THREE HEADACHES

The other is the random fluctuations of wind power and the consequent need for storage. The easiest way is to charge batteries, but that is both costly and wasteful. Merriam (see below) reports an experiment in the 1950's in which as much was spent on the batteries as on the 2.5 kW turbine, but only 43% of the energy extracted from the wind (itself only a fraction of the energy contained in the wind) reached the load: 15% of it had to be dumped because the batteries were fully charged and the load was off (not needed); 19% had to be dumped because the batteries could not be charged fast enough when power was available; and 23% were lost (as heat) in charging and discharging the batteries.

Other forms of storage include production of hydrogen by electrolysis of water, and pumping water into a reservoir for use by hydro-electric generators.

A study by the Bureau of Reclamation proposes using the already operating Colorado River Storage (hydroelectric) Project and the existing power distribution network by adding a 98 MW wind turbine array in the wind-swept plateau near the Medicine Bow River in Wyoming, the most windy area in the US. The winddriven generators would be interfaced with the existing power grid and would not directly store their energy, but would conserve the water behind the hydroelectric dams, making it available for later use. The proposal envisions an array of 49 wind turbines, each with a 200 ft double blade. But even in this unusually favorable case (high winds, cheap land, existing hydropower plus power grid) a nuclear or fossil-fired plant could produce 10 times the power on 1/100 the land areas and at any instant when it is demanded.

[More: Beware of false optimism and Lovinsian claptrap with which the wind power field is flooded. Good introductions are Wind Power Machines by F. R. Eldridge (Oct. I 975), US Govt. Printing Office, stock no. 038-0002724; and M.F. Merriam, "Wind Energy for Human Needs," Technology Review, Jan. 1977. The Amer. Wind Energy Association publishes a newsletter and the Wind Technology Journal at 54468 CR 31, Bristol, IN 46507.]