A measure of the moisture content of air; may be expressed as absolute, mixing ratio, saturation deficit, relative, or specific.

A power plant that produces electricity by the force of water falling through a hydro turbine that spins a generator.

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 temperature of the air as measured by a standard thermometer.

The relative extent that energy is required for a process.

A group of solar photovoltaic modules connected together.

An energy band in a semiconductor in which electrons can move freely in a solid, producing a net transport of charge.

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

The highest wind speed at which a wind turbine stops producing power.

Infrared or radiant heat.

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

Air that provides the necessary oxygen for complete, clean combustion and maximum heating value.

A cooling device that uses mechanical energy to produce chilled water.

Any liquid petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine. Domestic (residential) heating fuels are classed as Nos. 1, 2, 3; Industrial fuels as Nos. 4, 5, and 6.

A colorless, odorless, tasteless gas composed of one molecule of Carbon and four of hydrogen, which is highly flammable. It is the main constituent of "natural gas" that is formed naturally by methanogenic, anaerobic bacteria or can be manufactured, and w ...

In reference to solar thermal collectors, the condition where the heat transfer fluid is flowing through the collector loop under normal operating conditions.

Turning off or disconnecting loads to limit peak demand.

Pounds/force per square inch gauge.

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 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.