A device that reduces heat loss at night and during cloudy periods and heat gain during the day in warm weather. A movable insulator could be an insulative shade, shutter panel, or curtain.

The ratio of power produced by a wind energy conversion device to the power in a reference area of the free windstream.

The amount of fuel necessary to generate one kilowatt-hour of electricity.

Glass, plastic panels, or plastic sheets that reduce air infiltration and some heat loss when attached to either the interior or exterior of existing windows.

Transmit high-voltage electricity from the transformer to the electric distribution system.

A popular term for highly insulating window with a heat loss so low it performs better than an insulated wall in winter, since the sunlight that it admits is greater than its heat loss over a 24 hour period.

The volume of a unit weight of a substance at a specific temperature and pressure.

The physical material upon which a photovoltaic cell is applied.

A solar energy system that produces electricity with a PV module, and collects thermal energy from the module for heating. There are no commercially available systems available (as of 11/97).

The process of modifying a building's structure.

ICS solar systems are also called "batch" or "breadbox" water heaters. They combine the collector and storage tank in one unit. The sun shining into the collector strikes the storage tank directly, heating the water. The large thermal mass of the water, p ...

A type of High-Intensity Discharge (HID) lamp that uses sodium under high pressure as the primary light-producing element. These high efficiency lights produce a golden white color and are used for interior industrial applications, such as in warehouses a ...

A water heater that releases hot water from the top of the tank when a hot water tap is opened. To replace that hot water, cold water enters the bottom of the tank to ensure a full tank.

The water content of a substance (a solid fuel) as measured under specified conditions being the: Dry Basis, which equals the weight of the wet sample minus the weight of a (bone) dry sample divided by the weight of the dry sample times 100 (to get percen ...

As defined by the Comprehensive National Energy Act of 1992 (or the Energy Policy Act; EPAct): any organic matter from a plant which is planted for the exclusive purpose of being used to produce energy." This does not include wood or agricultural wastes o ...

Methyl Tertiary Butyl Ether (MTBE) is an ether compound used as a gasoline blending component to raise the oxygen content of gasoline. MTBE is made by combining isobutylene (from various refining and chemical processes) and methanol (usually made from nat ...

The gaseous byproducts of the combustion of a fuel.

Fuels formed in the ground from the remains of dead plants and animals. It takes millions of years to form fossil fuels. Oil, natural gas, and coal are fossil fuels.

A solar energy collection device consisting of containers of water located on a roof that absorb solar energy during the day so that the heat can be used at night or that cools a building by evaporation at night.

The device that reduces the pressure of liquid refrigerant thereby cooling it before it enters the evaporator coil in a heat pump.