The angle at which a solar collector or module is set to face the sun relative to a horizontal position. The tilt angle can be set or adjusted to maximize seasonal or annual energy collection.

A hydrogen production process that process uses algae. Under certain conditions, the pigments in certain types of algae absorb solar energy. An enzyme in the cell acts as a catalyst to split water molecules. Some of the bacteria produces hydrogen after th ...

A horizontal axis wind turbine in which the rotor is downwind of the tower.

A characteristic applied to domestic water heaters that is the amount of gallons raised 100 degrees Fahrenheit per hour (or minute) under a specified thermal efficiency.

A solar thermal system that has one tank for storing solar heated water to preheat the water in a conventional water heater.

A device used to remove particulate matter from the waste gasses of a combustion power plant.

Energy conversion technologies that harness the energy in tides, waves, and thermal gradients in the oceans.

As a component of a heating or cooling appliance, rows of tubing or pipe with fins attached through which a heat transfer fluid is circulated and to deliver heat or cooling energy to a building.

This law states that no device can completely and continuously transform all of the energy supplied to it into useful energy.

A window glass that has been coated with a reflective film and is useful in controlling solar heat gain during the summer.

The process of converting materials that are no longer useful as designed or intended into a new product.

Air that is returned from a heated or cooled space, reconditioned and/or cleaned, and returned to the space.

Caulking and weatherstripping to reduce air infiltration and exfiltration into/out of a building.

To allow or augment the natural movement of cooler air from exterior, shaded areas of a building through or around a building.

An electrical generator that runs at a constant speed and draws its excitation from a power source external or independent of the load or transmission network it is supplying.

A mechanism used by electric utilities to determine prices for electricity; typically defines rates according to amounts of power demanded/consumed during specific time periods.

This device can automatically turn the heater off at night and on in the morning.

A device for measuring light intensity that works by converting light falling on, or reach it, to electricity, and then measuring the current; used in photometers.

The component of a central receiver solar thermal system where reflected solar energy is absorbed and converted to thermal energy.

Energy that comes from splitting atoms of radioactive materials, such as uranium, and which produces radioactive wastes.