Schweizer has invested more than $1 million in this somewhat esoteric-sounding asset class, but he is not merely tilting at windmills. Wind energy is growing in popularity, with private investors seeking to garner strong returns by being at the forefront of a revolution in the energy markets. Individual investors are taking equity stakes in domestic wind farms and foreign turbine manufacturers; others are backing the design and construction of commercial windmills.

Wind energy is no longer a high-cost indulgence for environmentalists and corporations looking for some green window dressing. In the past decade, it has emerged as a viable alternative energy source because of several recent developments:

•Engineering advances have sparked the evolution of wind power, from small-scale uses to utility-scale power generation. New jumbo wind turbines can produce from 3 to 5 megawatts each, sufficient to supply between 900 and 1,500 average American homes.

•A worldwide focus on the effects of fossil fuel—based energy–especially concerns over global warming–has refocused government and energy industry attention on alternative energy sources.

•A recently extended U.S. federal tax credit brings the relatively high cost of wind energy into line with those of more popular fuels, such as coal.

•A number of populous states, including California, New York and New Jersey, have laws requiring a growing percentage of their energy to be produced from renewable sources.

Schweizer hopes to exploit these trends by positioning himself in wind energy in North America in the same way investors overseas have in recent years. "Europe is way ahead of us in the development of wind energy," he says. "With our electrical production problems and gas and coal problems, it’s important to try to develop a renewable source of electricity. Even China is developing extensive wind energy resources."