Tuesday, October 06, 2009

Grand Meadow Wind Farm, Dexter, Minnesota

Some specs of a typical wind "farm":

The wind farm spans a stretch of farm fields six miles long and four miles wide, and is spread out over roughly 10,000 acres southeast of Interstate 90 three miles north and three miles south of Hwy 16, in Grand Meadow, Clayton, and Dexter Townships in Mower County.

Grand Meadow is a 67-unit wind farm consisting of GE 1.5 SLE turbines.

Power Production Capability: 1.5 MW each for a total of 100.5 MW.

Wind turns the blades, which spin a shaft through a gearbox that connects to a generator, which produces electricity. The 3 blades rotate (pitch) from 0 to 90 degrees allowing the power output to be controlled if desired. The amount of electricity generated is determined by the wind speed:
  • Minimum (0.1 MW): 7.8 mph (3.5 m/s)
  • Design (1.5 MW): 31.3 mph (14 m/s)
  • Maximum (1.5 MW): 55.9 mph (25 m/s)
The project was developed by enXco and constructed by Mortenson Construction in 2008. In December 2008 the wind farm became fully operational and was turned over to Xcel Energy.

The height to the tip of the highest blade is 389 ft (slightly longer than a football field).

Each blade is a composite fiberglass material weighing 13,900 lbs and is 122 ft long. [The blade assembly sweeps a vertical area of 1.15 acres.]

Each turbine base consists of a 52 ft × 52 ft octagon that is 7 ft deep. This requires 278 cubic yards (28 trucks) of concrete and 57,000 lbs of reinforcing steel. Each base weighs over 1.1 million pounds.

The base of each turbine uses approximately 1 acre of farmland.

There are approximately 37 miles of 3-wire underground power collection cables connecting the 67 turbines.

Source: Xcel Energy

wind power, wind energy, wind turbines, wind farms