<P> In 2009, President Barack Obama in the inaugural address called for the expanded use of renewable energy to meet the twin challenges of energy security and climate change . Those were the first references ever to the nation's energy use, to renewable resources, and to climate change in an inauguration speech of a United States president . President Obama looked to the near future, saying that as a nation, the United States will "harness the sun and the winds and the soil to fuel our cars and run our factories ." </P> <P> The president's New Energy For America plan calls for a federal investment of $150 billion over the next decade to catalyze private efforts to build a clean energy future . Specifically, the plan calls for renewable energy to supply 10% of the nation's electricity by 2012, rising to 25% by 2025 . </P> <P> In his joint address to Congress in 2009, Obama stated that: "We know the country that harnesses the power of clean, renewable energy will lead the 21st . century...Thanks to our recovery plan, we will double this nation's supply of renewable energy in the next three years...It is time for America to lead again". </P> <P> According to Clean Edge, there's little doubt that the future of energy will be cleaner . The transition from carbon - intensive energy sources like wood, coal, and oil to natural gas and renewables, is well underway . For much of the developed world, and for developing nations, the "future looks increasingly like it will be built off of a mix of energy efficiency, renewables, the electrification of transport, and lower carbon fuels like natural gas". </P>

How has the use of alternative energy sources changed over the years in the united states