Solar PV System Array: a group of “solar modules” wired together. A mechanically integrated assembly of modules or panels with a support structure and foundation, tracker, and other components, as required, to form a direct-current power-producing unit.
The performance of photovoltaics is measured in terms of their efficiency at turning light into electricity. Most modern PV cells have a conversion rate of about 15%, so about one-sixth of the sunlight hitting the cell is converted into power. Creating higher efficiency ratios for PV cells has been a subject of continuing research.
Photovoltaic (PV) cells that convert sunlight directly into electricity. These are the solar panels that are often used to power satellites, calculators, and highway warning lights.
PV cells are made of silicon semiconductors similar to those used in computer chips. When sunlight hits these materials, it knocks electrons loose from their atoms, which flow through the material to produce electricity.
PV cells are frequently built into PV panels that hold about 40 cells, mounted into frames that are usually about 2 x 4 feet. These panels are set up on unobstructed south facing roofs or spaces with maximum solar gain. Their output can be increased with the use of mechanical tracking devices that follow the path of the sun across the sky during daylight hours.
Depending on need, 10 or more PV panels can provide enough power for a typical residence; for larger applications, such as electric utility generation or industrial purposes, any number of panels can be connected to form a single large system.
Grid-Tied Systems are the most common solar electric systems. They are installed on homes and businesses where the electricity grid is available. They interface seamlessly with the electricity grid, allowing excess power that is produced from the sun during the day to be sold back to the utility company. When this happens, your electric meter spins backwards to give you retail credit for the electricity you produced. (Namaste Solar) Also referred to as ‘utility interactive systems.’
Off-Grid Systems: people are considered to live ‘off-the-grid’ when they are living self-sufficiently without relying on any public or private energy provider or utility. Also referred to as a “stand-alone systems.”