Albedo – Ratio of light reflected from a surface.
Alternating Current (AC) – An electric current that reverses direction at regular intervals.
Altitude – Height of the sun above the horizon.
Ampere (amp) – Unit of electric current (refers to flow of current); one ampere corresponds to a certain number of electrons passing a fixed point each second.
Array – Photo-voltaic modules connected together to provide a single electrical output.
Azimuth – Horizontal angle measured clockwise in degrees from a reference direction, usually the north or south point of the horizon, to the point on the horizon intersected by the object’s line of altitude.
Cell – Basic unit of a photo-voltaic panel.
Diffuse Insolation – Solar radiance that is scattered or reflected by atmospheric components, such as clouds, dust, etc.
Direct Current (DC) – An electric current in which electrons flow in one direction only.
Direct Insolation – Solar radiance that directly hits the earth’s surface.
Electrical Efficiency – Useful power output divided by the total electrical power consumed.
Electric Circuit – Complete path of an electric current, including the generating apparatus, intervening resistors, or capacitors.
Electric Current – Rate of flow of electric charge, measured in amperes.
Electrical Grid – Interconnected network for distributing electricity.
Energy – Any source of usable power, as fossil fuel, electricity, or solar radiation.
Gigawatt (GW) – 1,000,000,000 watts.
Insolation – Measure of solar radiation energy received on a given surface area in a given time.
Inverter – Device that converts DC electricity into AC electricity.
Junction Box – Protected enclosure for electrical wiring.
Kilowatt (kW) – 1,000 watts.
Kilowatt-hour (kWh) – Measure of kilowatt production of power in kilowatts and time in hours.
Load (noun) – (1) The power consumed on an electrical circuit. (2) A power-absorbing device, such as a blender, light bulb, etc.
Load (verb) – To add a power-absorbing device to an electrical circuit .
Megawatt (MW) – 1,000,000 watts.
Module – Interconnected assembly of solar cells; also called a panel.
Monocrystalline – Single silicon crystal; monocrystalline panels are made from one large, single silicon crystal making it rated the most efficient solar technology available.
Ohm – Unit of electrical resistance.
Photovoltaic (PV) – Technology and research that relates to the application of solar cells for energy by converting radiant energy directly to electricity.
Photo-voltaic Efficiency – The ratio of power produced by a solar cell at any instant to the power of radiant energy striking the cell; certain factors such as temperature can cause the efficiency rate to vary during the day.
Photo-voltaic System – A system which uses solar cells to convert light into electricity; consists of multiple components, including solar cells, mechanical and electrical connections and mountings and means of regulating and/or modifying the electrical output.
Polycrystalline Cell – Solar cells produced from processed liquid silicon; when solidified, multiple silicon crystals are formed. Less efficient than monocrystalline cells.
Radiance – Light from the sun; also called solar radiance.
Remote System – Photo-voltaic system not connected to the utility grid.
Silicon – A chemical element from which semiconductors are made.
Solar – (1) Of or pertaining to the sun. (2) Utilizing, operated by, or depending on solar energy. (3) Manufacturing or providing solar power.
Solar Constant – The average density of solar radiation measured outside Earth’s atmosphere and at Earth’s mean distance from the sun, equal to 0.140 watt per square centimeter.
Solar Energy – Energy derived from the sun in the form of solar radiation.
Solar Power – Energy from the sun that is converted into thermal or electrical energy.
Solar Spectrum – Distribution of energy emitted by the sun arranged in order of wavelengths.
Solar Thermal – Method of harnessing solar energy for thermal energy (heat).
Thin Film – A thin layer of semiconductor material, such as amorphous silicon, which is deposited directly onto a plate of glass. Least efficient of all solar cells.
Tracking Array – A solar array that follows the path of the sun to maximize the solar radiation incident on the photovoltaic surface.
Transformer – A device used to transfer electrical energy from one circuit to another; with an alternating current, a transformer will either raise or lower the voltage as it makes the transfer.
Volt (V) – Standard unit of voltage; one volt produces one ampere of current when acting a resistance of one ohm.
Voltage – Potential energy that makes the electrical current flow in a circuit by pushing the electrons around (pressure).
Watt (W) – The unit of electric power, or amount of work (J), done in a unit of time. One ampere of current flowing at a potential of one volt produces one watt of power.
