The use of mechanical devices such as collectors, storage tanks, and pumps to capture heat energy from the sun for use in space heating/cooling and water heating systems. Other applications include the generation of electricity from solar energy.
The the maximum rate at which energy is used, as measured in kilowatts (kW) in 15 or 30 minute intervals.
Annual Fuel Utilization Efficiency (AFUE)
The total heating output of a furnace during its normal annual usage period for heating, divided by the total energy used.