A type of passive solar heating system where heat is collected in one area for use in another.

A device that can be set to automatically turn appliances (lights) off and on at set times.

To allow or augment the natural movement of cooler air from exterior, shaded areas of a building through or around a building.

This device can automatically turn the heater off at night and on in the morning.

A type of incandescent lamp that contains a halogen gas in the bulb, which reduces the filament evaporation rate increasing the lamp life. The high operating temperature and need for special fixtures limits their use to commercial applications and for use ...

Costs that are repetitive and occur when an organization produces similar goods or services on a continuing basis.

The process of moving existing loads to off-peak periods.

An electrical generator that runs at a constant speed and draws its excitation from a power source external or independent of the load or transmission network it is supplying.

The length of time that a product or appliance is expected to meet a certain level of performance under nominal operating conditions; in a luminaire, the period after which the lumen depreciation and lamp failure is at 70% of its initial value.

This law states that no device can completely and continuously transform all of the energy supplied to it into useful energy.

A wall with high thermal mass used to store solar energy passively in a solar home. The wall absorbs solar energy and transfers it to the space behind the wall by means of radiation and by convection currents moving through spaces under, in front of, and ...

These fluids can be either water or steam trapped in fractured or porous rocks; they are found from several hundred feet to several miles below the Earth's surface. The temperatures vary from about 90 F to 680 F (32 C to 360 C) but roughly 2/3 range in te ...

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 unit of air cooling capacity; 12,000 Btu per hour.

An electric motor rated at less than one horse power (hp).

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

These are state government agencies responsible for the regulation of public utilities within a state or region. A state legislature oversees the PUC by reviewing changes to utility laws, rules and regulations and approving the PUC's budget. The commissio ...

A water heater that uses electricity to move heat from one place to another instead of generating heat directly.

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 ...

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 ...