Solar Terms

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Solar Terms

Glossary of Solar-Related Terms

AC – Alternating current. This is the type of electrical current that is typically used in buildings and in homes. It is supplied by your local utility.

Amorphous Silicon – A very thin layer of silicon that is deposited on a substrate (glass, metal or plastic) in a manner to create a photovoltaic (PV) module.

Ampere or amp – An electric current is measured in amperes or amps.

Amp Hours – The number of amps used or produced in a given hour. (Batteries are rated in amp hours).

Array – A group of photovoltaic (PV) or solar electric modules connected together in a power system. (Also see modules).

Battery Bank – A group of batteries wired together to store power in a solar electric system. Battery Banks use stored power at night, on cloudy days or to run more power than the array can produce at one time.

Biomass – A renewable form of energy that is derived from burning plant material that can be “renewed” by planting and growing again each year.

Building Integrated Photovoltaics (BIPV) – Photovoltaic (PV) modules that are integrated into a building’s structure.

Charge Controller – Regulates the current from solar panels to a battery bank. The charge controller ensures batteries are not over-charged and provides protection from the current running backwards to the solar panels.

CIGS – Acronym for the chemical compound Cu (In,Ga)Se₂. A thin film photovoltaic (PV) technology that utilizes Copper, Indium, Gallium and Selenium.

CO² – Carbon Dioxide, also believed by many scientists to be a major contributor to climate change.

Current – The rate of flow of an electric charge. Current is measured in amps.

DC – Direct current. Electrical energy flowing in one direction. This is the type of power that comes from photovoltaic (PV) technology and batteries.

Distributed Energy – Term used to describe energy produced by generating units that are close to the location of use. PV is the most flexible of distributed power sources.

Electrolyzer – A device used to breakdown water, utilizing electricity, into hydrogen and oxygen.

Fossil Fuel – Fuels that contain primarily carbon and hydrogen, including oil, coal, and natural gas, that result in CO²emissions when burned. Fossil Fuels are not renewable and when they run out, they are gone forever. (Also known as “hydro-carbons”).

Fuel Cell - A fuel cell is an electrochemical energy conversation device. It converts hydrogen and oxygen into water, producing electricity and heat in the process.

Gigawatt – One billion watts – 1,000,000,000 W.

Greenhouse Gas (GHG) – A gas that when released into the atmosphere, traps infrared radiation (heat) and causes a slow heating of the planet. CO2 is the most common GHG.

Grid – A network of electric power lines and connections that are controlled by utility companies.

Inverter – An appliance used to convert DC power into standard household AC current.

Kilowatt or KW – One thousand watts – 1,000 W.

Load – An appliance or fixture that consumes or uses the energy harvested or stored by the solar system.

Megawatt – One million watts – 1,000,000 W.

Module – A photovoltaic (PV) module is a panel consisting of many solar cells connected together in a series.

Net Metering – The process by which an on-site generator (such as photovoltaic (PV)) operating independently of the utility grid, can be interconnected to the grid. The electric meter will show the NET difference between what is generated on site to what is supplied by the grid.

Passive Solar - Technology that utilizes a structure to capture and store the sun’s heat. In a passive system, there are usually no moving parts (fans, pumps, etc.). The primary use for passive thermal technologies is in homes and buildings for space heating.

Photovoltaic – The process of converting light into electricity. Photo means "light", voltaic means "electric". Often referred to as “PV” and “solar-electric” for short.

Renewable Energy - Energy that is derived from sources that are not depletable. Examples would be: solar energy (solar-electric, solar-thermal), biomass, geothermal energy, wind energy, etc.

Rooftop PV – A method of deploying photovoltaics (PV) by installing panels on a home or business rooftop.

Solar Cell – The smallest basic solar-electric device, which generates electricity when exposed to light.

Solar Concentrator – A technology that concentrates the suns power into a smaller area.

Solar Electric – The term used to describe something which uses sunlight to produce electricity. Also referred to as "Photovoltaic".

Solar Farm – The term used to describe a facility where many photovoltaic (PV) systems are centrally located. The minimum size for a solar farm would be around one (1) megawatt.

Solar Heating - Utilizing the sun to generate thermal energy to heat a structure utilizing heated air or liquid, i.e. a swimming pool, a home, or a building.

Solar Shingle – A type of roofing material that incorporates photovoltaic (PV) cells directly into the shingle. This method for packaging solar cells leaves the roof appearing as if there was no PV installed at all.

Solar Thermal - Term used to describe heat (rather than electricity) that is generated by the sun. Examples would be solar swimming pool heaters and household domestic water heaters.

Silicon - The main material that is used in the current generation of photovoltaic (PV) cells. Current products are normally made of crystalline or polycrystalline silicon. Silicon wafers are typically 100-300 microns thick (one (1) micron = 1/1000 millimeter). They are very reliable, but are still considered expensive. Silicon is the same material from which most electronic devices are made, such as computer chips.

Thermal Blanket – A floating foam cover that insulates well, but does not allow light to pass through. Primarily used in swimming pools.

Thin Film PV – A solar-electric technology utilizing very thin layers of semiconductor materials, usually one to 10 microns. This type of device uses far less material than a conventional silicon photovoltaic (PV) panel.

Voltage or Volts – Voltage is the rating of the amount of electrical pressure that causes electricity to flow in the power line. If electricity were water, voltage would measure the amount of pressure at the faucet.

Watts – A watt is a measurement of total electrical power. Volts x amps = watts.

Watt-Hour – The quantity of electrical energy used or produced when one watt is used for one hour.

Wind Power - Wind power is a form of solar energy, created by circulation patterns in the Earth’s atmosphere that are driven by heat from the sun.