Nebraska utilities will likely continue to rely heavily on coal, natural gas and nuclear power to produce electricity until someone develops a cost-effective way to store power. At an energy outlook conference in Kearney, Nebraska Public Power District President and CEO Pat Pope said coal, natural gas and nuclear remain popular sources of electricity because they are reliable and economical. Pope said even when natural gas was cheap, Nebraska's biggest and most-efficient power plant, Gerald Gentleman near Sutherland, was cheaper.