A system of astronomical time in which the sun crosses the true north-south meridian at 12 noon, and which differs from local time according to longitude, time zone, and equation of time.

A group of solar photovoltaic modules connected together.

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 process used to apply photovoltaic semi-conductor material to a substrate by a physical vapor deposition process where high-energy ions are used to bombard elemental sources of semiconductor material, which eject vapors of atoms that are then deposited ...

One pound of water in vapor phase; is NOT steam pressure, which is expressed as pounds per square inch (psi).

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

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

A particle of light that acts as an individual unit of energy.

The fluid, liquid (water or water/antifreeze solution) or air, used to absorb solar energy and transfer it for direct use, indirect heating of interior air or domestic water, and/or to a heat storage medium.

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.

A load management objective that moves loads from on-peak periods to off-peak periods.

The component of a solar energy heating system that collects solar radiation, and that contains components to absorb solar radiation and transfer the heat to a heat transfer fluid (air or liquid).

A popular term used for an evaporative cooling device.

The direct, diffuse, and reflected solar radiation that strikes a surface.

A utility owned by stockholders or other investors; sometimes referred to as a private utility, in contrast to a public utility that is owned by a government agency or cooperative.

To influence the demand on a power source.

The number of cycles through which an alternating current passes per second; in the U.S. the standard for electricity generation is 60 cycles per second (60 Hertz).

The unoccupied, and usually unfinished and unconditioned space between the floor, foundation walls, and the slab or ground of a building.

The temperature of the air as measured by a standard thermometer.

Ethyl alcohol (C2H5OH)