The transmission of electricity through power lines.

This designates the resistance of a material to heat conduction. The greater the R-value the larger the number.

In reference to a wind energy conversion system, the area of a turbine blade surface that first comes into contact with the wind.

A type of heating appliance similar to a fireplace, but much more efficient and clean burning. They are made of masonry and have long channels through which combustion gases give up their heat to the heavy mass of the stove, which releases the heat slowly ...

A device used to measure total incident solar radiation (direct beam, diffuse, and reflected radiation) per unit time per unit area.

A gas or liquid used to move heat energy from one place to another; a refrigerant.

One thousand kilowatt-hours or 1 million watt-hours.

A heating system that uses only outside air for combustion and vents combustion gases directly to the outdoors. These systems are less likely to backdraft and to negatively affect indoor air quality.

A measure of the amount of energy lost during the generation, transmission, and distribution of electricity.

A wood-burning appliance for space and/or water heating and/or cooking.

An electricity powered device that extracts available heat from one area (the heat source) and transfers it to another (the heat sink) to either heat or cool an interior space or to extract heat energy from a fluid.

These lights use an electrically heated filament to produce light in a vacuum or inert gas-filled bulb.

The ability to send or wheel electric power to a customer over a transmission and distribution system that is not owned by the generator (seller) of the power.

The change in direction of a ray of light when it passes through one media to another with differing optical densities.

The unit price of a good or service estimated from some base year in order to provide a consistent means of comparison.

A device that produces mechanical energy directly from two heat reservoirs of different temperatures. A machine that converts thermal energy to mechanical energy, such as a steam engine or turbine.

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.

This is a national organization dedicated to representing the interests of cooperative electric utilities and the consumers they serve. Members come from the 46 states that have an electric distribution cooperative.

An aluminum foil fabricated insulator with backings applied to provide a series of closed air spaces with highly reflective surfaces.

A measure of the efficiency of converting a fuel to energy and useful work; useful work and energy output divided by higher heating value of input fuel times 100 (for percent).