The direction, at any point on the earth that is geographically in the northern hemisphere, facing toward the South Pole of the earth. Essentially a line extending from the point on the horizon to the highest point that the sun reaches on any day (solar n ...

A mechanism used by electric utilities to determine prices for electricity; typically defines rates according to amounts of power demanded/consumed during specific time periods.

A safety device consisting of a short length of relatively fine wire, mounted in a holder or contained in a cartridge and connected as part of an electrical circuit. If the circuit source current exceeds a predetermined value, the fuse wire melts (i.e. th ...

The inherent characteristic of a material to inhibit the transfer of energy. In electrical conductors, electrical resistance results in the generation of heat. Electrical resistance is measured in Ohms. The heat transfer resistance properties of insulatio ...

An electromagnetic device that changes the voltage of alternating current electricity. It consists of an induction coil having a primary and secondary winding and a closed iron core.

A device for converting the flow of a fluid (air, steam, water, or hot gases) into mechanical motion.

Parasitic resistance to current flow in a cell due to mechanisms such as resistance from the bulk of the semiconductor material, metallic contacts, and interconnections.

The shape of the phase power at a certain frequency and amplitude.

The pressure equivalent of the velocity of a fluid.

A device used to remove particulate matter from the waste gasses of a combustion power plant.

A company that specializes in undertaking energy efficiency measures under a contractual arrangement whereby the ESCo shares the value of energy savings with their customer.

A clear, colorless, very mobile liquid that is flammable and poisonous; used as a fuel and fuel additive, and to produce chemicals.

A window glass that has been coated with a reflective film and is useful in controlling solar heat gain during the summer.

A heat engine of the reciprocating (piston) where the working gas and a heat source are independent. The working gas is compressed in one region of the engine and transferred to another region where it is expanded. The expanded gas is then returned to the ...

For a wind turbine, the ratio of the speed of the tip of a turbine blade for which the power coefficient is at maximum.

A chemical compound produced in a reaction between ethanol and isobutylene (a petroleum-derived by-product of the refining process). ETBE has characteristics superior to other ethers: low volatility, low water solubility, high octane value, and a large re ...

A tank used in a closed-loop solar heating system that provides space for the expansion of the heat transfer fluid in the pressurized collector loop.

One horsepower provided over one hour; equal to 0.745 kilowatt-hour or 2,545 Btu.

Electrical energy lost due to inherent inefficiencies in an electrical transmission and distribution system under specific conditions.

The fundamental constituent of all vegetative tissue; the most abundant material in the world.