U.S. Department of Energy has announced 43 cutting-edge research projects in 18 states that will accelerate innovation in clean energy technologies and improve how the U.S. uses and produces energy.

The topic areas for projects include:

*Grid-scale energy storage. This will be needed to enable the widespread use of two key renewable energy sources such as wind and solar power.

*Advanced power transistors for electrical substations. These could make the electrical grid more flexible and controllable for improving the efficiency and cost of power conversion and switching.

*Thermodevices for improving building's energy efficiency. A new air-conditioning system using water as a refrigerant and salt as the heat absorber uses reverse osmosis to efficiently separate water from the salt solution.

"These innovative ideas will play a critical role in our energy security and economic growth," said Energy Secretary Steven Chu when announcing the USD93 million funding for the projects. "It is now more important than ever to invest in a new, clean energy economy."

The projects - led by universities, small businesses, large businesses, by national labs, and non-profits - are funded from the American Recovery and Reinvestment Act through the Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E)

In three rounds of awards since last year, the agency has selected a total of 117 projects for USD349 million in funding, supporting research that can deliver breakthroughs.