Glossary of Terms


AC Power

AC is short for alternating current and is the usual way by which electricity is delivered to residential and industrial locations. With the use of higher voltage, the transmission of power becomes significantly efficient.


Also known as ampere, it is a unit of electric current or amount of electric charge per unit time in coulombs per second. In a practical household wiring terms, it is the measurement of the number of electrons passing through a given point in one-second intervals.

DC Power

Short for direct current, it is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, and solar cells. In direct current, the electric charges flow in a constant direction.

Electrical Load

An electric circuit connected to an output terminal.  Electrical load affects the performance of circuits that output voltages or currents.  A power outlet is an example of voltage source, outputting 120 VAC (volts alternating current).

Electrical Panel

A component of an electricity supply system which divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit in a common enclosure. This device is also most commonly known as a breaker panel, fuse box or load center.


An electrical device which is designed to convert direct current (DC) into alternating current (AC). The resulting AC can be at any required voltage or frequency. It is so named because early mechanical AC to DC converters were made to work in reverse order and thus were "inverted" to convert DC to AC. The inverter performs the opposite function of a rectifier.


1,000 watts = 1 kW (kilowatt). It is used to state the power output of engines and the power consumption of tools and machines. A kilowatt is approximately equivalent to 1.34 horsepower. An electric heater with one heating element might use 1 kilowatt.


Photo – meaning light and voltaic – referring to electricity. Photons sent from the sun are absorbed by the panels and converted to electricity.

Solar Cells

A device that converts solar energy into electricity by the photovoltaic effect. Assemblies of cells are used to make solar panels, solar modules, or photovoltaic arrays. These cells convert the photons sent from the sun into electrons, leading to the production of electricity.

Solar Panels

A photovoltaic (electrons are emitted form matter after the absorption of energy from electromagnetic radiation such as x-rays or visible light) device that turns the energy of the sun into electricity.

Time of use

If the utility charges consumers more during a specific season and time of day, they are by law required to credit the same rates to individuals that are generating electricity through solar panels. Customers will be credited accordingly in line with utility's pricing.

Utility Grid

Electrical power transmission is the bulk transfer of electrical power. A power transmission network typically connects power plants to multiple substations near populated areas.

Utility Meter

Metering device used to measure the units of electricity, gas, and water. In this case, it is most commonly known as an electric meter that measures the amount of electrical energy supplied to or produced by a residence, business, or a specific machine.


The difference of electrical potential between two points of an electrical or electronic circuit expressed in volts. It is the measurement of the potential for an electric field to cause an electric current in an electrical conductor.


Watts are units of power. It measures a rate of energy conversion. A typical household incandescent light bulb uses electrical energy at a rate of 25 to 100 watts.