11 big machines
|At a cost of $11 million, of which
64% came from Green Mountain Power and 36% from various subsidies, eleven
windmills have been built near Searsburg, Vermont.
The windmills produced 3.4 million kilowatt-hours of electricity in the first quarter of 1998. (Around-the-clock average power = about 140 kW for each unit.)
Each windmill has a three-blade rotor of 132-foot (40-meter) diameter, which turns at a constant 29 revolutions per minute. The power output of each unit is 550 kW when the wind speed is between 29 and 65 miles per hour (13 to 29 m/s).
(We may deduce that the availability factor was the true average power divided by the on-line power, namely 140/550 = 25%. In 1995, Vermont used 5.2 billion kWh. The wind power for the entire year will thus be about 0.26% of Vermont's electricity.)
The windmill data given herein came from Mechanical Engineering (pages 79-80, August 1998) (my comments in parentheses)