A type of anaerobic digester that has a mechanical mixing system and where temperature and volume are controlled to maximize the anaerobic digestion process for biological waste treatment, methane production, and odor control.

The quantity of heat required to change the temperature of one unit weight of a material by one degree.

A term used to describe short and long-term affects on the Earth's climate as a result of human activities such as fossil fuel combustion and vegetation clearing and burning.

A valve operated by a thermostat that can be installed in solar water heating systems to mix cold water with water from the collector loop to maintain a safe water temperature.

A solid-state electrical device that converts light directly into direct current electricity of voltage-current characteristics that are a function of the characteristics of the light source and the materials in and design of the device. Solar photovoltai ...

The outer casing of a window that sits in a designated opening of a structure and holds the window panes in place.

Fuels formed in the ground from the remains of dead plants and animals. It takes millions of years to form fossil fuels. Oil, natural gas, and coal are fossil fuels.

The measure of closeness in shape between a waveform and it's fundamental component.

An electrically charged atom or group of atoms that has lost or gained electrons; a loss makes the resulting particle positively charged; a gain makes the particle negatively charged.

A system where heat is supplied to areas of a building from a single appliance through a network of ducts or pipes.

A thermostat that can be set to automatically lower temperatures in an unoccupied house and raise them again before the occupant returns.

An open-loop solar heating system in which the heat transfer fluid from the collector loop and the piping drain into a drain whenever freezing conditions occur.

A small groove scribed into the surface of a solar photovoltaic cell which is filled with metal for contacts.

All the natural and living things around us. The earth, air, weather, plants, and animals all make up our environment.

Any material that can be burned to make energy.

A smaller version of standard fluorescent lamps which can directly replace standard incandescent lights. These lights consist of a gas filled tube, and a magnetic or electronic ballast.

Water heated for residential washing, bathing, etc.

Electric power plant or utility capacity on line and running at low power in excess of actual load.

The temperature that a system is designed to maintain (inside) or operate against (outside) under the most extreme conditions.

Materials that prevent or slow down the movement of heat.