Solar radiation reflected from the ground onto a solar collector.

The vacancy where an electron would normally exist in a solid; behaves like a positively charged particle.

The amount of money required to secure a specified cash flow at a future date at a specified return.

The highest possible pressure in a fuel-air mixture before spontaneous ignition occurs.

A vehicle with an engine capable of operating on two different types of fuels.

A stationary or rotating vent used to ventilate attics or cathedral ceilings; usually made of galvanized steel, or polypropylene.

An electric current taking a shorter or different path than intended.

Any wholly or partially enclosed space in which combustion takes place.

A body of water that contains brackish (highly saline) water that forms layers of differing salinity (stratifies) that absorb and trap solar energy. Solar ponds can be used to provide heat for industrial or agricultural processes, building heating and coo ...

A curve that displays load values on the horizontal axis in descending order of magnitude against the percent of time (on the vertical axis) that the load values are exceeded.

Turning off or disconnecting loads to limit peak demand.

The local climate of specific place or habitat, as influenced by landscape features.

The demand of a consumer of electricity at the time of a power supplier's peak system demand.

Air that is returned to a heating or cooling appliance from a heated or cooled space.

Amorphous silicon with a small amount of incorporated hydrogen. The hydrogen neutralizes dangling bonds in the amorphous silicon, allowing charge carriers to flow more freely.

The part of an energy utility's charge based on actual energy consumed by the customer; the product of the kilowatt-hour rate and the total kilowatt-hours consumed.

A gasifier in which the feedstock (fuel) is suspended by the movement of gas to move it through the gasifier.

The device in an air conditioner or heat pump in which the refrigerant condenses from a gas to a liquid when it is depressurized or cooled.

The number of revolutions that the motor turns in a given time period (i.e. revolutions per minute, rpm).

A type of furnace in which fuel is burned and the heat is used to produce steam.