Acronym for American Society of Heating, Refrigerating and Air- Conditioning Engineers.

A long slender tube that holds fissionable material (fuel) for nuclear reactor use. Fuel rods are assembled into bundles called fuel elements or assemblies, which are loaded individually into the reactor core.

The total amount of solar radiation (direct, diffuse, and reflected) striking a surface exposed to the sky.

Energy which is not obtained from depletable energy sources. [See California Code of Regulations, Title 24, Section 2-5302]

Degree of hotness or coldness measured on one of several arbitrary scales based on some observable phenomenon (such as the expansion).

The ratio of the radiation absorbed by a surface to the total energy falling on that surface described as a percentage.

A charge paid by all market participants withdrawing energy from the ISO controlled grid. The access charge will recover the portion of a utility's transmission revenue requirement not recovered through the variable usage charge.

Solar radiation used by special equipment to provide space heating, hot water or electricity.

A system designed to convert solar radiation into usable energy for space, water heating, or other uses. It requires a mechanical device, usually a pump or fan, to collect the sun's energy.

A standard rating term that was used to rate the efficiency of heat pumps in California. ACOP was replaced by Heating Seasonal Performance Factor (HSPF) in 1988.