Wind power 101 Posted by Dan McKay on December 22, 2009

WIND POWER 101

What will wind power do to the electric industry and your cost of electricity ? The electric industry relies on instantaneous supply to match instantaneous demand for perfect efficient operation. Unlike other commodities, electricity can not be inventoried to satisfy demand in the future.
Wind powered electricity is created only when the wind blows at the spot of the turbine and this is not a 24/7 event. Wind turbines, such as proposed for our mountain tops require 6 to 8 MPH wind to start rotation. No rotation equals no electricity. They will need 25 to 27 MPH winds to produce their rated capacity ( normally 1.5 to 3 megawatts; a common natural gas-fired produces 300 to over 500 mega watts ). With wind speeds from 25/27 MPH up to 55/56 MPH, the turbines will only maintain their rated capacity. The increased energy available from the wind as it’s speed increases above 25/27 MPH is unused. At 55/56 MPH, the turbines are supposed to automatically stop rotation as the stresses would cause turbine damage.
The turbine rotating at optimum wind speed according to it’s design, at best, captures 35 to 45% of the wind energy. They depend on air movement passing through the blades, therefore it is necessary to have a wind velocity ( movement ) behind the blades to allow air to move out of the way for incoming air.
The fuel is free, but a lot of it is unused, and the costs of capturing the usable part of this energy source is substantial. So substantial, in fact, that taxpayer money at the tune of billions of dollars is allocated to wind developers to keep them competitive to traditional generating stations. This money, just for one commodity: electricity. Consider this as the initial rate increase due to wind.
Now, let’s consider the effects of importing wind electricity into the power lines which feed our houses and businesses. Conventional power plants ( hydro, cogen, natural gas- fired: which we have in Maine and has the ability to supply over 100% of Maine’s demand ) produce nearly 24/7/365 and are very dependable. Maintenance shut down is usually only 5 to 10% of operational time. Because of this dependability, the people in charge of making sure that electrical supply is matched to demand can allocate their time to predicting demand for future orders of electricity. The industry is able to do that at 99% accuracy. With wind, an unpredictable supply factor is introduced, complicating everything. Standby power is required. Plants that are idle, but burning fuel during times of wind imported electricity must always be ready to compensate for lack of wind. The price for this compensation is established by what is called the “ spot market “ ( a daily and sometimes hourly event ). Could emergency situations when a power plant is on the “spot” mean emergency pricing?
One other point for consideration is the development of power lines to the scattered wind turbine sites. The “ smart grid “ and various required transmission upgrades needed to accommodate wind passes it’s cost of development and construction to the ratepayers.
Of course, even with the “ end all “ when these turbines are taken down, the development potential of the mountains remain because the roads and leveled spots have been built.
Freemont Tibbetts and Dan McKay