Sunday, October 16, 2011
What is Solar Energy ?
During photovoltaic conversion, solar energy is collected through panels, called solar panels. Solar panels are covered with large modules which are covered with lots of little PV cells, or photovoltaic cells. The PV cells collect the light from the sun. Once the light is inside a PV cell. A photon is a particle of solar energy. Within the semiconductor, energy of the photons shifts to the electrons. This energizes the electrons. Then the electrons break out of the semiconductor to get to the silicone atoms. Then they flow into the electric current. Usually a solar cell is made of a glass protective layer, an anti-reflective coat, and electric contacts. We use PV cell systems every day. Common tools like watches and calculators are powered with PV systems. Look at the top of a calculator. Do you see the little squares at the top? Those are lots of little PV cells. Usually PV cells don’t generate much electricity. PV cells generate about ½ a volt per square decimeter. A solar panel making fifty watts of electricity is about four decimeters by ten decimeters. What if you don’t know how much energy your appliance or machine needs? Well, the answer is easy.