Solar Energy


Solar energy can play a key role in creating a clean, reliable energy future. The benefits are many and varied. Consumers who use these technologies will benefit directly and immediately. Using solar energy produces immediate environmental benefits. Electricity is often produced by burning fossil fuels such as oil, coal, and natural gas. The combustion of these fuels releases a variety of pollutants into the atmosphere, such as carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen oxide (NOx), which create acid rain and smog. Carbon dioxide from burning fossil fuels is a significant component of greenhouse gas emissions. These emissions could significantly alter the world’s environment and lead to the global warming predicted by most atmospheric scientists.

The combustion of fossil fuels releases more than 6 billion tons of carbon into the atmosphere each year. The United States alone is responsible for 23 percent of these emissions. Clean energy sources, such as solar energy, can help meet rising energy demands while reducing pollution and preventing damage to the environment and public health at the same time.

Solar energy is an excellent alternative to fossil fuels for many reasons:

  • It is clean energy. Even when the emissions related to solar cell manufacturing are counted, photovoltaic generation produces less than 15 percent of the carbon dioxide from a conventional coal-fired power plant. Using solar energy to replace the use of traditional fossil fuel energy sources can prevent the release of pollutants into the atmosphere.
  • Using solar energy to supply a million homes with energy would reduce CO2 emissions by 4.3 million tons per year, the equivalent of removing 850,000 cars from the road.
  • Solar energy uses fewer natural resources than conventional energy sources. Using energy from sunlight can replace the use of stored energy in natural resources such as petroleum, natural gas, and coal. Energy industry researchers estimate that the amount of land required for photovoltaic (PV) cells to produce enough electricity to meet all U.S. power needs is less than 60,000 square kilometers, or roughly 20 percent of the area of Arizona.
  • Solar energy is a renewable resource. Some scientists and industry experts estimate that renewable energy sources, such as solar, can supply up to half of the world’s energy demand in the next 50 years, even as energy needs continue to grow.


Solar is the Latin word for sun—a powerful source of energy that can be used to heat, cool, and light our homes and businesses. That’s because more energy from the sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of technologies convert sunlight to usable energy for buildings. The most commonly used solar technologies for homes and businesses are solar water heating, passive solar design for space heating and cooling, and solar photovoltaics for electricity.

Businesses and industry also use these technologies to diversify their energy sources, improve efficiency, and save money. Solar photovoltaic and concentrating solar power technologies are also being used by developers and utilities to produce electricity on a massive scale to power cities and small towns. Learn more about the following solar technologies:

Solar Photovoltaic Technology

Concentrating Solar Power

Solar Process Heat


Frequently Asked Questions :: Solar Water Heating

(source: EERE)

How do solar water heaters work?

What types of systems are suitable for homes?

What types of active solar-water heating systems are available?

What type of passive solar water heating systems are available?

How do I select a solar water heater?

How do I install and maintain a solar water heater?

What other ways can I improve water heating energy efficiency?

How can I protect a solar water heater from freezing?

What heat transfer fluids are used in solar water-heating systems?
Are there any disadvantages to using solar energy?
Do solar water-heating systems require a backup system?