On a cloudy day in Denmark, a wind turbine is producing clean, renewable electricity. Right now, wind power is the best of the alternative energy sources. But again, there are problems. Some people think wind turbines are ugly. And, of course, there are days when then there is no wind.
So, how will our grandchildren get their energy? "We're going to need everything we can get from solar, everything we can get from wind," says Michael Pacheco, director of the National Bioenergy Center, part of the National Renewable Energy Laboratory (NREL) in Golden, Colorado."And still the question is: Can we get enough?