Caulking and weatherstripping to reduce air infiltration and exfiltration into/out of a building.

A ratio of the work or useful energy output of a system versus the amount of work or energy inputted into the system as determined by using the same energy equivalents for energy in and out. Is used as a measure of the steady state performance or energy e ...

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

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

As time increases from zero at the terminals of an inductor, the voltage comes to a particular value on the sine function curve ahead of the current. The voltage reaches its negative peak exactly 90 degrees before the current reaches its negative peak thu ...

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 supportive structure of a building.

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

An architectural design invented by Buckminster Fuller with a regular polygonal structure based on radial symmetry.

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

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 ...

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

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.

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

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 ...

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

The power available from the rise and fall of ocean tides. A tidal power plant works on the principal of a dam or barrage that captures water in a basin at the peak of a tidal flow, then directs the water through a hydroelectric turbine as the tide ebbs.

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 device for measuring light intensity that works by converting light falling on, or reach it, to electricity, and then measuring the current; used in photometers.

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