I was disappointed to see that the very large negative effects on both Ohio's economy and environment were not discussed in the July 27 article "Wind power likely to blow in," on the wind-power projects in Champaign County.

The first issue is the high cost of wind power, which is about 2.5 to three times the cost of coal-generated power. Large wind-power projects exist only because of large government subsidies. Otherwise, wind power would be restricted to a few applications where the physical isolation of the electricity demand precludes extending the transmission network to the site.

The other major issue is the intermittency of wind power. Even on the best of sites, wind turbines generate usable power less than 30 percent of the time, and the experience of E.ON Netz Co. of Germany, which operates a large number of turbines, is that long-term availability for large sets of turbines is closer to 4 percent.

This suggests that the installed capacity of 300 megawatts in Champaign County will, in fact, produce as little as 12 megawatts of power on an annual average basis. The suggested license fee of $15,000 per year per landowner is more likely to be only $600 per year.

Intermittency means that wind turbines require backup from conventional power, meaning nuclear, coal, oil, gas or hydroelectric. In general, the engineering studies conducted by both the German company and by the UK's Royal Academy of Engineering indicate that 1 watt of wind-power generation requires 1 watt of conventional generation as backup.

T. Boone Pickens' claim that wind power will reduce the need for natural gas in electricity generation is spectacularly wrong. Wind power intermittency means that the backup unit must be very quick-responding, and this requires natural-gas-fueled turbines. So wind power means more natural gas will be needed for electricity generation, and since gas turbines are not as thermodynamically efficient as coal-fired power plants, more fuel will be required.

So, we will require two complete power generation systems: wind power and conventional, when we only need one, conventional. At present, wind turbines are few in number, and they get a hidden subsidy from our conventional plants' excess capacity.

As electricity demand increases, this excess capacity will slowly drain away, and the full negative impact will become apparent. E.ON Netz also notes that intermittency of wind-power supply reduces the stability of electricity-transmission networks, leading to more frequent power blackouts. The blackout of a few years ago was because of network failures as power plants were taken off line to protect them.

All in all, wind power will substantially increase our power costs and increase the frequency of power blackouts. What absolute madness.

Professor emeritus Civil and environmental engineering Ohio State University Mount Vernon