Renewable Energy

DOE Intiatives

Wind power



To help meet America's increasing energy needs while protecting our Nation's energy security and environment, the U.S. Department of Energy (DOE) is working with wind industry partners to develop clean, domestic, innovative wind energy technologies that can compete with conventional fuel sources. DOE's Wind Energy Program efforts have culminated in some of industry's leading products today and have contributed to record-breaking industry growth.

In 2005, the United States installed more new wind energy capacity than any other country in the world. The new capacity, totaling 2,431 megawatts (MW), was worth more than $3 billion in generating equipment, and it brought the total national wind energy capacity to 9,149 MW. That's enough electricity to power 2.3 million average American households. In 2006, an additional 2,454 MW were installed, bringing the Nation's total installed capacity to 11,603 MW.

Hydropower




With 80,000 megawatts of generating capacity, hydropower is the nation's largest renewable electricity source. Working with industry, the Wind and Hydropower Technologies Program pursues R&D to develop more environmentally friendly technologies to maintain the nation's existing hydropower capacity.


                                                            

Solar energy

                               

The sun has produced energy for billions of years.  Solar energy is the sun's rays (solar radiation) that reach the earth.

Solar energy can be converted into other forms of energy, such as heat and electricity.  In the 1830s, the British astronomer John Herschel used a solar thermal collector box (a device that absorbs sunlight to collect heat) to cook food during an expedition to Africa. Today, people use the sun's energy for lots of things.

Solar energy can be converted to thermal (or heat) energy and used to:

  • Heat water for use in homes, buildings, or swimming pools.

  • Heat spaces inside greenhouses, homes, and other buildings.

Solar energy can be converted to electricity in two ways:

  • Photovoltaic (PV devices) or solar cells change sunlight directly into electricity. PV systems are often used in remote locations that are not connected to the electric grid.  They are also used to power watches, calculators, and lighted road signs.

  • Solar Power Plants -  indirectly generate electricity when the heat from solar thermal collectors is used to heat a fluid which produces steam that is used to power generator. Out of the 15 known solar electric generating units operating in the United States at the end of 2006, 10 of these are in California, and 5 in Arizona. No statistics are being collected on solar plants that produce less than 1 megawatt of electricity, so there may be smaller solar plants in a number of other states.


Geothermal Power Plants

                       

Steam and hot water reservoirs are just a small part of the geothermal resource. The Earth's magma and hot dry rock will provide cheap, clean, and almost unlimited energy as soon as we develop the technology to use them. In the meantime, because they're so abundant, moderate-temperature sites running binary-cycle power plants will be the most common electricity producers.

Before geothermal electricity can be considered a key element of the U.S. energy infrastructure, it must become cost-competitive with traditional forms of energy. The U.S. Department of Energy is working with the geothermal industry to achieve $0.03 to $0.05 per kilowatt-hour. We believe the result will be about 15,000 megawatts of new capacity within the next decade.