Solar power is used to generate large amounts of power on a utility scale and to supply individual residences and businesses with electricity. This report focuses mainly on utility-scale, commercial, and residential solar power.
Utility-scale solar power plants supply large amounts of electricity to the power grid along with traditional sources of power, such as coal and natural gas plants. Solar power plants typically generate several megawatts of power, comparable to small or medium coal- or gas-fired plants. Plants only now in the planning stages are expected to produce several hundred megawatts, which would be comparable to a medium to large coal plant or nuclear plant.
Commercial solar power is used by business establishments, such as office buildings, warehouses, and retail stores, which are able to install large groups of solar panels known as photovoltaic (PV) arrays, on unused land, rooftops, or parking structures. These panels supplement the building's power supply, and, at times, may generate more electricity than the building consumes. Often, this excess power can be sold back to the local utility company.
Residential solar power is generated by homeowners who have solar panels installed on their roofs in order to provide power to their homes. This form of solar power is increasing in popularity. Residential solar power usually must be supplemented by traditional electricity from the power grid to provide additional electricity when the solar panels cannot meet energy needs, such as when it is nighttime or extremely cloudy.
Although some areas of the United States are better suited for solar power than others, solar energy can be harnessed in any geographic area because of the sun's vast reach. In 2009, California had by far the most solar power capacity at 1102 megawatts, followed by New Jersey with 128 megawatts. Nearly all states in the United States receive more sunlight per square mile than Germany, the world's leading producer of solar energy. Manufacturing of solar power equipment and components is located throughout the United States, with large plants in Massachusetts, Michigan, Ohio, Oregon, California, Wisconsin, Tennessee, New Mexico, Colorado, Georgia, and Texas. Other large solar panel manufacturing facilities are planned to begin construction over the next few years in many states.