One quadrillion Btu. (1,000,000,000,000,000 Btu)

The positive pole or electrode of an electrolytic cell, vacuum tube, etc. (see also sacrificial anode).

A wall that carries ceiling rafters or roof trusses.

A measure of the flow of current (in amperes) over one hour.

A wall usually about 3 to 4 feet high located that is placed in the attic of a home, anchored with plates between the attic floor joists and the roof joist. Sheathing can be attached to these walls to enclose an attic space.

A type of heat pump that transfers heat in outdoor air to water for space or water heating.

The ratio of the average load on (or power output of) a generating unit or system to the capacity rating of the unit or system over a specified period of time.

The process of decomposing biomass with anaerobic bacteria to produce biogas.

The presence of contaminants in the air in concentrations that prevent the normal dispersive ability of the air, and that interfere with biological processes and human economics.

A chemical change in a substance that results from the passage of an electric current through an electrolyte. The production of commercial hydrogen by separating the elements of water, hydrogen, and oxygen, by charging the water with an electrical current ...

Biomass converted directly to energy or converted to liquid or gaseous fuels such as ethanol, methanol, methane, and hydrogen.

A unit of measure for an electrical current; the amount of current that flows in a circuit at an electromotive force of one Volt and at a resistance of one Ohm. Abbreviated as amp.

A fan mounted on an attic wall used to exhaust warm attic air to the outside.

The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.

An interior court to which rooms open.

The product of 1 hour, and usually the number of degrees Fahrenheit the hourly mean temperature is above a base point (usually 65 degrees Fahrenheit); used in roughly estimating or measuring the cooling load in cases where processes heat, heat from buildi ...

A movable plate used to control air flow; in a wood stove or fireplace, used to control the amount and direction of air going to the fire.

Microorganisms that live in oxygen deprived environments.

Describes the reliability of power plants. It refers to the number of hours that a power plant is available to produce power divided by the total hours in a set time period, usually a year.

A hard, dense type of coal, that is hard to break, clean to handle, difficult to ignite, and that burns with an intense flame and with the virtual absence of smoke because it contains a high percentage of fixed carbon and a low percentage of volatile matt ...