town of Princeton was an early adopter that helped to jump-start the wind industry. The Princeton light department, aware of the potential for wind energy, contracted for two initial tasks with Ocean Wind Energy Systems of Amherst, MA. The first involved a field survey of sites thought to be particularly well suited for wind power.  The second task was the selection of 1 site of less than 1.5 square miles and making a detailed survey of the vertical wind profile.


On Sept 25th 1980, Ocean Wind energy systems issued the final phase 2 report for Data Collection and Site Selection for Wind Monitoring Instruments. The phase 1 report on biological survey had identified 5 sites (down from 8 or 9).


(1)     Brown Hill

(2)     Little Wachusetts (not considered)

(3)     Pine Hill (not considered)

(4)     Worcester Road

(5)     Calamint Hill


As it turns out none of these 5 sites were selected, once the Westminster road site became available.  U-Mass continued to provide technical support for the project including the supply of a several meteorological towers.


The excerpt below was written in 1968 by Bill Heronemus as Professor of Civil Engineering at the University of Massachusetts in Amherst:

"In the immediate future, we can expect the 'energy gap' to result in a series of crises as peak loads are not met. The East Coast will be dependent on foreign sources for most of its oil and gas. The environment will continue to deteriorate in spite of ever-increasing severity of controls. Air pollution, oil spills and thermal pollution are likely to be worse, not better in 1985. In the face of the continuing dilemma: power us. pollution: a third alternative [to nuclear and fossil energy} must be sought. It may be found in the many and varied nonpolluting energy sources known to exist in the US or its offshore aggregate. These energy sources, tied together in a national network, could satisfy a significant fraction of our total power needs in the year 2000"


This recent video on the 40-year history of the U-Mass wind program shows just how influential Dr. Heronemus was worldwide.


The Audubon society while supportive of wind energy in general would not support locations on their Wachusett Meadows sanctuary and had concerns about bird kills and other issues.  While mountaintops are an obvious location, the top of Mt Little Wachusett (1562 ft.) is home to the Minns Wildlife sanctuary and the top of Mt. Wachusett (2006 ft) is part of the Wachusett Mountain State Reservation system. These locations were not pursued.


In Jan 1984 Princeton residents voted overwhelmingly in favor of wind energy on 4 related articles giving the electric light department the go ahead to generate electricity, to purchase 10 acres of hilltop off Westminster road offered by Stanley Porter for only $400 per acre, to float a bond to purchase the wind turbines, and to authorize the town to enter into an agreement with a private finance group.


The Westminster Road property (1475 ft elevation) was not part of the initial wind survey, but it became available when the owner of the property sold it to the town to enable the wind project.  Some residents were surprised by the extent of tree removal as these early wind turbines were just barely above tree height and nearby trees needed to be removed. 


The original 8 Enertech wind turbines were very primitive by today’s standards.  They had fixed pitch blades and the supplier was little more than a small time fabricator.  PMLD located sources for the pieces and parts and became convinced they could maintain them, even if the supplier were to go out of business. There were no tax incentive or renewable credits in those days so this entire undertaking was very much breaking new ground. PMLD manager Dick Wheeler was following the public opinion to pursue wind energy and took the initiative to become a wind power generating utility.


To get started, when there was enough wind, the turbines were connected to the grid and motorized to get up to speed. There were plenty of maintenance issues handled by PMLD, including replacing twisted wires, failed generators, failed generator insulation, new mounting plates, and mechanical breakdowns.  Unlike modern wind turbines, the old wind turbines synchronized to the grid and spun at a fixed speed that was a multiple of 60 cycles per second.


With the retirement of the 14 wind turbines in 2004, U-Mass continued to provide support for the Princeton Wind energy program as Dr. Manwell assumed the lead roll in the wind energy program at U-Mass. U-Mass provided a new wind assessment tower and also provided assessment evaluations to justify the 2 new wind turbines. WPI also provided critical studies of wind resources.



At this time (January 2015) we have two 70-meter hub height Furlander wind turbines rated at 1.5MW each.  That is nearly 10 times the capacity of the original 8 wind turbines. The timeline below shows how the project with the 2 new wind turbines unfolded.




Picture of the early wind turbines from WPI article  - (note we are requesting copies of any good pictures of the early wind farm):



The photo below shows Bruce Dean in front of the original wind turbines.



Are the Princeton wind turbines successful?

A “YES/NO” answer to this question is not sufficient for anyone trying to understand the complexities involved.  In summary the wind turbines are technically working and making power at a “Capacity Factor” somewhat below their rating. Environmentally they are displacing power on the grid, so that aspect is obviously successful to the extent of the power they generate.  Financially the PMLD wind turbines have some management issues and we make an attempt to describe these below. How the financial accounting is done can steer this answer, but PMLD is constantly trying to improve on both the technical and financial performance.


Technical Success:

When wind turbines are installed and a wind study has been done, engineers calculate the expected “capacity factor”.  The capacity factor is the ratio of its actual output over nameplate capacity.  In the case of Princeton, in a discussion with Brian Allen in August 2014 the “capacity factor” in the wind studies was estimated at 26% of the 3MW rating. In 2014 the actual performance was in the range of 15-18% and closer to 18% towards the end of the year.


The turbines were installed in 2009 and after about 6 months of adjustments the 2 turbines were up and running by the beginning of 2010. The first year of operation was reported as successful.


In 2011 the south wind turbine had a gearbox failure due to a manufacturing defect in bearing assembly.  This put the wind turbine out of commission for 11 months while, repairs were made.  The gearbox issue was a significant setback due to difficulties involved with the wind turbine contractor, manufacturer guarantees, legal fees, and insurance coverage.


Financial Success:

Another measure of success is financial. In this area the Princeton wind turbines are struggling.  The original private venture arrangement with Community Energy Inc. (CEI) was cancelled due in no small part by delays caused by four lawsuits. The wind turbines cost $7.3 Million and were financed by Holyoke Peoples Savings bank with the help of a COOP arrangement with MMWEC.   Today the wind turbines are managed via the COOP arrangement with MMWEC and the town of Templeton joined the COOP in Oct 2009 with their wind turbine.  While some of the debt has been paid down, financing the remaining debt is another cost that is passed on to the PMLD ratepayers.


Financial reports for PMLD can be found on-line:


The early lawsuits against the wind turbines.


“Fourth Lawsuit filed against windfarm project”

The summary below is from the siting study:


The development process was significantly lengthened as a result of appeals of the Town’s site plan approval by individuals who were concerned about visual impacts, noise impacts and safety issues. Discussion with the PMLD and records of the EFSB zoning exemption decision indicated that one of the opponents was a restaurant owner who was concerned about visual impact affecting his business, and another opponent stated he was most concerned about ice falling off the blades and the resulting safety hazard, though he noted he was opposed to the project because of visual and noise impacts as well. The opponents appealed the special permit in May 2004 to the Land Court, and then the Land Court remanded the permit back to the Town for lack of sufficient basis in the decision. The Planning Board issued a supplemental decision providing reasons for its decision and sent it back to the Land Court. This process took a significant amount of time and in an effort to identify a path around the delay, PMLD worked with the Town to help re-write the Town by-laws to more specifically allow for wind turbines. In September of 2005, after the Town of Princeton issued its new wind by-law, PMLD filed for and received another site plan review approval. However, this decision was again appealed and spent time in the Land Court. Finally, to avoid further setbacks in the project schedule, the developer requested a zoning exemption from the Department of Telecommunications and Energy (DTE). PMLD was finally issued a DTE zoning exemption in September 24, 2007, almost 3 ½ years after PMLD first applied for local approval.

L2009-123 4-16 165122


During the appeal process CEI was purchased by Iberdrola, a large international wind farm developer. Iberdrola pulled out of the Project because of the costs of the lawsuits associated with the appeal process and the small size of the project. The developer explained that the small 3 MW project was not worth the cost and resources for Iberdrola to pursue when comparatively, Iberdrola could develop projects orders of magnitude larger in other states more easily that would be more profitable. As a result, PMLD lost its development partner and became responsible for the funding and full development of the Project.


The original idea was the wind power could be used by the town to reduce the cost of purchased power and provide a hedge against future increases in the cost of purchased power from municipal suppliers like MMWEC and NextERA energy.  Today PMLD is unable to directly buy the wind power from the wind turbines to offset the town’s cost of power.  Instead, PMLD is selling most of the power on the “real-time” market for less than (on average) the town pays for power from our current supplier, NextEra energy.  There are brief times when the wind turbines can produce more than 100% of the power used in town.  I.e. the town consumption could be 1MW while the turbines are producing 3MW if there is a strong wind.


Through the COOP, PMLD continues to receive payments for renewable energy credits or RECs.  These REC’s are a substantial benefit and are part of the state program to wean our dependence on fossil and nuclear power.


In the June 2014 PMLD meeting minutes discussed the REC situation and a controversial new net metering system.


Our best interpretation of what PMLD receives for revenue from the wind turbines includes the average real time rate plus the REC’s.   This means we are getting “real time” average $0.06/kWh  + $0.03944 REC/kWh = $0.0994/kWh.  PMLD does get a slightly higher rate from West Boylson and Sterling power sales.


In 2014, the power from the Princeton wind turbines is sold as follows:

·         8.3% West Boylston

·         8.3% Sterling

·         83.4% sold to the “real time” market at about 6 cents per kW*hr


Cape wind with strong support from Governor Deval Patrick and Energy and Environmental affairs commissioner Greg Watson managed to negotiate 50% sold to National Grid at $0.207/kw*hr +3.5% increase per year for 15 years. ($0.347/kW*hr after 15 years) and Cape Wind sold 27.5% of their power at $0.187 /kW*hr +3.5% per year. No other wind turbines in the state get that favorable rate, but it is clear that Princeton is not receiving a price for their wind power that distinguishes it as a clean source of power.  A small player like PMLD has so far not been able to achieve such a favorable price for it’s wind power. There has always been a government hand in the power business. In addition there are the hands of individuals and businesses that fight for what they believe is right. In the case of wind energy you can see that local, state, and federal government has been involved and that sometimes, individual residents can make a big difference on the outcome.


The gearbox issue was a contributing factor that reduced income for sold power, lost REC’s, and added legal costs. It also added additional financing costs.


In 2012 PMLD has made presentations to Fox News describing the wind turbine as a failed system.

and in 2013 PMLD manager wrote to the governor to ask for financial assistance:


In 2013 PMLD had investigated selling the wind turbines:


It is a difficult task to get keep up with all the developments and the actual operation of the wind turbines. This early article painted a slightly different picture:


Right now the average customer won’t see any difference with rates as the cost of owning and operating the wind farm is expected to match what the town would have paid for an equal amount of energy, said Fitch. “That’s what we expected when we first proposed the project. As energy prices go up over the next five to seven years, we should start to see more savings and customers will see more impact on their bills. The bills won’t rise. We’ve always communicated that the wind far would stabilize the rates over the long run.”

Extra energy produced at night is sold to ISO-New England,” Fitch said. “It’s not a significant amount of money. The turbine and scale of the turbines were selected so they wouldn’t produce extra energy on an ongoing basis that we’d have to sell outside the town. We didn’t want to have to find a home for the excess 12 months of the year. The whole goal of the project was to reduce our energy requirements. It would be a lot of work to sell the excess.”

In the figuring of financial performance one must consider the true costs of buying power from the typical municipal suppliers whose energy mix is largely fossil and nuclear based.  The environmental and security costs of these energy sources are not included in the purchased price.  Take note of the huge financial resources currently in play to block the EPA from enacting regulations on Carbon and other pollutants and you can see the so called “free market” does not include the true cost of energy commodities.


We have not really answered the question of the financial success with detailed accounting numbers, but have helped to describe the interplay of the variables.  The author would argue that if you consider the environmental costs of the options, the wind turbines are a great investment for the world, a challenging investment for Princeton, but an investment that preserves our environment and moves us to a more secure energy future.  The other way to look at this is we could have shut down the wind farm in 2004 and ignored the environmental issues of consuming gas, nuclear and coal and provided power to Princeton at a lower rate.


The Princeton wind project has been an incredible initiative and has certainly helped to kick-start the wind industry.  The financial benefit to the future of sustainable energy has been massive.  This story is not over, if we can find ways to sell wind power at a higher rate, keep the capacity factor high, and keep our financing costs reasonable, the future of wind energy in Princeton could be quite favorable for Princeton ratepayers and the planet.


Environmental Success:

Every kW*hr the wind turbines produce goes into the grid (The Eastern Interconnection grid is one of the 3 power grids in the US).  The grid is controlled by ISO New England and when wind turbines generate power then other generators on the grid adjust their power down to compensate.  You might think of this as when the wind power picks up somebody on the grid slows down how fast they are shoveling coal into a boiler. The pollution from that coal is avoided. In fact it is much more complex as ISO is like the conductor of an orchestra of power generators and consumers that constantly changes.  I suggest taking a quick look at their web site to see the fuel mix that makes our New England power:


Our main supplier to PMLD is currently NextEra Energy and they are only part of the power on the New England part of the grid. They do have a commendable amount of wind in their portfolio, but they are mostly fossil and nuclear. 




Are the Princeton wind turbines producing as much power as expected?

In order to achieve the rated capacity factor, assuming the original rating is correct, the wind turbines need to be in top operating condition, and the wind needs to be at the level of the study conditions.  As mentioned above the wind turbines were rated for a capacity factor of 26% but are actually achieving roughly 18%.


So: 26%*365days/yr*24hr/day*3.0MW*1000kW/MW = 6,830,000 kW*hr per year


In 2010, the windmills produced 6,001,302 kWh (according to reports by PMLD at that time) so that would be a capacity factor of about 23%. In 2014 our capacity factor has apparently fallen to about 18%.


So: 18%*365days/yr*24hr/day*3.0MW*1000kW/MW = 4,730,000 kW*hr per year


There are many things that can impact the capacity factor, such as wind amount, icing conditions, control adjustments, grid curtailment, and many other maintenance factors. PMLD has spent significant effort to train their staff on maintenance issues, and has installed a remote data monitoring system to help identify issues and speed restarts.  Wind turbines have lots of complex moving parts, instruments, and inspection requirements.  The challenge is to keep the wind turbines operating efficiently, and handle both preventive maintenance and equipment failures in a timely and cost effective manner. PMLD has spent a lot of time to identify sites that have the same types of turbines or components and share operating experience and maintenance procedures.  PMLD has made major investments in training their staff and other towns in MA often look to Princeton to provide advice. The turbines are inspected weekly with 2 major maintenance checks per year where all available bolts are checked for torque and structural and equipment inspections are made.  The Bachmann control system allows experts from American Superconductor to remotely access the systems and assist PMLD with diagnostics when needed. PMLD keeps a significant inventory of spare parts to insure the wind turbines stay in operation with a high capacity factor and minimum down time.  Many of these parts need to be purchased from European suppliers.  PMLD coordinates with other wind turbine sites in New England that have common equipment.


How do the Princeton wind turbines compare to others in New England?


What we find is wind in New York State dominates the wind Turbines in New England with Maine a distant 2nd place. Off-shore wind turbines are really a different class all together and so far the big projects like the 468 MW Cape Wind project or the 30 MW Block Island wind farm have not started operation. Cape Wind has been delayed by 32 Lawsuits so far funded primarily via Billionaire oil magnet William Koch of Osterville and The Alliance to protect Nantucket Sound he formed with his donations.


Recent developments show these delays are threatening to cancel the Cape Wind Project.  It is interesting that Seabrook ran into delays and resulting financial issues and was ready to fold but was saved by investment support.  It remains to be seen if Cape Wind can recover.



New England Wind Turbines (3Q 2014)


# of Wind Turbines

Installed Wind Capacity

New York






New Hampshire









Rhode Island







In Massachusetts we have most wind resources on the coast and in the mountains:



Some links to other wind system in Massachusetts


What is the impact of the wind turbines on the PMLD power rates?

PMLD has increased their rates for 2015.


The Board of Light Commissioners approved an electric rate change and increased the rate an additional $0.0449 per kilowatt (KWh)to take effect on the February 1, 2015 bill cycle. At a public meeting held on December 10, 2014 the Board voted unanimously in

favor (3-0) to increase the electric rate. This sets the residential rate at $0.2369 per KWh.

 quote from 2013 town report:

Long Term Energy Contract In October of 2013 the Board of Commissioner's achieved their goal to stabilize rates and signed a long term energy contract with NextEra Energy. The energy contract establishes set energy rates for PMLD for the next five (5) years, an additional five (5) years to be negotiated one year at a time. In 2013 PMLD purchased energy through the Massachusetts Municipal Wholesale Electric Corporation (MMWEC) at fluctuating rates on the open energy market and also purchased hedging for the forecasted energy needs at open market prices. This was a challenge that often times left

PMLD very exposed to a volatile energy market with no relief in sight based on industry

projections. This exposure to high market prices caused PMLD to apply a Purchased Power

Adjustment Cost (PPCA) on monthly bills to customers for March, April and May of 2013 at

$0.035, $0.02, and $0.01 per KWh respectfully. The energy contract with NextEra Energy provides PMLD the stability in energy rates, which is much needed in order for our department to work towards achieving our long term goals to rebuild reserves and invest in infrastructure. PMLD is confident that this was a necessary and prudent business decision that will benefit the ratepayers for many years to come.


The PMLD web site in the Fall 2014 had included a breakdown of the cost of power in Princeton.  Of the $0.0192 per kW*hr rate at that time, $0.0047 is allocated to pay down the debt of the wind turbines.  With no recent extraordinary expenses related to the wind turbines the February 1, 2015 rate increase does not appear to be directly related to the wind turbines or the cost of power from NexERA.  


What impact have the wind turbines had environmentally?

In Massachusetts as a whole:

Generating wind power creates no emissions and uses virtually no water.

·         Annual state water consumption savings: 41,000,000 gallons

·         Equivalent number of water bottles saved: 437,000,000

·         Annual state carbon dioxide (CO2) emissions avoided: 110,000 metric tons

·         Equivalent number of cars taken off the road: 19,400

·         Add to this the kick-starting impact that Princeton helped to establish the early wind industry and the resulting technology advances.


What is the future for the wind turbines?


According to AWEA

Massachusetts adopted a renewable portfolio standard (RPS) in 2002, strengthening it in 2008 with two standards. The Class I standard for new resources calls for 15% of all retail electricity suppliers sales to come from eligible renewable energy resources by 2020, with an additional 1% escalation each year thereafter. Wind energy has historically been the renewable resource chosen to meet RPS requirements, fulfilling 86% of RPS requirements through 2011.


Now it is a little hard to predict the energy future in New England, and these portfolio targets could change.  The political, environmental, and business forces could reshape the policy in many different directions.  Considering the current policies we can expect wind power to grow.  You can see that our wind resources are mostly on Cape Cod and especially off shore and the Cape Wind project will be a good test of that.  Also don’t rule out Solar PV growth as a way to achieve these renewable energy targets, as there is great interest to convert brownfield sites like landfills to solar farms. In the long term offshore wind is bound to be an energy source that will grow in the future.


This article represents the ideas and research done by Rick Rys who would like to thank PMLD and many others for providing background and information on this daring and innovative project. Data to support this report comes from more than 100 news accounts and documents as well as discussions. The Princeton Community has shown great determination, a strong environmental consciousness, and a desire for adventure, and old-fashioned American ingenuity. Please provide any supporting information, comments, criticisms, photos, or note any errors or omissions to or to

Last modified: 18 August 2023