A vehicle with an engine capable of operating on two different types of fuels.

A popular term used for an evaporative cooling device.

Air that is returned to a heating or cooling appliance from a heated or cooled space.

In reference to a wind energy conversion system, the wind speed profile in which wind speeds increase with the logarithmic of the height of the wind turbine above the ground.

The resistance between metallic contacts and the semiconductor.

A circular projection of the sky vault onto a flat diagram used to determine solar positions and shading effects of landscape features on a solar energy system.

A high R-value insulation product usually made from urethane that can be injected into wall cavities, or sprayed onto roofs or floors, where it expands and sets quickly.

The solar power density incident on a surface of stated area and orientation, usually expressed as Watts per square meter or Btu per square foot per hour.

A unit of volume equal to 1 cubic foot at a pressure base of 14.73 pounds standard per square inch absolute and a temperature base of 60 degrees Fahrenheit.

A type of furnace in which fuel is burned and the heat is used to produce steam.

Water in vapor form; used as the working fluid in steam turbines and heating systems.

A heat exchanger in which two fluids flow in opposite directions for transfer heat energy from one to the other.

Categories of energy consumers, as defined by consumption or demand levels, patterns, and conditions, and generally included residential, commercial, industrial, agricultural.

The amount of power density in sunlight received at the earth's surface at noon on a clear day (about 1,000 Watts/square meter).

Solar energy systems that collect or absorb solar energy for useful purposes. Can be used to generate high temperature heat (for electricity production and/or process heat), medium temperature heat (for process and space/water heating and electricity gene ...

The process by which sunlight directly enters a building through the windows and is absorbed and stored in massive floors or walls.

A curve on a chart showing power (kW) supplied (on the horizontal axis) plotted against time of occurrence (on the vertical axis) to illustrate the variance in a load in a specified time period.

Legislation authorizing a U.S. biomass and alcohol fuel program, and that authorized loan guarantees and price guarantees and purchase agreements for alcohol fuel production.

A widely used rate of return for performing economic analysis. This method solves for the interest rate that equates the equivalent worth of an alternative's cash receipts or savings to the equivalent worth of cash expenditures, including investments. The ...

A layer of semiconductor material (as used in a solar photovoltaic device) whose properties are essentially those of the pure, undoped, material.