How Does Solar Energy Work
The sun's energy is clean, endless and free. There is enough energy from the sun to power the entire earth forever. When the sun's light shines on an object, the energy creates heat. When the light shines on certain materials it turns into an electrical current. We can then harness this current and turn it into power. Large crystals made from silicon produce electrical current when the sun shines on them. These crystals work very well in the conversion but they are very expensive and hard to grow. Copper-indium-gallium-selenide is a smaller, less expensive crystal that can be formed into a film. However, they don't work as well at converting the light into electricity as the silicon crystals. Solar energy is not widely used because it is so expensive but research is being done every day to find new ways to use the sun's light for our electricity.
Solar Landscaping Lights
Inside a solar yard light are some basic parts. The part closest to the surface is the solar cells. Most yard lights have 4 solar cells that are wired in a sequence. Under that there is a NiCad battery, a control panel and an LED light. There is also a photoresistor that allows the light to know when it's dark. The solar cells are wired to a diode and then to an AA NiCad battery. The diode keeps the energy in the battery. During sunlight hours the solar cells charge the battery. When there is no sunlight when the solar cell stops giving energy and the photoresistor detects the darkness and turns on the LED light. The battery powers the light until it runs out of energy and is recharged by the next sunlight. Some solar lights use a small halogen light bulb that comes on for a short time when movement is detected. They have a motion sensor installed in them.
Other Things That Use Solar Power
Solar lighting is still a little on the expensive side. Each yard light is between $10 and $20. However, they are much easier to install because there are no wires or electricity needed. There are much larger lights that use solar energy. Many parking lots use solar panels to run their lights. The principle is the same for the lawn lights just on a much larger scale. There are many things that use solar energy such as some calculators, buoys and road signs. Even satellites use solar power. They store the energy while on the sunny side of the earth and use the power while on the dark side. Hopefully, sometime in the near future we'll all be using more solar power.