Photovoltaic Basics A photovoltaic cell, also called a solar cell or PV, is the technology used to convert solar energy directly into electrical power and is the basic building block of a photovoltaic system. Individual cells can vary in size from about 0.5 inches to about 4 inches across. To increase power output, cells are electrically connected into a packaged weatherproof module which can be further connected to form an array. These can be combined to form PV arrays of different sizes which make up the major part of the PV system. The simplest PV array consists of flat-plate PV panels in a fixed position. The advantages of fixed array systems are that they don't have moving parts and they are relatively lightweight making them suitable for many locations, including most residential roofs. Home PV systems are generally comprised of photovoltaic cells, devices that convert light energy directly into electricity, and inverters that convert the direct current from the photovoltaic into alternating current used in homes. This system is usually everything needed to meet a particular energy demand, such as powering a water pump, the appliances and lights in a home. Commonly systems are utility interconnected or grid-tied systems. These systems use electricity generated from the sun and electricity provided by an electric company. Homeowners can supplement their energy needs with electricity from their local utility when needed and can export excess electricity back to their local utility when their PV system is generating more energy than is needed. Build your solar panel for less than $100. Get detailed plans with easy to follow instructions at Earth4Energy. Off Grid Energies Home