Solar collector thermal performance ratings based on collector efficiencies, usually expressed in Btu per hour for solar collectors under standard test or operating conditions for solar radiation intensity, inlet working fluid temperatures, and ambient te ...

The ratio of fuel energy input as heat per unit of net work output; a measure of a power plant thermal efficiency, generally expressed as Btu per net kilowatt-hour.

An electricity generating facility that uses geothermal energy.

The minimum temperature at which combustion of a solid or fluid can occur.

This is a national organization dedicated to representing the interests of cooperative electric utilities and the consumers they serve. Members come from the 46 states that have an electric distribution cooperative.

A measure of the average amount of a specified pollutant or material emitted for a specific type of fuel or process.

A heating system that uses only outside air for combustion and vents combustion gases directly to the outdoors. These systems are less likely to backdraft and to negatively affect indoor air quality.

Energy produced by the conversion of biomass directly to heat or to a liquid or gas that can be converted to energy.

The rate of heat flow required to maintain a specific indoor temperature; usually measured in Btu per hour.

Energy output from a system that equals energy input.

The ratio of the percentage change in the quantity of a good or service demanded to the percentage change in the price.

A device or media that absorbs heat for storage for later use.

The change in direction of a ray of light when it passes through one media to another with differing optical densities.

The generation of an electric current, when two conductors of different metals are joined at their ends to form a circuit, with the two junctions kept at different temperatures.

The area of glass that fits in the window frame.

The process of producing electricity by transforming other forms or sources of energy into electrical energy; measured in kilowatt-hours.

Material such as brick, rock, or stone.

Power generated by a utility unit that operates at a very low capacity factor; generally used to meet short-lived and variable high demand periods.

A lamp where the light beam is focused 2 inches ahead of the lamp reducing the amount of light trapped in the fixture.

Those privately or publicly owned establishments that generate, transmit, distribute, or sell electricity.