Glossary of Terms

Use this section as your guide to the terms and acronyms used in the energy world. Terms are listed alphabetically.

A

Alternative Energy: Energy derived from sources other than traditional non-renewable sources, such as coal, oil, and natural gas. Alternative energy typically refers to energy from renewable sources that do not harm the environment, such as solar or wind. Also, green power.
Alternative Fuel Vehicle (AFV): A vehicle designed to be powered by a fuel other than traditional gasoline. Alternative fuel typically refers to fuel from renewable sources that can be produced with minimal impact on the environment (e.g., compressed natural gas, methane blend, electricity). AFV’s can either be a dedicated vehicle designed to operate exclusively on alternative fuel or a non-dedicated vehicle designed to operate on alternative fuel and/or a traditional fuel.
Anaerobic Digestion (AD): The naturally occurring breakdown of organic materials by microorganisms when oxygen is not present. During this process, methane gas is created. An anaerobic digester is a man-made system that allows this process to happen more quickly and captures the methane that is released. This gas can be used to create heat and power. Animal waste, as well as food waste and municipal solid waste, can be used as AD feedstock.
Area Load: The total amount of electricity being used at a given point in time by all consumers in a specific geographic area. Typically used in reference to utility company territories.
Atmosphere: The mixture of gases surrounding the Earth. The Earth's atmosphere consists of about 79.1% nitrogen (by volume), 20.9% oxygen, 0.036% carbon dioxide and trace amounts of other gases.
Average Demand: The average amount of energy demand in a given geographical area over a period of time.

B

Base Load: The minimum amount of power production needed to power a specific geographic area during a specific amount of time. Typically used in reference to utility company territories.
Bi-Fuel Vehicle: A vehicle with two separate fuel systems designed to run on either fuel, using only one fuel at a time. Typically used by drivers who do not always have access to an alternative fuel station. Bi-fuel systems are usually used in light-duty vehicles. One of the two fuels is typically an alternative fuel.
Biodegradable: Capable of being decomposed by the action of biological agents, especially bacteria.
Biodiesel: A fuel made from plant-based fats and oils. It has a chemical form that makes it compatible with compression ignition in a diesel engine. Biodiesel comes in different concentrations: B100 is 100% plant-based biodiesel, B20 is 20% plant-based biodiesel and 80% petroleum diesel. You may see other blends such as B50 or B5; however, B100 and B20 are the most common.
Biofuels: Biofuel is broadly defined as solid, liquid, or gas fuel consisting of or derived from biomass (e.g. biodiesel, ethanol).
Biomass: Organic matter that is derived from wood, plants, agricultural residues, animal waste, and the organic components of municipal and industrial wastes. These materials can be used to produce electricity, transportation fuels (biofuels), or chemicals for consumer products.
Blackout: A power loss affecting many electricity consumers over a large geographical area for a significant period of time.
Brownout: A controlled power reduction in which the utility decreases the voltage on the power lines, so customers receive weaker electric current. Brownouts can be used if total power demand exceeds the maximum available supply. The typical household does not notice the difference.

C

CAMU: The Colorado Association of Municipal Utilities. CAMU is a non-profit organization that represents the 32 cities and towns throughout Colorado that own and operate their own electric and natural gas systems.
Capacity: The amount of electric power for which a generating unit, generating station, or other electrical apparatus is rated either by the user or manufacturer. The term is also used for the total volume of natural gas that can flow through a pipeline over a given amount of time, considering such factors as compression and pipeline size.
Carbon Dioxide (CO2): A colorless, odorless, non-poisonous gas that is a normal part of Earth’s atmosphere. Carbon dioxide, also called CO2, is exhaled by humans and animals and is absorbed by green growing things and by the sea.
Carbon Monoxide: A colorless, odorless, highly poisonous gas made up of carbon and oxygen molecules formed by the incomplete combustion of carbon or carbonaceous material, including gasoline.
CFCs (Chlorofluorocarbons or Chlorinated Fluorocarbons): A family of man-made chemicals receiving much attention for their role in ozone depletion. Since they were introduced in the mid-1930s, CFCs have been used as refrigerants, solvents and in the production of foam material.
Climate Change: Any long-term significant change in the weather patterns of an area, or the Earth when referring to global climate change.
Co-generator: Co-generators use the waste heat created by one process, for example during manufacturing, to produce steam which is used, in turn, to spin a turbine and generate electricity.
Coal: Black or brown rock, formed under pressure from organic fossils in prehistoric times. Coal is mined and burned to produce heat energy.
Combined Cycle Plant: An electric generating station that uses waste heat from gas turbines to produce steam for conventional steam turbines.
Combined Hydronic Space/Water Heating: A system in which both space heating and domestic water heating are provided by the same water heater(s).
Compact Fluorescent Lights (CFL’s): A type of light bulb that uses about 25% of the energy that an incandescent bulb uses while giving off the same amount of light and lasting up to 10 times longer. There are a variety of CFL options when it comes to color, lighting quality, shape, and wattages. Many CFL's are designed to replace an incandescent lamp and can fit in the existing light fixtures formerly used for incandescents.

D

Demand: The level at which a utility company delivers electricity or natural gas to users at a given point in time. Electric demand is expressed in kilowatts.
Department of Energy (DOE): A federal government department whose mission is to advance energy technology and promote related innovation in the United States
Depletable Energy Sources: 1) electricity purchased from a public utility 2) energy obtained from burning coal, oil, natural gas or liquefied petroleum gases.

E

E85: "E85" is a renewable transportation fuel that is composed of 85 percent ethanol and 15 percent petroleum.
Ecological Footprint: The impact a human has on the environment created by their use of land, water, and other natural resources. Usually calculated in terms of area of planet needed to sustain consumption.
Ecosystem: Includes the interaction between a biological community and its nonliving environment.
Electric Vehicle (EV): A vehicle powered by electricity, usually provided by batteries but may also be provided by photovoltaic (solar) cells or a fuel cell.
Emissions Standard: The maximum amount of a pollutant legally permitted to be discharged from a single source.
Energy Audit: An energy audit identifies where a building is leaking energy, determines how well heating and cooling systems are working, and identifies what actions are needed to take to fix any problems uncovered throughout the process.
Energy Eficiency: Using less energy/electricity to perform the same function.
Energy Star: A voluntary labeling program of the US Environmental Protection Agency (EPA) and the US Department of Energy (DOE) that identifies energy efficient products. Qualified products exceed minimum federal standards for energy consumption by a certain amount, or where no federal standards exist, have certain energy saving features. Products that meet ENERGY STAR requirements typically display an ENERGY STAR label.
Environmental Impact Assessment (EIA): An assessment of the likely positive and/or negative influence a project may have on the environment.
Environmental Protection Agency: An independent federal agency, created in 1970, which sets and enforces rules and standards that protect the environment and control pollution.
ESCO (Energy Service Company): A company that offers to reduce a client's electricity consumption with the cost savings being split with the client.
Ethanol: Ethanol is an alcohol-based alternative fuel produced by fermenting and distilling starchy crops that have been converted into simple sugars. Feedstocks include corn, sugar beets, sugar cane, sorghum, barley, and wheat. Ethanol is most commonly used to increase octane and improve the emissions quality of gasoline.

F

Federal Energy Regulatory Commission (FERC): An independent regulatory commission within the U.S. Department of Energy.
Fermentation: Fermentation can be used to produce ethanol from biomass. In this process, starch from plants is converted to sugar and fermented into ethanol, which is then distilled in its pure form.
Flexible Fuel Vehicle (FFV): A vehicle that can operate on either alcohol fuels (methanol or ethanol) or regular unleaded gasoline or any combination of the two from the same tank.
Fossil Fuel: Oil, coal, natural gas or their by-products. These materials formed in the earth in prehistoric times from remains of living-cell organisms.
Fuel Cell: A device with no moving parts that converts the chemical energy of a fuel, such as hydrogen, and an oxidant, such as oxygen, directly into electricity.
Fuel Oil: Petroleum products that are burned to produce heat or power.

G

Gasification: Gasification converts biomass to what is commonly called a "producer gas" by heating the raw material at high temperature with a controlled amount of oxygen. The resulting producer gas can be combusted to generate electricity, heat and liquid fuels.
Geothermal Energy: Energy generated from the natural heat that is stored beneath the Earth's surface and carried by steam or hot water. It can generate electricity or be used directly to heat and cool buildings.
Gigawatt (GW): One billion watts (1,000,000,000 W) or one million kilowatts (1,000,000 kW) of electricity. One GW is enough to supply the electric demand of about one million average Colorado homes.
Gigawatt-Hour (GWH): One billion watts of electric electricity supplied for one hour.
Global Climate Change: Gradual changing of global climates due to buildup of carbon dioxide and other greenhouse gases in the earth's atmosphere. This happens when the carbon dioxide produced by burning fossil fuels has reached levels greater than what can be absorbed by green plants and the seas.
Green Building: The practice of increasing the efficiency with which buildings and their sites use and harvest energy, water, and materials, and reducing building impacts on human health and the environment, through better site selection, design, construction, operation, maintenance, and removal.
Greenhouse Effect: rapping and build-up of heat in the atmosphere (troposphere) near the Earth's surface. Some of the heat flowing back toward space from the Earth's surface is absorbed by water vapor, carbon dioxide, ozone, and several other gases in the atmosphere and then reradiated back toward the Earth's surface. If the atmospheric concentrations of these greenhouse gases rise, the average temperature of the lower atmosphere will gradually increase.
Greenhouse Gas (GHG): Any gas that absorbs infrared radiation in the atmosphere. Greenhouse gases include, but are not limited to, water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), ozone (O3), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).
Grid: Referring to the utility grid. The system of power plants, transmission lines, meter readers, and monthly bills that is responsible for keeping our lights on.

H

Heat Gain: An increase in the amount of heat contained in a space, resulting from direct solar radiation, heat flow through walls, windows, and other building surfaces, and the heat given off by people, lights, equipment, and other sources.
Heat Loss: A decrease in the amount of heat contained in a space, resulting from heat flow through walls, windows, roof and other building surfaces.
High Performance Design (HPD): Designing a building to perform efficiently and actively managing the building's operations to optimize performance.
Hybrid Vehicle: A vehicle that employs a combustion engine system together with an electric propulsion system. Hybrid technologies expand the usable range of electric vehicles beyond what an all-electric-vehicle can achieve with batteries only.
Hydrolysis: Hydrolysis involves extracting simple carbohydrates from complex carbohydrates found in cellulose and hemicellulose. Extracting the carbohydrates may involve "steam explosion" of the cell walls, or dissolving the organic constituents with acids, enzymes, or organic solvents. Sugars resulting from hydrolysis can then be converted into ethanol through microbial fermentation.

I

Incandescent Lamp: An electric lamp in which a filament is heated by an electric current until it emits visible light.
Industrial: An energy-consuming sector that consists of all facilities and equipment used for producing, processing, or assembling goods. The industrial sector encompasses the following types of activity: manufacturing, agriculture, forestry, and fisheries, mining, including oil and gas extraction, natural gas transmission, and construction. Overall energy use in this sector is largely for process heat and cooling and powering machinery, with lesser amounts used for facility heating, air conditioning, and lighting. Fossil fuels are also used as raw material inputs to manufactured products
Investor Owned Utility (IOU): A private company that provides a utility, such as water, natural gas or electricity, to a specific service area. There are two IOU's in Colorado; Xcel Energy and Aquila.

K

Kilowatt (kW): One thousand (1,000) watts. A unit of measurement used to communicate the amount of electricity needed to operate something. For example, a typical hair dryer will use about 1 kW at high setting.
Kilowatt Hour (kWh): A unit of measurement used to communicate the amount of electricity needed to operate something over one hour. One kilowatt of electricity supplied for one hour.

L

Lignt Emitting Diodes (LEDs): An efficient lighting option. LEDs create light without releasing heat, are more efficient, last longer than compact fluorescent lights, and don’t contain mercury. While LEDs are most commonly used for accent lighting and outdoor applications, LED light bulbs are now becoming available to consumers for household lighting.
Load: The amount of electric power supplied to meet one or more end user's needs.
Lumen: A measure of the amount of light available from a light source equivalent to the light emitted by one candle.

M

Megawatt (MW): One-thousand kilowatts (1,000 kW) or one million (1,000,000) watts. A unit of measurement used to communicate the amount of electricity needed to operate something. For example one megawatt is enough electricity to power 1,000 average Colorado homes.
Meter: A device that keeps track of how much electricity is being used. Utility companies use meters to determine how much to charge a customer each billing period.
Methane (CH4): A light hydrocarbon that is the main component of natural. It is the product of the anaerobic decomposition of organic matter, enteric fermentation in animals and is one of the greenhouse gases.
Municipal Utility: A type of utility service provider that is owned and operated by a municipal government.

N

Natural Gas: A gaseous fossil fuel found in the earth composed of methane, ethane, butane, propane and other gases. Natural gas can be used for heat and electricity.
Natural Gas Vehicle (NGV): Vehicles that are powered by compressed or liquefied natural gas.
Net Metering: A policy for energy providers. Under net metering, a system owner receives retail credit for at least a portion of the electricity they generate with home generation technology, such as solar panels. Net metering allows home power systems to essentially sell power back to the grid.
Nuclear Energy: Power obtained by splitting heavy atoms (fission) or joining light atoms (fusion). A nuclear energy plant uses a controlled atomic chain reaction to produce heat. The heat is used to make steam run conventional turbine generators.

O

Outage: An interruption of electric service that is temporary (minutes or hours) and affects a relatively small area (buildings or city blocks).
Ozone: A kind of oxygen that has three atoms per molecule instead of the usual two. Ozone is a poisonous gas, but the ozone layer in the upper atmosphere shields life on earth from deadly ultraviolet radiation from space. The molecule contains three oxygen atoms (O3).

P

Partial Load: An electrical demand that uses only part of the electrical power available.
PCBs (Polychloronated Biphenyls): A group of organic compounds used to manufacture plastics. In the environment, PCBs are highly toxic to aquatic life. They persist in the environment for long periods of time and are biologically accumulative.
Peak Load: The highest electrical demand within a particular period of time. For example, daily demand peaks on weekdays occur in late afternoon and early evening; annual peaks occur on hot summer days.
Photovoltaic (PV): Converting light to electricity. PV panels are composed of cells that contain a semi-conducting material, usually silicon.The semi-conducting material absorbs light energy from the sun and converts it into electricity.
Post-Consumer Waste: Used materials that are diverted from landfill waste for the purpose of collection, recycling, and disposition. Products made from recycled material contain a certain percentage of post-consumer waste.
Power Authorities: Quasi-governmental agencies that perform all or some of the functions of a public utility.
Pre-Consumer Waste: Materials generated in manufacturing and converting processes that never reach consumers, such as scrap, trimmings, and cuttings.
Pyrolysis: The process of heating biomass at a high temperature in the absence of oxygen. It can be broken down into three main products: liquid oil, char and a combustible gas.

R

Renewable Energy: Energy that comes either directly or indirectly from a source that is essentially inexhaustible unlike, for example, fossil fuels, of which there is a finite supply. Renewable sources of energy include wood, waste, geothermal, wind, and solar.
Renewable Resources: Resources that are replenished naturally, unlike, for example, fossil fuels.
Renewables: Energy obtained from sources that are essentially inexhaustible, unlike, for example, fossil fuels, of which there is a finite supply. Renewable sources of energy include wood, waste, geothermal, wind, photovoltaic, and solar thermal energy.
Residential Building: Any apartment house, single dwelling, or other building that is used as living quarters.
Resource Efficiency: he use of smaller amounts of resources to produce the same product or service. Resource efficiency involves a concern for the use of all physical resources and materials used in the production and use cycle, not just the energy input.
Resource Mix: Profile of where utility gets its power from (% of coal, solar, wind, etc.)
Retrofit: Broad term that applies to any change after the original purchase of a building; adding equipment not a part of the original purchase. As applied to alternative fuel vehicles, it refers to conversion devices or kits for conventional fuel vehicles.
Rural Electric Cooperative: A utility company that is owned and operated by a collective group.

S

Solar Cell: A photovoltaic cell that can convert light directly into electricity. A typical solar cell uses semiconductors made from silicon.
Solar Energy: Heat and light radiated from the sun.
Solar Thermal: Solar thermal systems function relatively simply; heat from the sun is collected in sealed tubes that contain a liquid. The liquid acts as a heat transfer. The heat from the sun warms up the liquid and the liquid is carried from the collector through a heat exchanger into a storage tank. The storage tank holds the water until it is needed for domestic use (showers, laundry, etc.) or for space heating.

T

Transfer: To move electric energy from one utility system to another over transmission lines.
Transmission: Transporting bulk power over long distances.
Turbine Generator: A device that uses steam, heated gases, water flow or wind to cause spinning motion that activates electromagnetic forces and generates electricity.

U

Unleaded Gasoline: Gasoline that has had tetraethyl lead removed in conformance with federal and state regulations.
Utility: A regulated entity that maintains the infrastructure for a public service, such as providing electricity.

V

Volt: A unit of measurement used to communicate how much force an electrical current has. It is the amount of force required to drive a steady current of one ampere through a resistance of one ohm. Electrical systems of most homes and office have 120 volts.

W

Waste Heat Recovery: Any conservation system whereby some space heating or water heating is done by actively capturing byproduct heat that would otherwise be ejected into the environment.
Watt: A unit of measurement used to communicate the amount of electricity needed to operate something. For example, a typical incandescent light bulb uses between 60 and 100 watts.
Watt-Hour: One watt of power expended for one hour.
Wind Farm: A group of wind turbines in the same location used for production of electric power.
Wind Power: Electricity generated through the harnessing of wind energy using a turbine generator.
Wind Power Plant: A group of wind turbines interconnected to a common utility grid through a system of transformers and distribution lines.
Wind Turbine: An energy conversion device that produces electricity by harnessing energy from the wind using a turbine generator; typically three blades rotating about a horizontal axis.

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