Alternating Current (AC)
Electrical current that reverses direction periodically, commonly used in residential and commercial electrical systems.
Amorphous Silicon
A type of solar cell made from a non-crystalline form of silicon.
Array
Solar arrays are groups of interconnected PV modules that produce energy. They are typically supported by mounts and can consist of a single module.
Azimuth
An azimuth is the angle between true south and the point in the horizon that is directly below the sun. Ideally, solar panels should face this direction.
Balance of System (BOS)
All components of a solar system excluding the solar panels, such as inverters, wiring, and mounts.
Ballast Mount
Most solar panel systems are supported by mounts that attach directly to a home's rafters. However, when it comes to flat roofs, solar technicians usually prefer using a ballast mount. This type of mount has weights that keep the solar panel array in place, eliminating the need for roof penetration.
Battery Backup
A system that stores excess solar energy in batteries for use when the solar panels are not generating electricity.
BOS
BOS stands for Balance of System. It refers to the collection of components necessary for a solar panel system to function properly and connect with the grid, and thus a utility. These components may include solar panels, wiring, switches, breakers, combiner boxes, monitoring equipment, a mounting system, and more. The equipment you need may vary slightly depending on whether you have roof-, ground-, or wall-mounted solar panels.
Capacity
The total amount of electricity a solar system can produce, usually measured in watts or kilowatts.
Charge Controller
A device that controls the charge going into and out of a battery in a solar power system.
Crystalline Silicon
A type of material used in the majority of solar cells, available in monocrystalline and polycrystalline forms.
Direct Current (DC)
Electrical current that flows in a single direction, generated by solar panels.
Efficiency
The ratio of electrical energy produced by the solar panels to the solar energy hitting the panels.
Electricity Grid
The grid is a network that transports electricity from power generators to homes and businesses. If you possess solar panels, you can link your system to the grid to make use of your utility's net metering program or to draw energy when rates are low. Additionally, you can depend on the grid if your panels failed to generate enough energy during the day to power your home.
Energy Audit
An assessment to determine how much energy a home uses and what measures can improve efficiency.
Energy Storage
Systems used to store energy, often in batteries, for later use.
Feed-in Tariff (FiT)
A policy where homeowners are paid for the excess electricity they generate and feed back into the grid.
Fixed Mount
A non-adjustable framework that holds solar panels in place.
Grid-Connected System
Hybrid solar panels connect to and disconnect from the grid as needed, allowing you to use both the panels and grid for power. You can even send excess energy back to the grid and benefit from net metering programs offered by your utility.
Grid-tied System
A solar system connected to the electrical grid, allowing homeowners to draw from or feed into the grid.
Ground Mount
Solar panel mounts that are placed on the ground rather than on a roof.
Inverter
A device that converts direct current (DC) to alternating current (AC) for use in the home.
Kilowatt (kW)
A unit of power equivalent to 1,000 watts.
Kilowatt-hour (kWh)
A unit of energy equivalent to one kilowatt of power used for one hour.
Megawatt (MW)
A unit of power equivalent to 1,000 kilowatts or 1 million watts.
Micro-Inverter
A small inverter for a single solar panel, often used in systems with shading issues.
Monocrystalline
A type of solar cell made from a single crystal structure.
Net Metering
A system that allows homeowners to receive credit for excess electricity generated by their solar system that is fed back into the grid.
Off-grid
A solar system not connected to the electrical grid, often using batteries for energy storage.
Photovoltaic (PV)
The technology used to convert sunlight into electricity.
Polycrystalline
A type of solar cell made from different crystal structures.
Power Purchase Agreement (PPA)
A financial agreement where a developer installs a solar system on a customer's property and the customer buys the electricity produced by the system at a fixed rate.
Renewable Energy Certificates (RECs)
Tradable commodities proving that certain electricity is generated using renewable energy sources.
Rooftop Solar
Solar panels installed on the roof of a building.
Solar Array
A collection of solar panels connected together.
Solar Cell
The basic unit that converts sunlight into electricity within a solar panel.
Solar Panel
A device that converts sunlight into electricity, made up of multiple solar cells.
Solar Thermal
A technology that uses sunlight to heat water or air for residential use.
String Inverter
An inverter that converts the DC electricity generated by a string (row) of solar panels into AC electricity.
Tracking Mount
A mount that moves solar panels to follow the sun, maximizing electricity production.
Transformer
A device that changes the voltage of alternating current electricity.
Utility-Scale Solar
Solar power plants primarily aimed at supplying electricity into the grid, not generally used for residential purposes.
Utility Grid
The larger electricity network to which a residential system may be connected.
Volt (V)
A unit of electric potential.
Voltage
The electric potential difference between two points in an electrical circuit.
Watt (W)
A unit of electrical power.
Wattage
The amount of electrical power, in watts, that a device uses or produces.
