Energy that comes from splitting atoms of radioactive materials, such as uranium, and which produces radioactive wastes.

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 ...

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

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

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

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.

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

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

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.

A method of depositing thin semiconductor films used to make certain types of solar photovoltaic devices. With this method, a substrate is exposed to one or more vaporized compounds, one or more of which contain desirable constituents. A chemical reaction ...

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

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

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 ...

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

The capability of doing work; different forms of energy can be converted to other forms, but the total amount of energy remains the same.

Defects, such as dangling bonds, induced in an amorphous silicon semiconductor upon initial exposure to light.

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

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 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.

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