NREL

Term	Term Definition	Options	Unit of Measure
Energy recovery	The net total energy (sensible plus latent, also called enthalpy) recovered by the supply airstream adjusted by electric consumption, case heat loss or heat gain, air leakage and air flow mass imbalance between the two airstreams, as a percent of the potential total energy that could be recovered plus associated fan energy.	View	None
Fuel cell	A single fuel cell consists of an electrolyte sandwiched between two electrodes. Bipolar plates on either side of the cell help distribute gases and serve as current collectors. Depending on the application, a fuel cell stack may contain a few to hundreds of individual fuel cells layered together. This "scalability" makes fuel cells ideal for a wide variety of applications, such as stationary power stations, portable devices, and transportation.	View	None
Heating Hot Water	A pump used to convey hot water for mechanical heating, typically in the context of a hot water system.	View	None
Linear fresnel reflector	Linear Fresnel reflector systems are a type of linear concentrating systems that collects the sun's energy using long rectangular, curved (U-shaped) mirrors where one receiver tube is positioned above several mirrors to allow the mirrors greater mobility in tracking the sun. The mirrors are tilted toward the sun, focusing sunlight on tubes (or receivers) that run the length of the mirrors. The reflected sunlight heats a fluid flowing through the tubes. The hot fluid then is used to boil water in a conventional steam-turbine generator to produce electricity.	View	None
NREL Wind CLASS	Wind power density (WPD) is a calculation of the mean annual power available per square meter of swept area of a turbine. Classes are defined by NREL. Class specifics can be found at http://www.nrel.gov/gis/wind_detail.html	View	None
Solar dish	A solar dish/engine system uses a mirrored dish similar to a very large satellite dish, although to minimize costs, the mirrored dish is usually composed of many smaller flat mirrors formed into a dish shape. The dish-shaped surface directs and concentrates sunlight onto a thermal receiver, which absorbs and collects the heat and transfers it to the engine generator. The most common type of heat engine used today in dish/engine systems is the Stirling engine. This system uses the fluid heated by the receiver to move pistons and create mechanical power. The mechanical power is then used to run a generator or alternator to produce electricity.	View	None
Solar parabolic trough	Solar parabolic troughs are a type of linear concentrator system that collects the sun's energy using long rectangular, curved (U-shaped) mirrors where receiver tubes are positioned along the focal line of each parabolic mirror. The mirrors are tilted toward the sun, focusing sunlight on tubes (or receivers) that run the length of the mirrors. The reflected sunlight heats a fluid flowing through the tubes. The hot fluid then is used to boil water in a conventional steam-turbine generator to produce electricity.	View	None
Solar power tower	A power tower system uses a large field of flat, sun-tracking mirrors known as heliostats to focus and concentrate sunlight onto a receiver on the top of a tower. A heat-transfer fluid heated in the receiver is used to generate steam, which, in turn, is used in a conventional turbine generator to produce electricity. Some power towers use water/steam as the heat-transfer fluid. Other advanced designs are experimenting with molten nitrate salt because of its superior heat-transfer and energy-storage capabilities. The energy-storage capability, or thermal storage, allows the system to continue to dispatch electricity during cloudy weather or at night.	View	None
Weather Data Station ID	For an actual weather station, this is the ID assigned by NOAA. For hourly energy simulations, this is the six digit code associated with the hourly weather data, generally found in the name of the weather data file, as well as in the header of the data file.	View	None
Weather Data Type	For hourly energy simulations, the type of data used in the hourly weather data. This information is generally found in the name of the weather data file, as well as in the header of the data file. In the United States, the normal type of data is Typical Meteorological Year (TMY), which represent a year of typical climatic conditions for a location. The data set is composed of 12 months of typical meteorological data concatenated to form a single year with a complete data set for primary measurements. The monthly data sets contain actual meteorological measurements and modeled solar values.	View	None
Weather Station Category	Describes the type of weather station used to specify the site's weather.	View	None
Weather Station Name	The name of the weather station associated with this premises, which could be used for simulations, weather normalization, anomaly resolution, etc. For simulations, this is usually the name of the weather file, but the name is also in the header of the data file (TMY, IWEC), such as USA_CO_Denver.Intl.AP.	View	None