The amount of energy absorbed (or converted) by a solar collector (or photovoltaic cell or module) over a 15 minute period.

Pounds/force per square inch gauge.

The process of removing moisture; involves evaporation.

Any liquid petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine. Domestic (residential) heating fuels are classed as Nos. 1, 2, 3; Industrial fuels as Nos. 4, 5, and 6.

Waste water from a household source other than a toilet. This water can be used for landscape irrigation depending upon the source of the greywater.

A column of gas at standard conditions of temperature and pressure (32 degrees Fahrenheit and one atmosphere).

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 ...

A slightly sloped roof, usually with a tar and gravel cover. Most commercial buildings use this kind of roof.

Materials that prevent or slow down the movement of heat.

A building that is elongated in the east-west direction, with the majority of the windows on the south side. The area of the windows is generally limited to about 7% of the total floor area. A sun-tempered design has no added thermal mass beyond what is a ...

The relative extent that energy is required for a process.

A thermodynamic property of a substance, defined as the sum of its internal energy plus the pressure of the substance times its volume, divided by the mechanical equivalent of heat. The total heat content of air; the sum of the enthalpies of dry air and w ...

A group of solar photovoltaic modules connected together.

A toilet that uses less water than a standard one during flushing, for the purpose of conserving water resources.

A law that requires electric utilities to purchase electricity produced from qualifying power producers that use renewable energy resources or are cogenerators. Utilities are required to purchase power at a rate equal to the avoided cost of generating the ...

A popular term used for an evaporative cooling device.

A building heating, ventilation, and/or air conditioning system that distributes conditioned air to individual zones or rooms.

A general term for the visible and near visible (ultraviolet and near-infrared) electromagnetic radiation that is emitted by the sun. It has a spectral, or wavelength, distribution that corresponds to different energy levels; short wavelength radiation ha ...

The lowest wind speed at which a wind turbine begins producing useable power.

A photovoltaic device where incident sunlight is split into different spectral regions, with an optical apparatus, that are directed to individual photovoltaic cells that are optimized for converting that spectrum to electricity.