Photovoltaics (PV) or solar cells are semiconductor devices that convert sunlight into DC electricity. Groups of PV cells are connected into modules and arrays. The silicon used to produce crystalline PV modules is derived from sand. In order to produce the photovoltaic effect, the silicon must be intrinsic (pure), and then doped (addition of impurities) to form a semiconductor. There are two basic types of semiconductors, they are the N-Type and the P-Type. The PN junction is the building block of all electronic devices, integrated circuits, and microprocessors.
Since the sun is not always available, but the need for electricity usually is, solar panels are commonly used in conjunction with batteries. Batteries are currently the most cost effective storage option. There is another solution that is very promising for the future that uses hydrogen as a form of storage. Fuel cells can be used to separate the hydrogen and oxygen from water in a process called electrolysis. Basically the direct current from the solar panels along with water are fed into the fuel cell. The cell outputs hydrogen. The hydrogen is then compressed into a storage tank. The hydrogen can be used as an energy source by feeding it along with oxygen into a fuel cell, creating direct electrical current. The exhaust of a fuel cell when it is creating electricity is pure water. The water can be collected and used to make more hydrogen, starting the process again.
This site is maintained by the Electronics Engineering Department at Cape Fear Community College in Wilmington, North Carolina.