APES Chapter 16

PV cell

Device that converts radiant (solar) energy directly into electrical energy.

photovoltaic cell (solar cell)

Device that converts radiant (solar) energy directly into electrical energy.

solar cell (photovoltaic cell)

Device that converts radiant (solar) energy directly into electrical energy.

geothermal energy

Heat transferred from the earth's underground concentrations of dry steam (steam with no water droplets), wet steam (a mixture of steam and water droplets), or hot water trapped in fractured or porous rock.

energy efficiency

Percentage of the total energy input that does useful work and is not converted into low-quality, usually useless heat in an energy conversion system or process. See energy quality, net energy.

cogeneration (CHP)

Production of two useful forms of energy, such as high-temperature heat or steam and electricity, from the same fuel source.

passive solar heating system

System that captures sunlight directly within a structure and converts it into low-temperature heat for space heating or for heating water for domestic use without the use of mechanical devices.

active solar heating system

System that uses solar collectors to capture energy from the sun and store it as heat for space heating and water heating. Liquid or air pumped through the collectors transfers the captured heat to a storage system such as an insulated water tank or rock bed. Pumps or fans then distribute the stored heat or hot water throughout a dwelling as needed.