Glossary
Alternating current: An electric current that reverses
directions at regular intervals (typically 60 times a second);
abbreviated "AC." This current is found in homes.
Circuit: A complete or partial path followed by a flow
of electric current.
Conductor: A substance or material that allows
electrons, or electrical current, to flow through it.
Current: The flow of electricity through a conductor.
Direct current: An electric current flowing in only one
direction; abbreviated "DC".
Electro magnetic fields: Invisible force fields that
surround the movement of electricity.
Fuel cell: A device in which a fuel, such as hydrogen
gas, is combined with oxygen to produce electricity, water and heat.
Generator: A machine for producing electrical current
when rotated by an external driver such as a turbine.
Grid: A system of interconnected power lines and
generators that is managed so that the generators are dispatched as
needed to meet the requirements of the customers connected to the grid
at various points.
Ground: A connection from an electrical circuit to the
earth.
Kilowatt (kW): A unit for measuring electrical energy.
1,000 watts = 1 kilowatt.
Kilowatt hour (kWh): The use of 1,000 watts of
electricity for one full hour.
Load: The power output of a generator or power plant.
Also, the resistance of a device to which power is delivered.
Megawatt: One million watts or 1,000 kW.
Meter: An instrument that records or regulates the
amount of something passing through it, like electricity, water or gas.
Switch: A device for connecting, breaking or changing
the connections in an electrical circuit.
Transformer: A device that raises or lowers the voltage
or force of AC electricity.
Turbine-generator: A machine in which the energy of a
moving fluid, such as water or steam, is converted to mechanical power
that drives an electric generator.
Volt: A unit for measuring the force used to produce an
electric current; the push or force that moves electric current through
a conductor.
Watt: A unit for measuring electric power. 1 kilowatt =
1,000 watts. 1 Megawatt = 1,000,000 watts.