Energy terms starting with I

105 terms

I-Type Semiconductor A semiconductor material that is left intrinsic, or undoped so that the concentration of charge carriers is characteristic of the material itself rather…
I-V Curve A graphical plot or representation the current and voltage output of a solar photovoltaic cell or module as a load on the device is increased from short…
Igneous rock A crystalline rock formed by the cooling and solidification of molten or partly molten material (magma).
Ignite To heat a gaseous mixture to the temperature at which combustion takes place.
Ignition Point The minimum temperature at which combustion of a solid or fluid can occur.
Illuminance A measure of the amount of light incident on a surface; measured in foot-candles or Lux.
Illumination The distribution of light on a horizontal surface. The purpose of all lighting is to produce illumination.
Imbalance energy Discrepancy between the amount that a seller contracted to deliver and the actual volume of power delivered.
Imhoff treatment system In wastewater treatment, a tank without aeration or oxygenation where solids settle out. The solids are digested in a separate compartment in the bottom.
Impact The effect, influence, alteration, or imprint caused by an action.
Impact Fees Costs imposed on new development to fund public facility improvements required by new development and ease fiscal burdens on localities.
Impermeable Refers to a rock matrix that water cannot infiltrate.
Impervious Surface Any surface through which rainfall cannot pass or be effectively absorbed. (Roads, buildings, paved parking lots, sidewalks etc.)
Imperviousness Overlay Zoning One form of the overlay zoning process. Environmental aspects of future imperviousness are estimated based on the future zoning build-out conditions.
Impingement The entrapment of aquatic organisms on the outer part of an intake structure or against a screening device during periods of intake water withdrawal.
IMPLAN Input-output economic model based on economic accounts showing the flow of commodities to industries from producers and institutional consumers.
Impoundment A body of water confined by a dam, dike, floodgate or other artificial barrier.
Impoundment (surface) A body of water or sludge confined by a dam, dike, floodgate, or other barrier.
Impulse Turbine A turbine that is driven by high velocity jets of water or steam from a nozzle directed to vanes or buckets attached to a wheel.
Impulsive noise Noise from impacts or explosions (e.g., from a pile driver, forging hammer, punch press, or gunshot), which is brief and abrupt, and its startling effects…
In attainment In compliance with air-quality standards. Areas that are in attainment have air quality that is as good as or better than specified in the National…
In situ (in si'too) the natural or normal place; confined to the site of origin without invasion or spread to neighboring tissues.
In-migration People moving into an area.
Incandescent These lights use an electrically heated filament to produce light in a vacuum or inert gas-filled bulb.
Incentive Zoning Provides for give and take compromise on zoning restrictions, allowing for more flexibility to provide environmental protection.
Incident Solar Radiation The amount of solar radiation striking a surface per unit of time and area.
Incidental take permit A permit issued under Section 10 of the Federal Endangered Species Act to private parties undertaking otherwise lawful projects that might result in the…
Incinerator Any device used to burn solid or liquid residues or wastes as a method of disposal.
Inclined grate A type of furnace in which fuel enters at the top part of a grate in a continuous ribbon, passes over the upper drying section where moisture is removed…
Inclusionary zoning A system that requires a minimum percentage of lower and moderate income housing to be provided in new developments.
Incremental energy costs The cost of producing and transporting the next available unit of electrical energy.
Incremental Price The additional price of an alternative fuel vehicle over a similar conventional vehicle.
Independent Power Producer A company or individual that is not directly regulated as a power provider. These entities produce power for their own use and/or sell it to regulated…
Independent System Operator (ISO) An independent, Federally regulated entity established to coordinate regional transmission in a non-discriminatory manner and ensure the safety and…
Index Statistical measure of the state of the stock market or economy based on the performance of stocks or other components.
Indian trust assets Lands, natural resources, or other assets held in trust or restricted against alienation by the United States for Native American tribes or individual…
Indian trust resources Those natural resources, either on or off Indian lands, retained by or reserved by or for Indian tribes through treaties, statutes, judicial decisions…
Indirect effects Secondary effects that occur in locations other than that of the initial action or significantly later in time.
Indirect impacts Impacts that occur away from the place of origin. Effects that are related to, but removed from, a proposed action by an intermediate step or process.
Indirect liquefaction Conversion of biomass to a liquid fuel through a synthesis gas intermediate step.
Indirect Solar Gain System A passive solar heating system in which the sun warms a heat storage element, and the heat is distributed to the interior space by convection, conduction…
Indirect Solar Water Heater These systems circulate fluids other than water (such as diluted antifreeze) through the collector.
Induction The act or process of causing some specific effect to occur; for example the transcription of a specific gene or operon, or the production of a protein by…
Induction Generator A device that converts the mechanical energy of rotation into electricity based on electromagnetic induction.
Induction Motor A motor in which a three phase (or any multiphase) alternating current (i.e. the working current) is supplied to iron-cored coils (or windings) within the…
Induration The hardening of a rock, usually sedimentary, by drying, pressure, or cementation.
Industrial Process Heat The thermal energy used in an industrial process.
Industrial waste Materials discarded from industrial operations or derived from manufacturing processes.
Inert Gas A gas that does not react with other substances; e.g. argon or krypton; sealed between two sheets of glazing to decrease the U-value (increase the…
Infill Development Infill projects use vacant or underutilized land in previously developed areas for buildings, parking, and other uses.
Infiltration Leakage of ground water into a sewage collection system.
Infiltration pond A shallow impoundment designed to infiltrate stormwater into the soil. Also referred to as an infiltration basin.
Inflow Water (and pollutants) that enter sewage systems through street inlets, roof drains, and similar sources.
Influent Wastewater going into the sewage treatment plant.
Infrared Radiation Electromagnetic radiation whose wavelengths lie in the range from 0.75 micrometer to 1000 micrometers; invisible long wavelength radiation (heat) capable…
infrastructure An basic underlying framework or features of a system.
Injection season The period from April 1 through October 31, during which gas is injected into natural gas storage reservoirs in preparation for withdrawal and use during…
inoculum (pl.: inocula) 1. A small piece of tissue cut from callus, or an explant from a tissue or organ, or a small amount of cell material from a suspension…
Inorganic compounds Those compounds lacking carbon but including carbonates and cyanides. Compounds not having the organized anatomical structure of animal or vegetable life.
Inset fans An alluvial fan that occurs on top of an older alluvial fan.
Insolation The solar power density incident on a surface of stated area and orientation, usually expressed as Watts per square meter or Btu per square foot per hour.
Installed capacity The total capacity of electrical generation devices in a power station or system.
Instantaneous Efficiency (of a Solar Collector) The amount of energy absorbed (or converted) by a solar collector (or photovoltaic cell or module) over a 15 minute period.
Insulation Materials that prevent or slow down the movement of heat.
Insulation Blanket A pre-cut layer of insulation applied around a water heater storage tank to reduce stand-by heat loss from the tank.
Insulator A device or material with a high resistance to electricity flow.
Intaglio An impression, design, or figure created on the ground by man through the placement of rocks or mounding of earth.
Integral Collector Storage System This simple passive solar hot water system consists of one or more storage tanks placed in an insulated box that has a glazed side facing the sun.
Integrated Heating Systems A type of heating appliance that performs more than one function, for example space and water heating.
Integrated Resource Plan (IRP) A plan developed by an electric power provider, sometimes as required by a public regulatory commission or agency, that defines the short and long term…
Integrated resource planning See least cost planning.
Intensive management Planned, active treatment to improve the quality and quantity of timber within a stand.
Interbasin flow Surface water or groundwater flow between two hydrologic basins.
Interbasin transfer of water A transfer of water rights and/or a diversion of water (either groundwater or surface water) from one drainage or hydrographic basin to another.
Interbasin transfers The transfer of water to another water management basin.
Interconnection A connection or link between power systems that enables them to draw on each other's reserve capacity in time of need.
IntercontinentalExchange (ICE) An exempt exchange under CFMA 2000. It is exempt from many reporting requirements that are required of Nymex.
Interdune flat The area between dunes, generally flat and often erosion-resistant.
Intermittent Generators Power plants, whose output depends on a factor(s) that cannot be controlled by the power generator because they utilize intermittent resources such as…
Intermittent Stream A stream that flows for a portion of the year but occasionally is dry or reduced to a pool stage when losses from evaporation or seepage exceed the…
Intermodal Those issues or activities which involve or affect more than one mode of transportation, including transportation connections, choices, cooperation and…
Intermontane basin An alluvium-filled valley between mountain ranges, often formed over a graben.
Internal Combustion Electric Power Plant The generation of electric power by a heat engine which converts part of the heat generated by combustion of the fuel into mechanical motion to operate an…
Internal Combustion Engine A conventional vehicle motor that burns fossil fuel in a chamber in the presence of air.
Internal Gain The heat produced by sources of heat in a building (occupants, appliances, lighting, etc).
Internal Mass Materials with high thermal energy storage capacity contained in or part of a building's walls, floors, or freestanding elements.
Internal Rate of Return A widely used rate of return for performing economic analysis. This method solves for the interest rate that equates the equivalent worth of an…
Interpretive site Information communicated via plaques, markers, and other methods, about the natural and/or cultural resources, their history and values, that are found at…
Interruptible load Energy loads that can be shut off or disconnected at the supplier's discretion or as determined by a contractual agreement between the supplier and the…
Interruptible or nonfirm transportation Transmission service that is reserved and scheduled on an as–available basis and is subject to curtailment or interruption.
Intertie The point of physical interconnection between adjacent transmission systems.
Intrinsic Layer A layer of semiconductor material (as used in a solar photovoltaic device) whose properties are essentially those of the pure, undoped, material.
Intrusive An igneous rock that forms under the Earth's surface. Examples include granite, diorite, and gabbro.
Invasive species Any species, including noxious and exotic species, that is an aggressive colonizer and can out-compete indigenous species.
Invertebrate An animal, such as an insect or mollusk, that lacks a backbone or spinal column.
Inverter A device that converts direct current electricity (from for example a solar photovoltaic module or array) to alternating current for use directly to…
Investment Tax Credit A tax credit granted for specific types of investments.
Investor Owned Utility (IOU) A power provider owned by stockholders or other investors; sometimes referred to as a private power provider, in contrast to a public power provider that…
Ion An atom or molecule that has lost or gained one or more electrons and has become electrically charged as a result.
Ionizer A device that removes airborne particles from breathable air. Negative ions are produced and give up their negative charge to the particles.