The tank of a water heater.

A curve that displays load values on the horizontal axis in descending order of magnitude against the percent of time (on the vertical axis) that the load values are exceeded.

A power plant that produces electricity by the force of water falling through a hydro turbine that spins a generator.

Fabricated as a single structure.

A passage for surplus water to flow over or around a dam.

Electromagnetic radiation whose wavelengths lie in the range from 0.75 micrometer to 1000 micrometers; invisible long wavelength radiation (heat) capable of producing a thermal or photovoltaic effect, though less effective than visible light.

The solar power density incident on a surface of stated area and orientation, usually expressed as Watts per square meter or Btu per square foot per hour.

A building element that provides protection against the sun, wind, and precipitation.

The angle that a solar collector is positioned from horizontal.

The power required to energize the magnetic field of a generator.

A machine supplied with external energy that is converted into force and/or motion.

A type of solar photovoltaic device made in a continuous process of pulling material from a molten bath of photovoltaic material, such as silicon, to form a thin sheet of material.

A term used to describe a technologically advanced window system that contains glazing that can change or switch its optical qualities when a low voltage electrical signal is applied to it, or in response to changes in heat or light.

An energy band in a semiconductor in which electrons can move freely in a solid, producing a net transport of charge.

see Peak Watt.

Legal documents that regulate construction to protect the health, safety, and welfare of people. Codes establish minimum standards but do not guarantee efficiency or quality.

A means of billing electric power consumers to pay for the costs of demand side management/energy conservation measures and programs. (See also Benefits Charge.)

A chemical element that can be used as a fuel since it has a very high energy content.

A stationary or rotating vent used to ventilate attics or cathedral ceilings; usually made of galvanized steel, or polypropylene.

An arrangement of photovoltaic cells or material mounted on a rigid flat surface with the cells exposed freely to incoming sunlight.