A type of anaerobic digester that has a horizontal tank in which a constant volume of material is added and forces material in the tank to move through the tank and be digested.

The amount of solar energy that passes through a glazing material, expressed as a percentage.

The quantity of heat that a cooling appliance is capable of removing from a room in one hour.

A method of financial and economic analysis used to determine present and future values of investments or expenses.

The period marked by successive crossing of the earth's meridian by the sun; the hour angle of the sun at a point of observance (apparent time) is corrected to true (solar) time by taking into account the variation in the earth's orbit and rate of rotatio ...

Usually refers to ethanol to 160 to 200 proof.

The two times of the year when the sun is apparently farthest north and south of the earth's equator; usually occurring on or around June 21 (summer solstice in northern hemisphere, winter solstice for southern hemisphere) and December 21 (winter solstice ...

A deposition process whereby heat is used to break molecules into elemental sources that are then spray deposited on a substrate.

The total distribution of electromagnetic radiation emanating from the sun. The different regions of the solar spectrum are described by their wavelength range. The visible region extends from about 390 to 780 nanometers (a nanometer is one billionth of o ...

A solid that contains pores; normally, it refers to interconnected pores that can transmit the flow of fluids. (The term refers to the aquifer geology when discussing sites for CAES.)

The air that is supplied to the combustion chamber of a furnace.

A steady-state fermentation process.

The time of the day, at a specific location, when the sun reaches its highest, apparent point in the sky; equal to true or due, geographic south.

A water and energy conserving device that limits the amount of water that a faucet or showerhead can deliver.

Strips of material used to separate multiple panes of glass within the windows.

A window located on the roof of a structure to provide interior building spaces with natural daylight, warmth, and ventilation.

A type of high intensity discharge light that has the most lumens per watt of any light source.

A measure of light quality. The maximum CRI value of 100 is given to natural daylight and incandescent lighting. The closer a lamp's CRI rating is to 100, the better its ability to show true colors to the human eye.

Those gases, such as water vapor, carbon dioxide, tropospheric ozone, methane, and low level ozone that are transparent to solar radiation, but opaque to long wave radiation, and which contribute to the greenhouse effect.

A plot of a wind energy conversion device's power output versus wind speed.