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

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

The temperature at which a material ignites.

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

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

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.

Two metals of different coefficients of expansion welded together so that the piece will bend in one direction when heated, and in the other when cooled, and can be used to open or close electrical circuits, as in thermostats.

A thermodynamic cycle using constant pressure, heat addition and rejection, representing the idealized behavior of the working fluid in a gas turbine type heat engine.

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.

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

A combustible gas created by anaerobic decomposition of organic material, composed primarily of methane, carbon dioxide, and hydrogen sulfide.

The number of degrees per day that the daily average temperature (the mean of the maximum and minimum recorded temperatures) is below a base temperature, usually 65 degrees Fahrenheit, unless otherwise specified; used to determine indoor space heating req ...

The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.

A component of a heating or ventilation appliance used to conduct fresh air into, or waste air or combustion gases out of, an appliance or interior space.

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 amount of heat required to raise the temperature of one pound of water one degree Fahrenheit; equal to 252 calories.

A fluid, such as methanol or ethylene glycol, added to vehicle engine coolant, or used in solar heating system heat transfer fluids, to protect the systems from freezing.

A wall that carries ceiling rafters or roof trusses.

The temperature of a medium, such as gas or liquid, which comes into contact with or surrounds an apparatus or building element.

A type of electric generator that produces alternating current that matches an existing power source.