Index: A  B  C  D  E  F  G  H   K  L  M  N  O  P  R  S  T  U  V  W

AC (ALTERNATING CURRENT) The movement of an electric charge that periodically reverses direction. AC is the form in which electric power is delivered to homes and businesses.

ADVANCED METERING INFRASTRUCTURE (AMI) A type of a high technology electrical meter that identifies consumption in more detail than a conventional meter and communicates that information by way of a network back to local utility for monitoring and billing purposes. Commonly referred to as “Smart Meters.”

AIR CONDITIONER Equipment for air treatment used for air circulation, air cleaning, ventilation and heat transfer. Units usually contain a cooling coil or evaporator and a combination of an electrically-driven compressor and condenser.

AUTOMATIC (OR REMOTE) METER READING SYSTEM A structure that records the utilization of electricity, water and gas, and sends the data to a central data gathering mechanism.

BACKDRAFT A situation which can occur when a fire is starved of oxygen; consequently combustion ceases, but the fuel gases and smoke remain at high temperatures.

BLACKOUT The loss of power that impinging on many consumers of electricity over a large area for a considerable time period.

BLOWER DOOR TEST A special instrument used to measure air leakage in a building and its ductwork. The equipment is made of a temporary door covering which is installed in an outside doorway and a blower which forces air into or out of the building. The blower door measures how leaky the building and ductwork are, and can be used to find the location of the major leaks.

BROWNOUT When the utility decreases the voltage on the power lines in a controlled manner, so consumers receive a feeble electric current. If total power of demand surpasses the maximum supply available, a brownout can be used. The typical household will not notice the weaker electric current.

BTU (BRITISH THERMAL UNIT) The measure used to determine heat energy. One BTU will raise the temperature of one pound of water by one degree Fahrenheit at sea level. For instance, it takes 2,000 Btu to make one pot of coffee. One BTU compares to 252 calories, 778 foot-pounds, 1055 joules, and 0.293 watt-hours.

CALORIE (energy, as opposed to food) Any of several roughly equivalent measures of heat, each calculated as the amount of heat needed to elevate the temperature of 1 gram of water by 1 degree Celsius from a set initial temperature, esp. from 3.98 degrees Celsius, 14.5 degrees Celsius, or 19.5 degrees Celsius, at 1 atmosphere pressure. A calorie is the quantity of heat equal to 4.184 joules.

CFL (COMPACT FLUORESCENT LAMP) Also known as a compact fluorescent light or energy saving light. It is a type of fluorescent lamp and designed to replace the standard incandescent lamp. CFLs use less power and have a longer rated life.

CIRCUIT A complete set of electric conductors from a power outlet to other electrical devices and back to the same power outlet.

COMPETITIVE SERVICE PROVIDER A person or company licensed by the State Corporation Commission to sell competitive energy services in Virginia.

COOPERATIVE Electric cooperatives are private, independent electric utilities, owned by the members they serve.

DAYLIGHTING Using sunlight in place of electricity.

DAYLIGHTING CONTROL A system that controls electricity in response to variations in available daylight.

DC (DIRECT CURRENT) Electricity flowing in the same direction.

DEMAND The amount of electricity or natural gas delivered to consumers at a point in time. Expressed in kilowatts.

DEMAND BID indicates a quantity of energy or additional service that a qualified customer is willing to buy.

DEMAND BILLING Electric capacity specification for which a large user is responsible for financially. Can be based on the customer’s peak demand during the contract year, an agreed minimum, or previous maximum; measured in kilowatts.

DEMAND CHARGE the price a large consumer pays for its peak usage level.

DEMAND RESPONSE Programs designed to enable customers to contribute to energy load reductions during times of peak demand.

DEMAND-SIDE MANAGEMENT Programs designed to encourage consumers to modify their level and pattern of electricity usage to general y reduce demand.

DISTRIBUTION Electricity delivered to a customer’s abode through low voltage distribution lines.

DISTRIBUTION SERVICE The delivery of electricity directly to a home or business.

DOE (U.S. DEPARTMENT OF ENERGY) The federal department erected by the Department of Energy Organization Act to bring together the main federal energy operations into one cabinet-level department that would devise an all-inclusive, equitable national energy policy.

DUCTLESS MINI-SPLITS A heating and cooling solution for room additions or construction where extending or installing distribution ductwork is not feasible. Mini-splits can efficiently heat or cool individual rooms, saving energy and money.

ELECTRIC UTILITY A company or organization that delivers electric power to consumers. In Virginia electric utilities include investor owned, cooperatives, and municipally owned entities.

ELECTRICITY A property of the fundamental atoms of matter. Consists of energy that has magnetic, chemical and radiant effects. Electric current is created by a flow electrons (charged particles).

ELECTRICITY SUPPLY SERVICE The generation and transmission of electricity.

ENERGY CHARGE Money owed by an electric consumer for kilowatt-hours used.

ENERGY CONSUMPTION The amount of energy used in the form by which it is obtained by the consumer excluding electrical generation and distribution losses.

ENERGY EFFICIENCY Using less energy than usual to perform same job

EPA ( ENVIORNMENTAL PROTECTION AGENCY) A federal agency created in 1970 to authorize organized governmental action for preserve the environment by systematic reduction and control of pollution through assimilation or research, monitoring, setting standards and activities of enforcement.

EVACUATED TUBE A type of collector for a solar water heater containing a glass or metal tube that holds water or heat transfer fluid surrounded by a larger glass tube. The space between them is a vacuum, so very little heat is lost from the fluid.

FAN COIL Component of a heating, ventilation and air conditioning (HVAC) mechanism that includes a fan plus a heating or cooling coil, and used to allocate warm or cool air.

FUEL Used to produce electricity, including transportation.

GENERATION/SUPPLY The production of electricity at power plants fueled by various raw energy sources (nuclear, coal, oil, natural gas, etc.) or renewable energy sources (wind, solar, hydro, etc.). power plants.

HEATING SEASONAL PERFORMANCE FACTOR A depiction of the entire heating output of a central air-conditioning heat pump in BTUs during its regular usage time for heating, separated by the summation of electrical energy input in watt-hours during the same time period.

HVAC (HEATING VENTILATION AND AIR CONDITIONING) An entity that supplies heating, ventilation and/or cooling within or connected with a building.

HYDRONIC HEATING AND COOLING A type of radiant heating that uses water as the heat-transfer medium in heating and cooling systems. These systems use little electricity, which is a benefit for homes off the power grid or in areas with high electricity prices.

JOULE A unit of energy equivalent to the amount of work done when the point of application of force of 1 Newton is relocated 1 meter towards the force. It takes 1,055 joules to equal a British thermal unit.

kV (KILOVOLT) One-thousand volts (1,000). Electrical lines in housing areas usually are 12 kV (12,000 volts).

kW (KILOWATT) One thousand (1,000) watts. A form of measurement of the quantity of electricity needed to control given equipment.

kWh (KILOWATT-HOUR) The most commonly-used unit of measure giving the amount of electricity consumed over time. A 1,000-watt unit of electricity for one hour. A typical Virginia home may use approximately 1,000kWh in a month.

LDC (LOCAL DISTRIBUTION COMPANY) The public utility regulated by the State Corporation Commission that owns, maintains and operates the distribution lines and the equipment to deliver electricity to homes and businesses.

LED (LIGHT-EMITTING DIODE) LEDs are used as indicator lamps in many devices, especially for lighting. LEDs are based on the semiconductor diode. LEDs present many advantages over incandescent lights from lower energy consumption and longer life.

LOAD The amount of electric power supplied to meet one or more final user’s needs. –OR– An end-use device or an end-use customer that uses power. Loads different from demand.

LOAD DIVERSITY A situation that subsists when the peak demands of several electric customers happen at dissimilar times. This is the goal of “load molding” strategies, which curbs the total capacity requirements of a utility.

LOAD FACTOR A percent that tells the distinction between the amounts of electricity a customer has used during an amount of time and the amount that would have been used if the usage had stayed at the consumer’s highest demand level during the whole time. The term is also used to mean the percentage of capacity of an energy facility – such as power plant or gas pipeline – that is employed in a specific time period.

LOADING FACTOR Relation of electricity used and total potential consumption. Used when analyzing electricity consumption in an immense population. For example, a loading factor of 0.5 means that 50% of homes are using all of the electricity they are able or that, on average, all of the homes are only consuming 50% of the power they have the potential to consume.

LOAD MANAGEMENT Steps taken to decrease power demand at highest load times or to move some of it to off-peak times. This may be with allusion to peak hours, peak days or peak seasons. The main thing disturbing electric peaks is air-conditioning usage, which is therefore a major target for load management labors. Load management may be pursued by convincing consumers to change behavior or by using equipment that regulates some electric consumption.

METER A tool for gauging levels and volumes of a patron’s gas and electricity use.

MONTHLY ENERGY USAGE The amount of energy a household or business uses per month, expressed in kWh for electricity. Your energy bill may show your monthly energy usage for up to the past 12 months.

MULTIPLIER Some meters are programmed to document energy at a slower speed due to the amount needed. Once the readings are gained, the usage is increased by the programmed rate (multiplier).

MUNICIPAL UTILITY An electric or natural gas system owned and operated by a local government. In Virginia, municipal utilities are not regulated by the State Corporation Commission.

MW (MEGAWATT) One-thousand kilowatts (1,000 kW) or one million (1,000,000) watts.

MWh (MEGAWATT HOUR) One-thousand kilowatt-hours

NET METERING Net metering allows customers who generate excess electricity from renewable energy systems to receive the full retail value for their excess electricity at times when their system is producing more electricity than the building is consuming.

NET-ZERO These buildings use renewable energy to produce as much energy as they consume annually.

OUTAGE (Electric utility) a disruption of electric service that is momentary (minutes or hours) and affects a comparatively minute area (buildings or city blocks).

PARTIAL LOAD An electrical demand that uses only a fraction of the available electrical power.

PASSIVE HOUSE A well-insulated, virtually air-tight home that is primarily heated through collecting solar energy through windows and through natural gains from people and electrical systems.

PEAK LOAD OR PEAK DEMAND The electric load that correlates to the highest levels of electric demand in a precise period of time.

PFT (PERFLUOROCARBON TRACER GAS) AIR FILTRATION MEASUREMENT Measures changes over time (a few hours to several months) when determining a building’s air-infiltration rate. While this test cannot locate exact points of infiltration, it does reveal long-term infiltration problems. It can be used with or instead of the blower door test.

PHOTOVOLTAICS Photovoltaic (PV) systems are a common method of generating electrical power by converting solar radiation into direct current electricity.

POWER Electricity used as energy.

POWER PLANT A central generating facility that creates energy.

PRICE TO COMPARE The price per kWh of electricity supply service, to be used to contrast prices with competitive service providers.

R VALUE The R value or R-value is a measure of thermal resistance used in the building and construction industry.

RADIANT HEATING Technology that delivers heat directly from a hot surface to the people and objects in a room via infrared radiation. Radiant heating is often found in floor, wall or ceiling panels.

RATE SCHEDULE Value used to compute consumer’s bills.

REAL-TIME PRICING Electricity pricing that reflects its real-time cost.

RECOOL The rational cooling of air that has been formerly heated by HVAC mechanisms serving the same building.

RENEWABLE ENERGY Energy derived from sunlight, wind, falling water, sustainable biomass, energy from waste, municipal solid waste, wave motion, tides, and geothermal power, and does not include energy derived from coal, oil, natural gas or nuclear power.

RESISTANCE (electrical) the ability of all conductors of electricity to defy the flow of current, turning some of it into heat. Resistance relies on the cross section of the conductor (the smaller the cross section, the superior the resistance) and its temperature (the hotter the cross section, the more its resistance).

SCC (STATE CORPORATION COMMISSION) Virginia state government entity that oversees the state’s utilities.

SMART GRID Delivers electricity from suppliers to consumers using two-way digital technology to control appliances at consumers’ homes to save energy and reduce cost.

SMART METER A type of high technology electrical meter that identifies consumption in more detail than a conventional meter and communicates that information by way of a network back to local utility for monitoring and billing purposes. Also known as advanced metering infrastructure or AMI.

SOLAR POWER Electricity produced from solar radiation.

TARIFF A schedule of rates or charges of a public utility.

TAX CREDITS Credits established by the federal and state government to help in the expansion of the alternative energy industry.

TEMPERATURE Degree of warmth or coolness measured on one of many subjective scales based upon some phenomenon that can be observed.

THERMOGRAPHIC SCAN A diagnostic technique in which an infrared camera is used to measure temperature variations on the surface of the body, producing images that reveal sites of abnormal tissue growth.

THERMOSTAT A device that is designed to be receptive to temperature and used in upkeep of temperatures by going through the HVAC system.

THERMOSTAT, SETBACK A mechanism, that contains a time device, that can systematically change the inside temperature upheld by the HVAC system in relation to a preset schedule. The heating or cooling requirements can be condensed when a building is unoccupied or when inhabitants are slumbering.

TOU (TIME-OF-USE) METER A mechanism that measure and reports the times during which a patron uses varying degrees of electricity. This kind of meter is used for patrons who pay time-of-use rates.

TOU RATES Determining the price of electricity relating to the cost estimates of electricity usage during a specific amount of time. Time-of-use rates are typically separated into several time blocks per twenty-four hour time span (on-peak, off-peak, mid-peak, and sometimes super off-peak) and by seasons. Real-time pricing is different from TOU rates in that it is based on actual (as opposed to predicted) prices which may vary throughout the day and are sensitive to weather, rather than varying with a concrete schedule.

TRANSFORMER A mechanism, which through electromagnetic induction but without the use of moving parts, transforms changing or irregular electric energy in one circuit into energy of alike sorts in another circuit, usually used with changed values of current and voltage.

TRANSMISSION The movement of bulk energy supply from the generation facility to the local distribution company.

UA Amount of heat that can be transferred through a specified surface or enclosed space (such as a building envelope) with a one degree Fahrenheit temperature difference between the opposing sides. The UA is determined by multiplying the U-Value by the area of the surface (or multiple surfaces).

UPGRADE (Electric utility) Substitute or addition of electrical gear that concludes in higher generation or transmission holding ability.

VAV System (VARIABLE AIR VOLUME SYSTEM) A mechanical HVAC system responsible for serving multiple zones which control the temperature up kept in a zone by regulating the quantity of warm or cooled air supplied to the zone.

VENTILATION The process of providing or taking away available air by either mechanical or natural means to or from any area. The air may or may not have been previously treated.

VOLT A unit of electromotive power. It is the quantity of power necessary to force a stable current of one ampere through a resistance of one ohm. Electrical systems of most houses and offices have 120 volts.

VOLTAGE OF A CIRCUIT The electric force of a circuit, measured in volts. Typically a insignificant rating, based on the maximum normal effective disparity of potential between any two conductors of the circuit.

WARRANTY A seller’s guarantee to the buyer that the item for consumption is what it is represented to be and, if it is not, that it will be repaired or substituted. Within the context of vehicles, refers to an engine manufacturer’s guarantee that the engine will meet “certified” previously determined standards at 50,000 miles or the engine will be substituted. Retrofits may usually void an engine warranty.

WATER HEATER A mechanism used to provide hot water for reasons other than space heating or pool heating.

WATT A unit of measure of electric power at a specific point in time, at capacity or demand. One watt of power up kept over time is equivalent to one joule per second.

WATT-HOUR One watt of power exhausted for the span of one hour. One thousandth of a kilowatt-hour.

WHOLE HOUSE FAN A system that can cool a house by emitting a high volume of warm air when the outside air is cold.

WIND POWER Energy derived from wind.

Lesson Plans
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Get your students energized about responsible energy use! In partnership with the Virginia Department of Education, we’ve created fun, multi-day, Lesson plans to help you teach your students how to understand and conserve energy! They’re classroom-ready and free to use!