Energy terms starting with H

142 terms

101. Horizon line The apparent line in the landscape formed by the meeting of the visible land surface and the sky.
102. Horizontal angle of view The angle of landscape viewed in sharp focus, measured along the horizon, without turning the head. See also Vertical angle of view; Angle of view
103. Horizontal field of view See Horizontal angle of view
104. Horizontal Ground Loop In this type of closed-loop geothermal heat pump installation, the fluid-filled plastic heat exchanger pipes are laid out in a plane parallel to the…
105. Horizontal-Axis Wind Turbines Turbines in which the axis of the rotor's rotation is parallel to the wind stream and the ground.
106. Horsepower (hp) A unit of rate of operation. Electrical hp: a measure of time rate of mechanical energy output; usually applied to electric motors as the maximum output…
107. Horsepower Hour (hph) One horsepower provided over one hour; equal to 0.745 kilowatt-hour or 2,545 Btu.
108. Horst An elongated crustal block that is relatively raised between two parallel normal faults or grabens. See also Half-graben
109. Hot Air Furnace A heating unit where heat is distributed by means of convection or fans.
110. Hot Dry Rock A geothermal energy resource that consists of high temperature rocks above 300 F (150 C) that may be fractured and have little or no water.
111. Hot Water Heating Systems (See Hydronic)
112. Housing Element A comprehensive assessment of current and projected housing needs for all economic segments of the community.
113. Hub A network device that connects multiple computers/peripherals together and allows them to share data.
114. Hub Height The height above the ground that a horizontal axis wind turbine's hub is located.
115. Humidifier (hyoo-MID-ih-fye-er) A machine that puts moisture in the air.
116. Humidity A measure of the moisture content of air; may be expressed as absolute, mixing ratio, saturation deficit, relative, or specific.
117. Hunter gatherers A term applied to people whose diet is based on hunting, fishing, and gathering, as opposed to domesticating animals or plants.
118. Hunting Includes big- and small-game hunting, waterfowl hunting, and trapping.
119. HVAC Heating, Ventilation and Air Conditioning; a home's heating and cooling system.
120. Hybrid A class that is a mixture or combination of 2 or more classes. For example, a Druid can be viewed as a Warrior/Rogue/Priest hybrid.
121. Hybrid (wet-dry cooling) systems A variation on a dry cooling system. In this hybrid system, small amounts of water are sprayed as a fine mist into the flow of ambient air being directed…
122. Hybrid electric vehicle A vehicle that is powered by two or more energy sources, one of which is electricity.
123. hybrid system A renewable energy system that includes two different types of technologies that produce the same type of energy; for e.g.
124. Hydraulic gradient In an aquifer, the rate of change of total head per unit of distance of flow at a given point and in a given direction.
125. Hydraulic load Amount of liquid going into a system.
126. Hydro-compactable, collapsible soil (settlement) Low-density soils that undergo appreciable loss of volume when wetted or subjected to increased load (or both).
127. Hydrocarbon Any chemical compound containing hydrogen, oxygen, and carbon.
128. hydrocracking A process in which hydrogen is added to organic molecules at high pressures and moderate temperatures; usually used as an adjunct to catalytic cracking.
129. Hydroelectric power The generation of electricity using falling water.
130. Hydroelectric Power Plant A power plant that produces electricity by the force of water falling through a hydro turbine that spins a generator.
131. Hydrofluorocarbon (HFC) Man-made chemicals, many of which have been developed as alternatives to ozone-depleting substances (ODSs) for industrial, commercial, and consumer…
132. Hydrogen A chemical element that can be used as a fuel since it has a very high energy content.
133. Hydrogenated Amorphous Silicon Amorphous silicon with a small amount of incorporated hydrogen. The hydrogen neutralizes dangling bonds in the amorphous silicon, allowing charge carriers…
134. hydrogenation Treatment of substances with hydrogen and suitable catalysts at high temperature and pressure to saturate double bonds.
135. Hydrology The science dealing with the distribution, properties and circulation of water on land, in the soil, and in the atmosphere.
136. Hydrolysis A chemical reaction that uses water to break down a compound.
137. Hydronic Heating Systems A type of heating system where water is heated in a boiler and either moves by natural convection or is pumped to heat exchangers or radiators in rooms…
138. Hydropower The force of flowing water moving downstream creates energy that can be harnessed and turned into electricity.
139. Hydrostratigraphic Grouping of rock and sedimentary units based on the capacity of the rock, sediment, or soil to transmit water.
140. Hydrothermal fluids These fluids can be either water or steam trapped in fractured or porous rocks; they are found from several hundred feet to several miles below the…
141. Hypothesis A tentative proposal made to explain certain observations or facts that requires further investigation to be verified.
142. Hz See Hertz