The US could increase the proportion of electricity generated from renewable sources to about 10 times current levels over the next 20 years, and still see a 13 percent decrease in electricity prices, according to a new study by the Union of Concerned Scientists (UCS). Increasing the amount of electricity generated from wind, solar, plants and geothermal sources to these levels would freeze power plant emissions of carbon dioxide at about year 2000 levels, helping the US meet reduction targets set by the Kyoto global warming treaty.