A condition that results from an imbalance between the number of protons and the number of electrons in a substance.

An interior wall made of water filled containers for absorbing and storing solar energy.

The maximum heat output (in Btu per hour) released by a burner with a stable flame and satisfactory combustion.

An insulation product composed of loose fibers or fiber pellets that are blown into building cavities or attics using special pneumatic equipment.

A device that cools air by removing moisture from it.

Electromagnetic radiation in the wavelength range of 4 to 400 nanometers.

A term used for the transparent or translucent material in a window. This material (i.e. glass, plastic films, coated glass) is used for admitting solar energy and light through windows.

The maximum load that a motor is capable of supplying.

A combustion heating appliance that vents the combustion by-products directly into the heated space. The latest models have oxygen-sensors that shut off the unit when the oxygen level in the room falls below a safe level.

A measure of the heating requirements of a building expressed in Btu per degree-day.

To disconnect a transmission and/or distribution line; a power line that is not carrying a current; to open a circuit.

In reference to solar energy systems, the angle that a solar collector is positioned above horizontal.

As defined by the Energy Security Act (PL 96-294) of 1980, "any organic matter which is available on a renewable basis, including agricultural crops and agricultural wastes and residues, wood and wood wastes and residues, animal wastes, municipal wastes, ...

Discharging a battery to 20 percent or less of its full charge capacity.

A popular term for "non-conventional" transportation fuels derived from natural gas (propane, compressed natural gas, methanol, etc.) or biomass materials (ethanol, methanol).

Water saturated or strongly impregnated with salt.

A program of the U.S. Department of Energy (DOE) that implements energy legislation and presidential directives. FEMP provides project financing, technical guidance and assistance, coordination and reporting, and new initiatives for the federal government ...

The process or technologies for producing energy by harnessing the temperature differences (thermal gradients) between ocean surface waters and that of ocean depths. Warm surface water is pumped through an evaporator containing a working fluid in a closed ...

The negative pole or electrode of an electrolytic cell, vacuum tube, etc., where electrons enter (current leaves) the system; the opposite of an anode.

Energy systems supply individual, or small-groups, of energy loads.