About Solar Energy
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!
Solar is one of the fastest-growing industries in America, employing 120,000 workers and generating an estimated 13 gigawatts (GW) of clean electricity – enough to effectively power 2 million homes. Installed solar capacity continues to grow as the cost of going solar drops.
Benefits of Solar Energy
Creating electricity from sunlight instead of fossil fuels avoids the emission of greenhouse gases and other air pollutants and stimulates the economy.
- 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, so it can help avoid the carbon dioxide (CO2) and other air pollutant emissions associated with conventional electricity generation
- Renewable: It’s inexhaustible so it will never run out, unlike limited fossil fuel sources
- Limited land impact: Solar doesn’t require fossil fuel extraction, which damages the land
- Energy independence: Producing renewable energy at home supports a homegrown energy source, helping secure America’s energy future
- Demand creates supply: As more people install solar on their homes and businesses, the greater the demand will be for additional home solar systems and larger-scale solar farms
- Green job growth: Increased support for renewable energy development creates more employment opportunities in the green job sector, which helps to stimulate our economy
- Financial return: A solar energy system can instantly reduce your electric bill and provide a long-term fixed energy rate for the life of your system (20-25 years), which means cost savings now and protection against unpredictable electric prices in the future
- Plus, solar panels can increase a home’s resale value—one 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 home1
How It Works
There are two ways that sunlight can be converted to electricity:
1) Directly, as in the case of photovoltaic (PV) applications
- PV cells convert sunlight directly into electricity and are made of semiconductors such as crystalline silicon or various thin-film materials
- PV 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 form of solar energy generation – you might have seen them on homes and businesses in your neighborhood
- Photovoltaic solar panels absorb the sun’s rays and convert them into energy
- A control device converts the energy from direct current (DC) electricity to alternating current (AC) electricity, which is capable of powering electrical items
- This electricity can be added to the electricity grid, which powers local homes and businesses
2) Indirectly as in the case of solar thermal applications
- Solar thermal collectors capture heat from sunlight and use it in a variety of ways
- In most large utility scale solar facilities, high-temperature thermal collectors utilize mirrors or lenses to concentrate sunlight, collect its heat and convert the heat into electricity
- Low-temperature thermal collectors use heat directly for hot water or space heating for residential, commercial and industrial facilities
- Solar energy can be used to heat water; power cars, aircrafts, calculators and other small appliances; and even cook food
- Solar energy is the Earth’s most available energy resource because it can be found anywhere the sun shines
- It takes about 8 minutes for sunlight to travel from the sun to the earth, moving at 186,282 miles per second
- The largest solar power plant in the world is located in California’s Mojave Desert and is made up of 173,500 mirrors that convert the sun’s heat into electricity
- Solar produces about 0.2% of the energy used in the United States
1 Source: April 2011 report: “An Analysis of the Effects of Residential Photovoltaic Energy Systems on Home Sales Prices in California” by the Ernest Orlando Lawrence Berkeley National Laboratory (http://eetd.lbl.gov/ea/emp/reports/lbnl-4476e.pdf). The price premium for the average size installation in the study 3.1 kilowatts [kW]) was approximately $17,000.