an expansion of nuclear energy, which also produces no greenhouse gases. But environmental groups do not want carbon-free energy at that price. ALEXANDRA McPHERSON, Greenpeace: Nuclear energy has no role in this debate. We have no safe way of putting away radioactive waste. There are cleaner alternatives, and Greenpeace firmly disagrees with the use of nuclear power. NARRATOR: Hydroelectric power has also recently come under attack. ALEXANDRA McPHERSON: Large-scale hydropower has been very disruptive in our rivers, specifically in the Pacific Northwest. We want to put an end to hydropower, and cleaner energy solutions are there. Solar and wind power. NARRATOR: In recent decades, great strides have been made to develop sources like wind power. Buffalo Ridge in North Dakota is one of the windiest locations in the United Sates. This wind farm has been sending electricity to the Minneapolis grid for over two years now. LARRY TAYLOR, President, NSP Electric: Southwestern Minnesota has some of the best wind characteristics of any site in the United States. The problem with wind is that the wind, on the average, blows 25 percent of the time. And it blows the strongest in the spring and the fall, when our loads are the lowest. At our peak times, in the peak summer, peak winter, it generally- a lot of times it produces zero. We can't count on it being there. We have to wait for the wind. If the wind's there, great. If it isn't, then we'll have to open the throttles on