A new federal government report concludes that by 2015 the cost of solar power will be the same as the cost of power from the electrical grid and could even be less by 2030.

Released this week by Vice President Joe Biden, the report predicts that the cost of generating power from rooftop solar panels will drop from the 2009 cost of $0.21 per kWh to $0.10 per kWh in 2015, which is equivalent to typical household electricity rates. Further, the cost of rooftop solar power could drop to as low as $0.06 per kWh by 2030. At that cost, solar power will be significantly cheaper than household electricity rates, allowing an average household to save more than $400 per year in electricity bills.

The study focused on the impact of technological innovations funded by the federal American Recovery and Reinvestment Act, established in 2009 in response to the U.S. financial crisis to create new jobs and spur economic activity. The $787 billion act includes $100 billion for science and technology projects including a nationwide smart energy grid, electric vehicle manufacturing, and development of regional high-speed rail systems.

“We’re planting the seeds of innovation, but private companies and the nation’s top researchers are helping them grow, launching entire new industries, transforming our economy, and creating hundreds of thousands of new jobs in the process,” Biden said.

The report also predicts that the country’s capacity for renewable energy generation will double by 2012, thanks in part to more than $23 billion of Recovery Act investments earmarked specifically for wind, solar, and geothermal projects.

As much renewable-energy-generating capacity will be installed in the next three years as the U.S. had in the previous 30, the report states, growing to 57.6 gigawatts by the end of 2011, enough to power 16.7 million homes.

Examples of Recovery Act-funded energy-related projects include:

• The largest photovoltaic power plant in North America, the 25-megawatt DeSoto Solar Park in Pensacola, Fla., consisting of over 90,000 solar panels and providing enough power for 3,000 homes.

• Solar manufacturer FirstSolar’s expansion of its manufacturing plant in Perrysburg, Ohio.

• Thin-film solar manufacturer Solyndra’s high-tech solar module manufacturing facility in Fremont, Calif., with the capacity to produce modules totaling 230 megawatts each year.

• The 400-megawatt BrightSource solar thermal project in the Mojave Desert, designed to be the world’s largest solar thermal facility with approximately 349,000 mirrors.

• Massachusetts-based FloDesign’s development of a novel shrouded wind turbine design with advanced aerospace technology that should dramatically reduce the cost and noise of wind energy.

• The development of new approaches to make solar cells much less expensive by companies like 1366 Technologies and Semprius.

• The addition of 18 million new residential smart meters to the 8 million currently in use.