Solar, wind, geothermal and biomass energy technologies as they are today could technically contribute up to 10 percent of U.S. electricity by 2020 and 20 percent or more by 2035, the National Research Council said in a report Monday.

Currently only 2.5 percent of all the U.S. electricity is generated from those renewable energy sources compared to 48.5 percent produced from coal. However, the study today suggests that the technology is not a problem, the challenge for the U.S. is the infrastructure such as the transmission capacity and the electric-grid, the National Research Council said today.

Necessary improvements include the development of intelligent, two-way electric grids; large-scale and distributed electricity storage; and significantly enhanced, yet cost-effective, long-distance electricity transmission, the report said.

It is needed an understanding of the scale of deployment that will be required to achieve a significant contribution of renewable energy to the U.S. electricity, the report said. Long-term and consistent policies that encourage the generation of renewable electricity are also needed, it adds.

The Obama administration is seeking to boost renewable energy sources in the country to reduce emissions of greenhouse gases into the atmosphere. It is a move aimed to reduce the impact on global warming.