Question

How does a PV panel work? How many PV panel systems are available?

Answer 1

Answer) A PV system is composed of one or more solar panels combined with an inverter, other electrical and mechanical hardware that use energy from the Sun to generate electricity. Solar panels comprise of many, smaller units called photo-voltaic cells( means they convert sunlight into electricity.) Many cells linked together make up a solar panel. A solar panel works by allowing photons, or particles of light, to knock electrons free from atoms, generating a flow of electricity. Each photo-voltaic cell is basically a sandwich made up of two slices of semi-conducting material, usually silicon. Photo-voltaic cells need to establish an electric field, to work. An electric field occurs when opposite charges are separated. This is done by doping silicon with other materials, giving each slice of the sandwich a positive or negative electrical charge.The manufacturers seed phosphorous into the top layer of silicon, which adds extra electrons, with a negative charge, to that layer and the  the bottom layer is given a dose of boron, which results in fewer electrons, or a positive charge. As a result, an electric field is formed at the junction between the silicon layers. When a photon of sunlight hits an electron free, the electric field will push that electron out of the silicon junction. A couple of other components of the cell turn these electrons into usable power. Metal conductive plates on the sides of the cell collect the electrons and transfer them to wires. At that point, the electrons can flow like any other source of electricity.Each panel produces a relatively small amount of energy. So, they are linked together with other panels to produce higher amounts of energy as a solar array. This array produces a DC electricity is in the form of direct current (DC). A solar inverter to converter is used to the output from direct to alternating current. As PV systems convert light directly into electricity, they are not to be confused with other solar technologies, such as concentrated solar power or solar thermal, used for heating and cooling.

PV systems range from small, rooftop-mounted or building-integrated systems with capacities from a few to several tens of kilowatts, to large utility-scale power stations of hundreds of megawatts. Nowadays, most PV systems are grid-connected, while off-grid or stand-alone systems account for a small portion of the market .Photo-voltaic systems are generally categorized into three distinct market segments: residential rooftop, commercial rooftop, and ground-mount utility-scale systems.