Energy Saving

The term solar energy refers to radiant energy that comes to the earth in the form of rays from the sun. The sun produces a vast amount of energy -- in one second, it radiates more energy than has been used by people since the beginning of time. This energy can be harnessed and used to provide heat and electricity. Solar energy is a clean power source that doesn't pollute the environment. It's freely available and is one of the most promising alternative energy sources for the future.

Solar energy is a completely renewable energy resource and is the most available source of energy, capable of satisfying current energy demands many times over. Energy from the sun is an intermittent power source, which means that it's not available at all times in all places. When the sun is hidden, there are no rays to provide radiant energy. This problem can be solved with thermal energy storage, which stores power in the form of heat to be used at times when the sun is not shining.

The Solar Energy Industry

Some large-scale solar power plants use mirrors to reflect sun rays onto receivers that convert the radiant energy to heat. A steam turbine or generator is then used to convert the resulting thermal energy into electricity. These plants are known as concentrating solar thermal plants. The world's largest of this type of solar plant are located in California's Mojave Desert.


Another type of solar generating technology converts sunlight into electricity directly using photovoltaic (PV) cells. PV cells are made of the same material as semiconductors in computers and are used in a wide range of applications, from watch batteries to power plants. There are several large PV power plants in Europe, including locations in Portugal and Germany.

Solar energy is a clean power source that doesn't pollute the environment.

Many homes today use solar PV systems for heating and electrical power. The power generated can be used to replace electricity normally purchased from a utility company. When the power generated exceeds the home's requirements, the unused energy can be sold back to the power company for credit.

Harnessing the Power of Solar Energy

According to the U.S. Department of Energy, covering just 4% of the world's deserts with PV cells (an area roughly the size of the Gobi Desert) could satisfy the energy demands of the entire earth. Solar energy currently is used to create less than 1% of the world's electricity, but estimates that by 2040 that number will grow to 26%. This growth will occur as solar-generated electricity becomes more cost effective throughout the world.

Solar energy holds the promise of a solution for future fossil fuel shortages, as well as fulfilling requirements for environmentally sustainable energy. The emerging solar energy technologies of today hold the promise of a nearly limitless supply of future energy from the sun.