The sun is a powerful star. It supplies us with energy, through a process called nuclear fusion, and sustains life on our planet Earth. Solar energy, or energy from the sun, has existed since prehistoric times when men would magnify the sun's energy in efforts to start fires.



The sun is a valuable resource that radiates enough energy on the United States in one day to meet the nation's needs for one and a half years. Since it is a free, clean and renewable source of energy, it is an energy source that will play a vital role in our future.

Using the sun's energy for our energy source seems like an easy solution to having an energy supply forever. Harnessing the suns energy is where the problem lies. The sun's rays shine all over the world and not in just one spot. Although it takes only 8 minutes for sunlight to travel to the earth, trying to catch the rays over such a wide area can prove to be tricky. Also, the energy in any one given place will vary due to factors, such as, clouds and weather conditions.

The history of using solar energy began in 1890's when solar water heaters were used in the United States. Solar water heating requires a storage collector and a storage tank. Flat plate solar collectors are mounted on rooftops. Pipes carrying water are pumped through these collectors. The tubes are painted black so they will get hot quicker. As the heat is collected the fluid in the tubes get heated. A storage tank holds the hot liquid. This helps with central heating and cutting fuel costs. Solar heaters became popular when natural gas was expensive and burning wood and coals were burdensome. It's popularity diminished with the discovery of an abundance of natural gas and oil deposits. Now they are making a comeback to replace the depleting fossil fuels that had taken its place.

Solar energy can be in the form of heat energy or light energy. The technology of photovoltaic, or PV as it is commonly called, converts the suns energy into electric currents through the use of solar cells. These electric currents can be used instantaneously or stored for later use. The PV cells consist of pieces of silicon under a thin piece of glass. They have both a positive and negative charge. Simple examples of this are the solar powered calculators that are common today. More complex examples are solar panels placed on roofs. This consists of using thin film solar cells as rooftop shingles, roof tiles, and even glazing for skylights. Unfortunately, the cells generate only about one sixth of the sun's energy into electricity. This means bigger arrays are needed and along with this come larger costs.

Solar thermal power plants use the sun to heat fluid, which in turn, is transferred into steam similar to fossil fuel burning plants. The steam is transformed into mechanical energy in a turbine and electrical energy from a generator. The downfall is solar plants cannot produce energy on cloudy days.

It is expected the next few years will see millions of households using solar energy. As research continues and processes improve, using our sun as a renewable energy source will produce efficiency and cost savings. So, let the sun shine in and take full advantage of this warm energy source where you live.