PMLD's Wind Farm

One of PMLD's Power Generating Wind Turbines

One of PMLD's 1500 kW Wind Turbines

Wind Farm Background & Zero-GHG Energy Production

PMLD Wind Farm Overview

In May 2002, an article on the Annual Town Meeting Warrant asked voters for permission to seek financing for $3.75M to replace 8 old decommissioned wind turbines with two new, larger wind turbines. The Article did not pass.

On February 11, 2003 the town held a Special Town Vote asking voters via Ballot Vote to vote on a Non-Binding Question "Do you favor the Board of Light Commissioners' plan to replace the eight (8) existing wind turbines with two (2) new larger wind turbines mounted on towers 213-230 feet high?"; which the voters voted 74% in favor of (605 out of 818 votes).

In June 2007 the Princeton Municipal Light Department (PMLD), in cooperation with Massachusetts Municipal Wholesale Electric Company (MMWEC), formed the Massachusetts Municipal Light Department Wind Energy Cooperative Corporation (MMLDWECC) to finance, own & operate the turbines.

The MMLDWECC owned and operated the two Fuhrlaender 1500 kW wind turbines on the south flank of Wachusett Mountain in Princeton until March 2015. In March 2015, the ownership of the turbines was transferred to the PMLD, and the Wind Farm Debt was refinanced through MMWEC 3 times to restructure the loan into short-term, long-term and bond payment schedules to levelize payments and reduce the interest rate.

24/7 SCADA Monitoring of equipment and operations are in place. Business Insurance policies were purchased to protect PMLD's investment. All maintenance and repairs are performed by PMLD staff who are trained as Wind Turbine Technicians, and contracts are in place with industry corporations to provide advanced monitoring and techincal support. Weekly, Monthly and Annual inspections of both turbine are performed and documented. A healthy stock of inventory, replacement parts and pieces are stored at PMLD.

PMLD continues to actively pursue Non-Profit Entities and offer the Sale of Wind Power the turbines generate to offset the Debt Obligation. The Wind Farm Debt will be paid off in 2026. Annually on average, the Wind Farm Debt is $0.05/kwh of the $0.2475/kwh rate customers pay monthly. Visitors are welcome to walk the trail off Westminster Rd. (on Old Stagecoach Rd.) up to and around the wind turbines to get an up-close view of these machines from the ground.

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Wind Farm Production

PMLD posts Year-To-Date Wind Productions, as well as Annual Historic Wind Production Data here.

Click the Data Sheet below to bring up a larger view.

PMLD Wind Farm Production Sheet
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More About PMLD's Wind Farm

History in Brief:

  • Planning, Permitting & Litigation took place for over 7 years (2002-2008), during which time the costs and partners changed significantly.
  • Construction began in 2009, just after the December 2008 Ice Storm.
  • Commercial operation commenced in May 2010.
  • One Gearbox failure in August 2011 on the South Turbine due to manufacturing defect was replaced in June 2012.
  • 3 Converters have been replaced in 2015 & 2017 on the South Turbine and 2018 on North Turbine

TODAY, PMLD Wind Power Generation is sold to:

  • The Sterling Municipal Light Department signed a 10 year PPA with PMLD to purchase 8.333% total output and capacity.
  • The West Boylston Municipal Light Plant signed a 10 year PPA with PMLD to purchase 16.666% total output and capacity.
  • The remaining 75.001% is sold through the Real Time Energy Market for Revenue to offset Debt Obligation for the project.

Additional Fun Wind Farm Facts:

  • The Fuhrlaender 1500 kW turbines are based on the design of American Superconductor (AMSC) in Austria.
  • There are approximately 6 of these units in the United States.
  • Each Tower height is 215 feet (or 65 meters) above ground level.
  • Each Tower was delivered and installed in three pieces.
  • The Tower sections were manufactured in Minnesota.
  • The maximum height of turbine structure with blade straight up is approximately 360 feet or 108.6 meters above ground level (AGL).
  • The Wind Farm Site is approximately 1,450’ above sea level.
  • Length of each blade is approximately 125 feet (or 37.5 meters), and each blade weighs 6 tons.
  • The Blades were manufactured in South Dakota.
  • The turbine speed is 17-20 RPMs.
  • The maximum blade tip speed is approximately 204 MPH.
  • The Power Output of each turbine is 1,500 kilowatts (kW).
  • The Generator on top of each tower weights approximately 60 tons.
  • The Annual Energy Output of the two turbines is approximately 4,000,000 kWh’s.
  • Both turbines generate the equivalent annual energy consumption of 330 homes.
  • The wind turbine manufacturer is Fuhrlaender of Germany.
  • The purchase and installation cost for the two turbines was approximately $7,300,000.
  • The minimum wind speed to start producing energy is 7 MPH (or 3 meters per second).
  • The maximum wind to produce rated power output is 27 MPH (or 12 meters per second).
  • The Cutout Wind Speed or wind speed too great for a turbine is 45 MPH (or 20 meters per second).
  • The Survival Wind Speed is 133 MPH (or 59.5 meters per second).
  • The expected lifespan of the wind turbine is 20-25 years.
  • During a power outage the turbines will not operate, to prevent back-feeding into the electrical distribution system.
  • The wind turbines use an anemometer and wind vane to sense wind speed and direction.
  • This data tells the wind turbines what direction to point towards and when to start or stop.
  • The blades act just like airplane blades and are lifted by the wind to turn the generator shaft.
  • The pitch of each blade is controlled to optimize energy production at various wind speeds.
  • The electricity generator feeds the electrical grid and feeds the customer load or demand for energy in the area it is connected to.
  • You cannot physically send the electricity generated from our turbines to someone else. That is handled by Financial Energy Contracts.
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