Solar Terms

    CI.SL.DG. Solar Terms ERL 1

    We’ve all heard the words “solar “and “energy.” But, when you put these two words together, do you really know what it means? What, exactly, is solar energy? And, it doesn’t just end there. There are a lot of words that fall under the overall purpose and reasons behind solar energy.

    Knowing some of the commonly-used industry terms can help bring some clarity to the topic. IGS has composed a list of important terms to help you better navigate and understand the concept of solar energy and what it can—and should—mean to you:  

    Cell (battery):

    A single unit of an electrochemical device capable of producing direct voltage by converting chemical energy into electrical energy. A battery usually consists of several cells electrically connected together to product higher voltages.

    Conversion efficiency:

    The ratio of the electric power produced by a photovoltaic device to the power of the sunlight incident on the device.

    Gigawatt (GW):

    A unit of power equal to 1 billion watts, 1 million kilowatts, or 1000 megawatts.

    Kilowatt (kW):

    A standard unit of electrical power equal to 1000 watts, or to the energy consumption at a rate of 1000 joules per second.

    Kilowatt-hour (kWh):

    1000 thousand watts acting over a period of one hour. The kWh is a unit of energy; 1 kWh = 3600 kilojoules (kJ).

    Net metering:

    Allows the solar electric system to send excess electricity back through the electric meter to the utility. Your utility will bill you for the net (kWh used – kWh generated), and will in most cases carry forward a credit toward your next bill for the excess.


    A particle of light that acts as an individual unit of energy.

    Photovoltaic (PV):

    Pertaining to the direct conversion of light into electricity.

    Photovoltaic (PV) system:

    A complete set of components for converting sunlight into electricity by the photovoltaic process, including the array and balance of system components.

    Power Purchase Agreement (PPA):

    A type of solar contract where monthly payments are based on the system’s production level.

    Solar cooling:

    The use of solar thermal energy or solar electricity to power a cooling appliance. Photovoltaic systems can power evaporative coolers, heat-pumps and air conditioners.

    Solar energy:

    Electromagnetic radiation transmitted from the sun (solar radiation). The amount that reaches the earth is equal to one billionth of total solar energy generated, or the equivalent of about 420 trillion kilowatt-hours.

    Stand-alone system:

    An autonomous or hybrid photovoltaic system not connected to a grid. This system may or may not have storage, but most stand-alone systems require batteries or some other form of storage.

    Tilt angle:

    The angle at which a photovoltaic array is set to face the sun relative to a horizontal position. The tilt can be set or adjusted to maximize seasonal or annual energy collection.

    Learn even more about solar energy, here!