But first, windmill economics; A city explores ways to harness the bay winds

A city of 60,000 situated between San Francisco and Sacramento, Calif., is earning a reputation as a wind-energy center. Yet it has no windmills churning out electricity for commercial use--yet.

Its reputation rides on the 30-mile-an-hour wind gusts that whistle through the city and the surrounding area.

Pacific Gas & Electric Company already has built a 2.5-megawatt, 300 -foot-blade-diameter windmill nearby capable of energizing up to 1,200 homes. If the alternate power source proves feasible to utility officials, more wind turbines will follow.

The wind to be harnessed blows off San Francisco Bay, funneling itself inland through the Carquinez Straits.

The uniqueness of Fairfield, government seat of agriculturally inclined Solano County, is that the city itself wants to string windmills along the hilltops of its western flank.

The city's interest is spurred by its desire to attract industry. In 1980 an electronics firm explored locating in the area, but chose instead a site in another state because of less-costly and more reliable energy sources.

Some California business and industrial leaders charge the state is underestimating its future power needs. Consequently, they say, the state will be unable to meet its power needs without resorting to rolling brownouts. A brownout is the shutting off of electricity to a designated area at a specified time and is designed to conserve energy.

''That (loss of a potential manufacturing plant) made Fairfield take a hard look at the power situation,'' according to Jim Lerner, the city's wind-energy-development consultant. Mr. Lerner, who holds a doctorate in aeronautics and astronautics from Stanford University, resigned his six-year staff position on the state energy commission last July to embark on a career as an energy consultant.

If Fairfield can produce its own energy, it can assure a constant supply of power to industries that locate there. Many companies doubt the ability of the utility company to prevent brownouts, Mr. Lerner asserts.

Fairfield has several avenues it can travel, according to the consultant. It can:

* Set up a city utility district with its own generating capacity and transmission lines, but that is ''not a step to be taken lightly,'' Lerner contends.

* Establish a closed circuit between the windmills and the city's industrial parks.

* Sell the power produced to PG&E.

The closed-circuit idea would be ''really neat if you could take the output from the wind machines to the industrial parks and sell the excess to PG&E,'' Mr. Lerner said.

''But wind is variable. It blows strongest at night when the demand is least. And it's a seasonal thing.

''We haven't closed the door on a closed circuit, but it requires a lot more homework. It's a simple idea, but it may not be the best idea because the wind is an inconsistent energy source.

''For the near term, we'll interact with PG&E and sell it the power.''

Fairfield looks upon the windmills as ''added insurance,'' Mr. Lerner asserts. ''The city can't guarantee an incoming industry uninterruped power, but it can say the likelihood of brownouts is reduced. It gives the city one more card to play in attracting industry.''

Fairfield is ''shooting for'' 100 megawatts of power from windmills on several miles of hills west of the city, according to Lerner. But ''nothing is set in concrete'' at this point, he adds.

The city could acquire all the sites and equipment and thus operate such a wind farm itself, but it would be a costly venture.

Even though wind farms have customers for their electricity in the utilities, the capital costs of building a wind farm are enormous. Wind-energy hardware is still expensive, reports Lerner, because each windmill is literally handmade. If wind generators come into vogue, however, mass production will reduce the price of the equipment and, in turn, the cost of wind-produced energy.

Because of the attractiveness of tax credits to private developers, the more likely scenario for Fairfield is to work with a private developer in the construction of the wind farm while the city retains some control over the disposition of power.

Several developers have approached the city, but no decisions have yet been made, Lerner reports. However, one corporation, AeroTurbine Energy, Inc., of Englewood, Colo., leads the race for Fairfield's attention.

It has an option to buy 800 acres that could accommodate a wind farm. Further , it appears to enjoy a good working relationship with Boeing Engineering and Construction Corporation of Seattle, builder of one of several wind turbines now being developed, Lerner reports.

The Colorado firm has advanced plans calling for the installation of 40 Boeing 2.5-megawatt wind turbines for a 100-megawatt wind farm. Yet AeroTurbine has yet to win the Fairfield City Council's official nod.

Lerner continues to talk with other firms and is still ''tracking'' other wind machines besides Boeing's, including much small turbines.

The consultant expects Fairfield to have the first wind turbine ''on line'' and turning in the breeze by mid-1984.

Aiding the city in establishing its own wind farm is a joint project with the state energy commission calling for operation of a small 25-kilowatt windmill outside the city and a survey of wind velocity nearby.

Energy commission wind measurements throughout California in the late 1970s showed Fairfield and the surrounding region to be the second windiest in the state. (California's windiest spot is the San Gorgonio Pass where several experimental windmills already spin.)

The latest round of measurements is a more precise pinpointing of wind movement in the vicinity of Fairfield.

The joint testing accomplishes several things, Mr. Lerner observes.

''We're learning what it takes to own and operate a windmill since large windmills are still relatively unknown, although the technology is not new. We just have to learn more about the way (the wind) is channeled through the hills so that we know where to put the windmills and at what height they should be.

''There are a lot of unknowns. We just have to learn as we go,'' he said.