The amount of electromotive force, measured in volts, that exists between two points.

A device, such as a steel plate, used to check, retard, or divert a flow of a material.

A type of ceiling and roof assembly that has no attic.

One quadrillion Btu. (1,000,000,000,000,000 Btu)

A wall usually about 3 to 4 feet high located that is placed in the attic of a home, anchored with plates between the attic floor joists and the roof joist. Sheathing can be attached to these walls to enclose an attic space.

This is the voltage-ampere requirement of a device designed to convert electric energy to a non-electrical form.

A building construction technique used to create a continuous air retarder that uses the drywall, gaskets, and caulking. Gaskets are used rather than caulking to seal the drywall at the top and bottom. Although it is an effective energy-saving technique, ...

The measure of seasonal or annual efficiency of a residential heating furnace or boiler. It takes into account the cyclic on/off operation and associated energy losses of the heating unit as it responds to changes in the load, which in turn is affected by ...

The cost of producing electricity up to the point of the powerplant busbar.

A component of a electrochemical battery. A 'primary' cell consists of two dissimilar elements, known as 'electrodes,' immersed in a liquid or paste known as the 'electrolyte.' A direct current of 1-1.5 volts will be produced by this cell. A 'secondary' c ...

A thin coating of a material applied to a photovoltaic cell surface that reduces the light reflection and increases light transmission.

A chemical change in a substance that results from the passage of an electric current through an electrolyte. The production of commercial hydrogen by separating the elements of water, hydrogen, and oxygen, by charging the water with an electrical current ...

Energy required to operate mechanical components of an energy system, or a source of energy or energy supply system to back-up another.

The demand on, or the power output of, an electrical system or any of its parts over an interval of time, as determined by the total number of kilowatt-hours divided by the units of time in the interval.

The temperature at which a material ignites.

The usually unfinished space above a ceiling and below a roof.

A measure of the flow of current (in amperes) over one hour.

The chemical element commonly used as the dopant in solar photovoltaic device or cell material.

The ratings under which specified appliances convert energy sources into useful energy, as determined by procedures established by the U.S. Department of Energy.

The refrigerating effect in Btu/h produced by the difference in total enthalpy between a refrigerant liquid leaving the unit and the total enthalpy of the refrigerant vapor entering it. Generally measured in tons or Btu/h.