As the name implies, solar energy is generated using the sun's powerful rays. Because sunlight is inexhaustible, solar energy is a valuable renewable energy source – capable of directly generating heat, light and electricity.
According to the U.S. National Renewable Energy Laboratories (NREL), the amount of energy from the sun that falls to the earth in one day could supply the entire world's energy needs for 27 years! Developing technologies that take advantage of the clean abundant energy of the sun is important to reducing greenhouse gasses and helping to stimulate the economy.
There are two ways that sunlight can be converted to electricity:
1) Directly, as in the case of photovoltaic (PV) applications
2) Indirectly as in the case of solar thermal applications
Photovoltaic (PV) Applications
Photovoltaic (PV) cells convert sunlight directly into electricity and are made of semiconductors such as crystalline silicon or various thin-film materials. Photovoltaics can provide tiny amounts of power for watches, large amounts for the electric grid, and everything in between. Solar panels made up of PV cells are the most widespread and recognizable method for converting the sun's rays into electric power - you might have even seen solar panels on homes and businesses in your neighborhood.
Solar Thermal Applications
Solar thermal collectors capture heat from sunlight and use it in a variety of ways. High temperature thermal collectors utilize mirrors or lenses to concentrate sunlight, collect its heat, and convert the heat into electricity. Most large utility scale solar facilities are designed in this way.
On the other hand, low-temperature thermal collectors use heat directly for hot water or space heating for residential, commercial, and industrial facilities.
Benefits of Solar Energy
Sunlight is a valuable renewable energy source that, when used in place of traditional fossil fuels, can help reduce greenhouse gases and stimulate the economy.
- Solar is 100% pollution-free—Solar power is one of the cleanest sources of energy because it does not emit any pollution when it is produced or consumed. This is important because most of the electricity in the U.S. is made from non-renewable, polluting sources such as coal, which makes the traditional production of electricity the largest source of industrial air pollution in the U.S. Pollution-free sources of energy, like solar, can help reduce carbon dioxide (CO2) emissions associated with electricity consumption.
- Solar is a renewable resource -- Solar is an inexhaustible resource, which means it will never run out, unlike limited and polluting fossil fuel sources. The possibilities with solar are endless. The amount of energy from the sun that falls to the earth in one day could supply the entire world's energy needs for 27 years!
- Doesn't require fossil fuel extraction—which means we are not damaging the land when we produce and consume solar energy.
- Solar brings us one step closer to energy independence—producing renewable energy at home helps reduce our dependence on foreign fossil fuels, therefore helping secure America's energy future.
- Consumer support of solar helps increase demand for more solar facilities—the more people choose to install solar on their homes, the greater demand there will be for more home solar systems and larger-scale solar farms.
- Supports green job growth—the more we support renewable energy development, the more employment opportunities are created in the green job sector, helping to stimulate our economy.
- Solar panels make financial sense for homeowners—solar systems installed on both new and old homes can contribute to an increased home resale value over time. A recent study found that solar systems added on average $5.50 per watt to a home's value above the cost of a comparable, non-solar home.