Wind Site Brings 6 MW to Vermont
By Ann Chambers,
Green Mountain Power Corp.`s new 11 windmill, 6 MW power plant is spinning power into the grid from its site along a ridge top near Searsburg, Vt. The wind plant was constructed by Green Mountain with financial and technical support from the Electric Power Research Institute (EPRI) and the U.S. Department of Energy.
“Not only does this break new ground operating turbines under the difficult winter conditions in Vermont, but they have also achieved a high level of community support and pride for the project,” said Tony Armor, EPRI director of generation technology development.
In the first two months of 1998, the plant generated more than 2.3 million kWh of electricity.
“We are pleased with the plant`s recent winter performance, which exceeded our expectations,” said John Saintcross, Green Mountain director of resource portfolio management. “Although experience at Searsburg is limited to a few months, we are optimistic that these turbines will withstand the rigors of the Vermont climate and the technology will prove itself a viable source of clean power in this region.”
The Searsburg site was selected for its strong and persistent winds and its proximity to existing access roads and transmission lines. The area is away from population centers and has few environmental concerns. Vermont`s winter winds will enable the plant to generate more electricity at the time it is most needed.
Green Mountain contributed about 64 percent of the $11 million cost. The remainder was contributed by the EPRI-DOE Wind Turbine Verification Program (TVP). The TVP was initiated in 1992 to evaluate prototype advanced wind turbines and to provide a bridge between turbine development and commercial application.
The plant has 11 Zond Z-40FS wind turbines, power collection and switching equipment, and a 1.5 mile transmission line which delivers the power to New England Electric Co.`s transmission grid. Each turbine consists of a horizontal-axis, three-blade rotor with a diameter of 131 feet, a gearbox transmission, an induction generator and a computer control system. The turbines have been designed to withstand cold climates, with black blades to absorb the warmth of the sun and shed ice, and gearboxes with heaters and synthetic lubricants.
The turbines turn at a constant speed of 29 rpm, generating 550 kW of electricity at wind speeds above 30 mph. Computer controls at the base of each tower adjust the turbine orientation and blade pitch to maximize power output.
A similar 6.6 MW wind project was installed by Central and South West Services in Fort Davis, Texas, in 1995. Future projects in Iowa, Nebraska, Oklahoma, Texas and New York will evaluate distributed wind generation. Two small wind projects in Wisconsin and Alaska are also associated with the TVP. p
Green Mountain Power Corp.`s new wind power plant nearSearsburg, Vt.