Energy systems supply individual, or small-groups, of energy loads.

The complex process by which organic matter is decomposed by anaerobic bacteria. The decomposition process produces a gaseous byproduct often called "biogas" primarily composed of methane, carbon dioxide, and hydrogen sulfide.

A pump for circulating the heat transfer fluid in a hydronic heating system.

A component of a hydropower plant; a pipe that delivers water to the turbine.

A slender threadlike spike of pure crystalline material, such as silicon.

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 device that moves and/or circulates air and provides ventilation for a room or a building.

A combustion heating appliance that vents the combustion by-products directly into the heated space. The latest models have oxygen-sensors that shut off the unit when the oxygen level in the room falls below a safe level.

Heat stored above room temperature (in a solar heating system).

A popular term for "non-conventional" transportation fuels derived from natural gas (propane, compressed natural gas, methanol, etc.) or biomass materials (ethanol, methanol).

A program of the U.S. Department of Energy (DOE) that implements energy legislation and presidential directives. FEMP provides project financing, technical guidance and assistance, coordination and reporting, and new initiatives for the federal government ...

A type of combustion heating appliance in which the combustion gases are vented to the outside, either with a fan (forced) or by natural convection.

As defined by the Energy Security Act (PL 96-294) of 1980, "any organic matter which is available on a renewable basis, including agricultural crops and agricultural wastes and residues, wood and wood wastes and residues, animal wastes, municipal wastes, ...

That portion of supply air that is drawn from outside, plus any recirculated air that has been treated to maintain a desired air quality.

A term used for the transparent or translucent material in a window. This material (i.e. glass, plastic films, coated glass) is used for admitting solar energy and light through windows.

The area between the layers of glazing (panes) of a window.

The weight of a material per unit of volume compared to the weight of the same volume of water.

A method of preventing oxidation of the exposed metal in structures by imposing between the structure and the ground a small electrical voltage.

A material used to seal areas of potential air leakage into or out of a building envelope.

The transformation on a compound or material into one or more substances by heat alone (without oxidation). Often called destructive distillation. Pyrolysis of biomass is the thermal degradation of the material in the absence of reacting gases, and occus ...