| It is no secret that the sun can be harnessed to | | | | burning wood and coals were burdensome. It's |
| provide a source of energy for homes and | | | | popularity diminished with the discovery of an |
| businesses. | | | | abundance of natural gas and oil deposits. Now they |
| The sun is a powerful star. It supplies us with energy, | | | | are making a comeback to replace the depleting fossil |
| through a process called nuclear fusion, and sustains | | | | fuels that had taken its place. |
| life on our planet Earth. Solar energy, or energy from | | | | Solar energy can be in the form of heat energy or |
| the sun, has existed since prehistoric times when | | | | light energy. The technology of photovoltaic, or PV |
| men would magnify the sun's energy in efforts to | | | | as it is commonly called, converts the suns energy |
| start fires. | | | | into electric currents through the use of solar cells. |
| The sun is a valuable resource that radiates enough | | | | These electric currents can be used instantaneously |
| energy on the United States in one day to meet the | | | | or stored for later use. The PV cells consist of pieces |
| nation's needs for one and a half years. Since it is a | | | | of silicon under a thin piece of glass. They have both |
| free, clean and renewable source of energy, it is an | | | | a positive and negative charge. Simple examples of |
| energy source that will play a vital role in our future. | | | | this are the solar powered calculators that are |
| Using the sun's energy for our energy source seems | | | | common today. More complex examples are solar |
| like an easy solution to having an energy supply | | | | panels placed on roofs. This consists of using thin film |
| forever. Harnessing the suns energy is where the | | | | solar cells as rooftop shingles, roof tiles, and even |
| problem lies. The sun's rays shine all over the world | | | | glazing for skylights. Unfortunately, the cells generate |
| and not in just one spot. Although it takes only 8 | | | | only about one sixth of the sun's energy into |
| minutes for sunlight to travel to the earth, trying to | | | | electricity. This means bigger arrays are needed and |
| catch the rays over such a wide area can prove to | | | | along with this come larger costs. |
| be tricky. Also, the energy in any one given place will | | | | Solar thermal power plants use the sun to heat fluid, |
| vary due to factors, such as, clouds and weather | | | | which in turn, is transferred into steam similar to fossil |
| conditions. | | | | fuel burning plants. The steam is transformed into |
| The history of using solar energy began in 1890's | | | | mechanical energy in a turbine and electrical energy |
| when solar water heaters were used in the United | | | | from a generator. The downfall is solar plants cannot |
| States. Solar water heating requires a storage | | | | produce energy on cloudy days. |
| collector and a storage tank. Flat plate solar collectors | | | | It is expected the next few years will see millions of |
| are mounted on rooftops. Pipes carrying water are | | | | households using solar energy. As research continues |
| pumped through these collectors. The tubes are | | | | and processes improve, using our sun as a renewable |
| painted black so they will get hot quicker. As the | | | | energy source will produce efficiency and cost |
| heat is collected the fluid in the tubes get heated. A | | | | savings. So, let the sun shine in and take full |
| storage tank holds the hot liquid. This helps with | | | | advantage of this warm energy source where you |
| central heating and cutting fuel costs. Solar heaters | | | | live. |
| became popular when natural gas was expensive and | | | | |