U.S. production of renewable energy has increased in the past decade but it still lags far behind Europe and is only slightly ahead of Mexico, researchers said. The Natural Resources Defense Council said the United States got about 2.7 percent of its electricity from renewables in 2011, making it No. 7 among G-20 member countries. European countries get more of their electricity from wind, solar, geothermal and other renewable sources than any other region in the world, a NRDC release reported Monday. Renewable energy is expected to be a central issue of discussion at the upcoming Rio+20 Earth Summit in Brazil, with the NRDC urging countries to implement policies to increase the percentage of electricity they get from renewable sources to 15 percent by 2020. Some smaller, non-G-20 countries -- such as Spain, New Zealand and Iceland -- already get more than 15 percent of their energy from renewable sources, the report said. Favorable governmental policies and strong private-sector investments have resulted in a 300 percent increase in renewable energy production in the United States in the last decade, the NRDC report said.