The process of photovoltaics produces clean renewable energy without pollution. This atomic level process of directly converting sunlight into electricity is very simple. Photovoltaic technology harnesses the sun’s energy using solar cells. The resulting DC current is then ready to be used or stored.
The photovoltaic effect occurs because of certain properties of semiconducting materials such as silicon, gallium arsenide, or copper sulfate. When a thin sample of semiconducting material is placed in sunlight, solar radiation causes electrons to be released and move freely inside the semiconductor material. The electron positions left open by the electrons escaping their atoms act as a positive charge. This attracts electrons from the opposite and negative side of the material. The side with the positive charge lacks electrons, while the negative side has an overabundance of electrons. This produces an inner electric field.
Solar cells are made from wafer thin pieces of semiconductor materials, such as silicon or gallium arsenide. These thin wafers form an electrical field that holds positive charge on one side and a negative charge on the other. Electrical conductor wires are attached to both sides of the silicon wafer, forming an electrical circuit. When these are placed in sunlight, light energy causes electrons to be freed from their atoms. Electrons are then captured in the form of electric current that can be used as an energy or power source. Individual solar cells are small, approximately 12 x 12 centimeters, but they are linked together inside solar panels. These solar panels are in turn linked together so that they work to produce electricity, for homes and solar farms.
How Photovoltaics Are Used In Buildings
Building Integrated Photovoltaics (BIPV) is a new concept in building design and construction that uses solar panels as the exterior surface of the building. Incorporating solar panels as part of the structure can be beautiful as well as practical. BIPV saves money and natural resources by replacing building materials, and by producing clean energy without fossil fuels. BIPV systems can interface with the utility grid or stand-alone off the grid.
Solar energy is renewable and free to use, once the system is set up to harness its power. Over time, solar energy saves money by reducing the cost of energy. Solar panels require little or no maintenance, do not pollute in any way, make no byproducts or waste, and are completely silent as they work. In some areas, solar energy can even provide income.
Solar energy panels do not produce energy at night, during storms, or on very overcast days. While electricity can be stored in batteries, there is a limit to storage. After many cloudy days, it may be necessary to use other sources of energy. Another disadvantage to solar energy is the initial cost.
There is a great deal of potential for solar energy technology and use. PETE, which is short for photon enhanced thermionic emissions, is only one of the many options being explored in connection with solar energy. PETE is a new way to use heat from the sun to create even more electricity. PETE is not superior to photovoltaics, which uses only light, but using both together doubles the yield of electricity. PETE and photovoltaics are ideal partners for a brighter future.