Denver — In 1948 Daisy Mae Epperson of Rock River, Wyo., wrote to her congressman asking why the federal government didn't build some machines to convert Wyoming's bountiful winds into electricity.
She got her wish with the dedication of two giant wind machines in Medicine Bow, just down the road from Rock River.
The wind turbines, a Boeing Mod-2, which produces 2,500 kilowatts of power, and a Hamilton Standard W.T.S.-4, which produces 4,000, were funded by the Bureau of Reclamation as a demonstration project of large utility-size windmills.
At the moment the nascent windpower industry is facing a series of technological, regulatory, and economic challenges. Yet experts believe that the wind might someday supply 5 quadrillion Btu, which would be equal to the nation's entire hydropower resources.
Hopes are that megawatt-size machines, such as those at Medicine Bow, will help capture this diffuse energy.
How did the Bureau of Reclamation, better known for dams than windmills, get into the wind business?
In 1976, after the first oil crisis, the bureau began a search for methods to enhance power generation from its existing facilities. After finding inspiration in a Swedish experiment, two bureau engineers, ironically named Stan Hightower and Abner Watts, proposed a simple - and elegant - plan.
If the bureau meshed megawatt-size wind machines into its existing hydropower grid, it could conserve water when the wind was blowing (allowing reservoirs to act as storage batteries), and during calm spells, hydropower could ''firm up'' the more sporadic wind-generated electricity.
The wind turbines at Medicine Bow are huge - more than 300 feet high - and sophisticated. Both turbines are computer-monitored. If ice forms on the propeller, for example, a sensor triggers an alarm to halt the blade.
Some part of this technology was supplied by another federal agency which might also seem misplaced in a wind project, the National Aeronautics and Space Administration.
Three years ago Vernon Weyers was suddenly transferred from launch vehicles to wind machines. Mr. Weyers recalls that after he told his children the news, they replied: ''Dad, you've become the first man to go from the space age to the stone age in one day.''
Yet, says Weyers, ''the basic principles of aerodynamics, systems integration , and structural analysis are the same. We've just transferred the technology.''
Since the Bureau of Reclamation eventually plans to let contracts for a 100 -megawatt wind farm in Wyoming, the competition between Boeing and Hamilton Standard has been fierce. ''This is the first time we have had two different designs competing side by side,'' according to bureau engineer Watts.
In theory, large machines do have an economy of scale that smaller turbines can't match, but there are those in the wind industry who feel that the two companies are on the wrong path.
''I think these giant machines will be dinosaurs,'' says Jay Carter Jr. of Carter Wind Systems. ''For these large aerospace companies, bigger is better, but they aren't yet cost-effective and government subsidies won't be here forever.''
Mr. Carter's own 25-kw. machines are back-ordered 21/2 years, and his design is so respected that Hamilton Standard has bought an interest in the smaller company and plans to monitor a 25-kw. Carter turbine in Medicine Bow.
Although it would take 160 of Carter's machines to match the output of one Hamilton Standard W.T.S.-4 - the world's largest wind turbine - if Hamilton Standard or Boeing cannot build and sell enough machines to gain the benefits of mass production, the large wind machines may never grab a significant market share.
As Bob Bussolari of Hamilton Standard puts it when asked the price of its turbine: ''You don't want to know the price of the first Model T; the one you want to buy is the 1,000th.''
''But if Hamilton Standard doesn't sell the 10th unit,'' says Don Hardy of Pan Aero Corporation, a Denver-based wind farm company, ''they'll never sell the 1,000th.
''These large companies have to price that first unit into the marketplace, and that requires a commitment to manufacture it at an initial loss.''
Currently, both large and small wind-turbine manufacturers are relying on third-party, venture-capital firms, such as Pan Aero, to keep the industry alive. But third-party developers are having their problems as well.
High interest rates, the oil glut, and legal challenges over a program that guarantees small energy producers a market and a fair price for their electricity are slowing the emergence of the industry.
''Merrill Lynch tells us we have to show a return in the high 20s to low 30s percent,'' says Ethan Thorman of Windfarms Ltd. ''And for us to do that, we need those federal energy credits which Reagan has threatened to cancel (and which are due to lapse in 1985 in any event).''
''The nation can't afford this short-term, next-quarter, bottom-line mentality when it comes to energy matters,'' according to Pan Aero's Hardy. ''It is intolerable, if not ridiculous, that we're still so dependent on Mideast oil.''
Despite the regulatory and economic barriers to long-term and large-scale wind development, Jay Carter Jr. remains optimistic.
''Wind will be stronger in 20 years than it is today, and stronger in 50 years than in 20,'' he says. ''There is 5 percent of the nation's energy blowing around free out there; and while the utilities right now have a wait-and-see attitude, they'll soon be scrambling all over themselves to get every part of it.''