The May 13 Bangor Daily News carried a four-column headline: “Wind power aired at energy talks.” The piece, by Bruce Bartlett of the Saint John Telegraph Journal, contained the following information: 1) 170 wind machines were proposed between Cape Cod and Nantucket Island; 2) 26 square miles of ocean would be committed; 3) the towers would be 426 feet off the water; and, 4) If built today it would be the largest single wind installation in the world.

The public should play a significant role in the formation of energy policy, but how can that public make informed judgments when such scanty information is available? It seem to me that Bartlett should have included information covering: 1) How much electric energy will this system generate each year; and 2) Is this a significant fraction of the electricity used in New England? 3) Can other power plants by abandoned? And 4) Will the use of wind energy save natural gas? Etc.

Here is relevant information on that proposed wind installation (information reporter Bartlett did not include but must have been available). Each of the 170 wind machines has a 100-meter diameter rotor. The area swept by the rotor disc is about 8,000 square meters. If these units are as good as the units now operating in Germany and Denmark, the output will be about 1,000 kilowatt-hours a year for each square meter of rotor disc. Based on these assumptions about 1.3 billion kwh a year will be generated from this wind farm that covers 26 square miles of ocean. I checked the Cape Cod Wind Energy Web site (www.capewind.org). They are more optimistic. Under the heading “producing energy,” an annual energy output of 1.491384 billion kwh is listed. (The output is reported to seven significant figures for a power plant that has yet to be constructed. Does this say something about their credibility?)

How does this fit into the energy use pattern of New England?

I checked the “Independent System Operator of New England.” The winter peak energy use in New England is about 19,000 megawatts; and the summer peak about 20,000 megawatts. The all-time peak: June 6, 1999 – 22,544 megawatts. If the proposed wind farm had been in operation on June 6, 1999 (and – a big IF – the wind had been blowing at the design condition) then the wind farm would have produced 420 megawatts for every 22,544 needed.

The probability that the wind farm would put out its maximum effort to coincide with the maximum system demand is a long shot indeed. The annual electric energy use in New England is about 100 billion kwh. As stated above, the wind farm will produce about 1.3 billion kwh a year, which is less than 2 percent of New England use. (Maine Yankee, in a bad year, produced 5 billion kwh.)

Nuclear stations operate about 90 percent of the time. When electricity demand is low in the spring and fall, nuclear plants are re-fueled and maintained. When the demand for electricity is high, during mid-winter and during the air-conditioning season, nuclear plants will operate at full load. The wind on the other hand is willy-nilly. Wind gusts of 100 miles per hour have been recorded at Logan airport. Under these conditions all wind turbines will be secured and no electric power will be generated. Other days the wind velocity will be below 8 mph and the wind machines will simply stand still.

The system operator cannot choose these no-wind-energy days. This inability of wind energy to be “dispatched” is frustrating. But, after all, we are talking about less than 2 percent of New England energy; so who cares?

As long as the wind component of the electricity generation system is a small fraction of the total demand, and significant generation by natural gas is available, the use of wind machines can be made interchangeable with natural gas. The wind will save natural gas, and that is good.

But the question remains: As the fickle wind energy is backed up by precious natural gas what is the source of baseload, 24-hour-a-day, electricity? Coal and nuclear are the traditional answers. What will replace them? Certainly not the wind.

Richard C. Hill, of Old Town, is emeritus professor of mechanical engineering at the University of Maine.