Solar Systems FAQ
What is photovoltaics (solar electricity), or "PV"?
What do we mean by photovoltaics? The word itself helps to explain how photovoltaic (PV) or solar electric technologies work. First used in about 1890, the word has two parts: photo, a stem derived from the Greek phos, which means light, and volt, a measurement unit named for Alessandro Volta (1745-1827), a pioneer in the study of electricity. So, photovoltaics could literally be translated as light-electricity. And that's just what photovoltaic materials and devices do; they convert light energy to electricity, as Edmond Becquerel and others discovered in the 18th Century.
What is the difference between a Solar Cell, Panel and Array?
Solar Cells are the small electrical devices that actually convert sunlight into electricity. Solar Panels are made up of all of these individual Solar Cells, wired together to produce a specified voltage and current. Sometimes the words "panel" and "module" are interchanged to describe the same thing. A group of panels wired together is called a Solar Array.
What does a Blocking Diode do?
A Blocking Diode can be thought of as a one-way valve that allows electrons to flow forwards, but not backwards. It is a semiconductor connected in series with a solar cell or cells and a storage battery to keep the battery from discharging through the cell when there is no output, or low output, from the solar cell.
What does "Load" mean?
LOAD Refers to equipment that is powered by electricity. Usually expressed in terms of amperes or watts. In an electrical circuit, any devise or appliance that uses power (light bulbs, motors,etc).
What is a Photon?
A Photon is a particle of light that acts as an individual unit of energy.
How does a solar panel generate electricity?
A solar panel generates electricity by the Photovoltaic (PV) Effect. This is the phenomenon that occurs when photons, the "particles" in a beam of light, knock electrons loose from the atoms they strike. When this property of light is combined with the properties of semiconductors, electrons flow in one direction across a junction, setting up a voltage. With the addition of circuitry, current will flow and electric power will be available.
What is Insolation?
Insolation is the solar power density incident on a surface of stated area and orientation,
usually expressed as Watts per square meter or Btu per square foot per hour.