A way of joining photovoltaic cells or modules by connecting positive leads together and negative leads together; such a configuration increases the current, but not the voltage.

A device that uses electronic components to regulate the voltage of fluorescent lamps.

A structure or media that absorbs heat.

A component of a water heating system that opens at a designated temperature or pressure to prevent a possible tank, radiator, or delivery pipe rupture.

Any material that has a limited capacity for conducting an electric current. Certain semiconductors, including silicon, gallium arsenide, copper indium diselenide, and cadmium telluride, are uniquely suited to the photovoltaic conversion process.

A solar energy concentrating technology that uses a linear receiver that tracks the focal area of a reflector or array of reflectors.

The replacement of a non-functional or ineffective lamp with a new, more efficient lamp.

The difference between the total cooling effect and the dehumidifying effect.

For valves and fittings, implies that they are suitable for working pressures between 125 to 175 pounds per square inch.

The heat-transfer (exchanger) component of a heatpump, located outdoors, from which heat is collected in the heating mode, or expelled in the cooling mode.

The compound (working fluid) used in air conditioners, heat pumps, and refrigerators to transfer heat into or out of an interior space. This fluid boils at a very low temperature enabling it to evaporate and absorb heat.

Space cooling achieved by shading, natural (unassisted, as opposed to forced) ventilation, conduction control, radiation, and evaporation; also called passive cooling.

The maximum energy demand or load in a specified time period.

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

A wheel that is designed to use the weight and/or force of moving water to turn it, primarily to operate machinery or grind grain.

A product of crude oil that is used for space heating, diesel engines, and electrical generation.

The power output of a device under specific or nominal operating conditions.

An electrical device for converting alternating current to direct current. The chamber in a cooling device where water is separated from the working fluid (for example ammonia).

A heat exchanger in which heat is recovered from the products of combustion.

The loss of heat as the water circulates through a water heater tank and inlet and outlet pipes.