It’s popular these days to talk about producing much more of our electric energy from wind generation, as a clean way to reduce both greenhouse-gas emissions and our nation’s dependence on foreign oil. But while wind energy is something new and different, it’s generating more enthusiasm than electricity.

Wind-power capacity has tripled since 1998 to 6,400 megawatts, but it supplies less than 1 percent of the nation’s electricity. To encourage its growth, 17 states have established mandates requiring utilities to obtain set percentages of electricity from renewable energy sources by a fixed date — mostly 20 percent, including 5 percent from wind, by 2020. And Congress recently extended a federal tax credit for wind turbines that will make the cost of production competitive with electricity from plants running on coal or natural gas.

Wind energy has many benefits, and some of these government measures may help. But we should not be so naÃive as to think that electricity derived from wind will make much of a dent in greenhouse-gas emissions or imported oil. It’s clearly something we would all love to believe, that we could avoid all the issues of pollution and energy supply just by harnessing the wind. But wishing doesn’t make it so.

Advocates say that wind is free, it’s not beholden to other countries and it doesn’t produce smog or greenhouse-gas emissions. And that’s all true. The problem is that wind is unreliable; turbines turn only when the wind blows, and they typically operate at a modest 25 percent of capacity, compared to 40 percent at a gas-fired power plant or 90 percent at a nuclear power plant. When wind turbines aren’t operating, we have to get the power somewhere else. So they require expensive back-up electricity most likely from fossil fuels. That means more pollution, not less. And it means more dependence on imported fossil fuels — oil and natural gas — not less.

Another problem is that “wind farms” require large amounts of land.

Today, a wind farm that occupies 300 square miles produces only as much electricity as a typical 1,000-megawatt nuclear power plant. A study done by Jesse Ausubel, a professor at Rockefeller University, determined that, in order to meet U.S. electricity demand in 2002 with wind turbines operating around the clock, it would require wind farms covering more than 300,000 square miles, about the area of Texas plus Louisiana. The Energy Information Administration forecasts a 40 percent increase in electricity demand by 2020. So add Oklahoma and Kansas to the area of land needed for wind turbines.

Also, when wind turbines are sited in undeveloped or pristine areas, as is often the case, they detract from the environmental values of those areas. Plans by energy companies to erect wind turbines in esthetically attractive areas or coastal waters have encountered strong public opposition. And turbines have the added drawback of killing scores of migratory birds, waterfowl and raptors each year.

If we are serious about reducing our energy dependence and combating global warming, we will need to find a way to eliminate waste in our consumption of energy and make use of all emission-free energy sources. But there’s one source that can make a real difference, and that’s nuclear power, which is capable of meeting much of our nation’s growing power demands.

America can’t afford to have an energy policy that’s tailored to what’s “in” politically. We need to focus our efforts on expanding meaningful alternatives to fossil fuels that can have a major impact on achieving energy security and reducing global warming emissions.

Russell Mesler is an emeritus professor of chemical & petroleum engineering at Kansas University.