A pole used to assist in raising a tower.

An index that combines sensible temperature and air humidity to arrive at a number that closely responds to the effective temperature; used to relate temperature and humidity to levels of comfort.

The value of a personal portfolio, product, or investment after depreciation and interest on debt capital are subtracted from operating income. It can also be thought of as the equivalent worth of all cash flows relative to a base point called the present ...

An electric current induced by radiant energy.

A construction material made by compressing earth in a form; used traditionally in many areas of the world and widely throughout North Africa and the Middle East.

A sinusoidal quantity having a frequency that is an integral multiple of the frequency of a periodic quantity to which it is related.

The change in the power available in the wind due to changes in the windspeed or velocity profile; the windpower profile is proportional to the cube of the wind speed profile.

The complete cycle of stages (evaporation and condensation) of refrigeration or of the refrigerant.

The replacement of a non-functional or ineffective lamp with a new, more efficient lamp.

A device that transfers heat by the continuous evaporation and condensation of an internal fluid.

The ratio of fuel energy input as heat per unit of net work output; a measure of a power plant thermal efficiency, generally expressed as Btu per net kilowatt-hour.

The pressure equivalent of the velocity of a fluid.

Thermosyphon systems use a separate storage tank located above the collector. Liquid warmed in the collector rises naturally above the collector, where it is kept until it is needed. The liquid can be either water or a glycol solution. If the fluid is wat ...

A solar energy conversion device that has a bowl shaped dish covered with a highly reflective surface that tracks the sun and concentrates sunlight on a fixed absorber, thereby achieving high temperatures, for process heating or to operate a heat (Stirlin ...

A wheel that is designed to use the weight and/or force of moving water to turn it, primarily to operate machinery or grind grain.

A solar water or space-heating system in which solar energy is collected, and/or moved by natural convection without using pumps or fans. Passive systems are typically integral collector/storage (ICS; or batch collectors) or thermosyphon systems. The majo ...

The rate of energy transfer equivalent to one ampere under an electrical pressure of one volt. One watt equals 1/746 horsepower, or one joule per second. It is the product of Voltage and Current (amperage).

A component of a water heating system that opens at a designated temperature or pressure to prevent a possible tank, radiator, or delivery pipe rupture.

The rate of flow of the wind undisturbed by obstacles.

A device that uses electronic components to regulate the voltage of fluorescent lamps.