TXU - Glossary of Terms

Home

Contact TXU

Site Map

Responsibility Picture

Committed to environmental excellence and community involvement.

About TXU

Investor Resources

News

Responsibility

Careers

Educational Resources

Generating Electricity

Delivering Electricity

Electrical Safety Tips

Glossary of Terms

Business Continuity

Glossary of Terms

affiliate rules
Under The Texas Electric Choice Act, safeguards to govern the interaction between regulated utilities and their affiliates, during the transition to and after the launch of competition, to avoid cross-subsidization and sharing of confidential customer information.

anode
the positive electrode toward which negative particles (anions, electrons) move within devices like battery cells, electrolytic cells and diodes.

battery
any energy-storage device allowing release of electricity on demand. It consists of one or more electrical cells. Primary-cell batteries are disposable; secondary-cell batteries, or accumulators, are rechargeable. Primary-cell batteries are an extremely uneconomical form of energy, since they produce only 2 percent of the power used in their manufacture. The lead-acid car battery is a secondary-cell battery. The car's generator continually recharges the battery. It consists of sets of lead (positive) and lead peroxide (negative) plates in an electrolyte of sulfuric acid (battery acid). The introduction of rechargeable nickel-cadmium batteries has revolutionized portable electronic newsgathering (sound recording, video) and information processing (computing). These batteries offer a stable, short-term source of power, free of noise and other electrical hazards.

bauxite
the raw material mined from the earth used to make aluminum.

biodegradable
capable of being broken down by living organisms, principally bacteria and fungi.

biomass
energy derived from plants. Alcohol fuels are produced from wood, sugarcane and corn. Firewood, crop residue and cattle dung can also be burned as biomass fuel. As long as the amount of plants regrown equals the amount of fuel burned there will be no additional carbon dioxide produced to contribute toward global warming.

British Thermal Unit (BTU)
a measure of energy in the English system measurement, roughly the amount of heat required to raise one pound of water one degree Fahrenheit. This unit of measuring heat will soon no longer be used and will be replaced by "joule."

calorie
currently the most common unit for measuring heat and soon to be replaced by joules. The calorie is the amount of energy required to raise the temperature of one cubic centimeter of water one degree Celsius (formerly called centigrade). The calorie is from the Latin word "calor" meaning "heat." It is equivalent to 4.185 joules. It is important not to confuse the word calorie (small c) with Calorie (capital C). A Calorie (or kilocalorie) describes the available energy in food. It is the amount of heat required to raise the temperature of 1,000 grams (Kilogram) of water by 1 degree Celsius. Physicist Paul Hewitt put it this way: "To the weight watcher, the peanut contains 10 Calories. To the physicist, it releases 10,000 calories (or 41,850 joules) of energy when burned or digested."

capacity auction
Under The Texas Electric Choice Act, electric utilities in the State of Texas are required to auction entitlements to 15 percent of the electric utility's Texas jurisdictional installed generation capacity for 60 months or until a certain amount of customers have acquired power from another retail electric provider.

carbon dioxide (CO2)
a colorless, odorless, nonflammable gas formed during decomposition, combustion and respiration. CO2 appears in food refrigeration (dry ice), carbonated beverages (the bubbles and fizz), fire extinguishers and aerosol cans. Whenever something burns -- such as gasoline, wood or a candle -- CO2 results from the available oxygen combined with the carbon in the fuel.

carbon monoxide (CO)
colorless, odorless gas formed when carbon oxidizes in a limited supply of air. It is a poisonous constituent of car exhaust fumes, forming a stable compound with hemoglobin in the blood, thus preventing the hemoglobin from transporting oxygen to the body tissues.

chlorofluorocarbon (CFC)
synthetic chemical that is odorless, nontoxic, nonflammable, and chemically inert. CFCs have been used as propellants in aerosol cans, as refrigerants in refrigerators and air conditioners, and in the manufacture of foam packaging. They are partly responsible for the destruction of the ozone layer.

coal
a form of stored solar energy. It results from the remains of plants that have been concentrated by heat and pressure for millions of years. Coal appears in various forms or "grades," which depend on the ratio of carbon mass to energy content. Represented in descending order of hardness and energy content per pound, these grades are anthracite, bituminous, sub-bituminous and lignite.

cogeneration
the use of waste heat from an electrical generating plant for other purposes, such as heating. Also, the use of waste heat from a high-temperature industrial process to generate electricity.

crude oil
petroleum direct from the ground, prior to refinement or processing.

Customer Choice
Under The Texas Electric Choice Act, the freedom of a retail customer to purchase electric services, either individually or through voluntary aggregation with other retail customers, from the provider(s) of the customer's choice and to choose among various fuel types, energy efficiency programs, and renewable power suppliers.

Customer Education Plan
At the beginning of 2001, the Public Utilities Commission of Texas will begin a campaign to educate customers about the newly restructured electric industry. TXU is engaged in its own customer education campaign, as well.

Customer Protection
Before customer choice begins in Texas on January 1, 2002, the Public Utilities Commission of Texas must ensure that retail customer protections are established. These protections must entitle a customer to safe, reliable, and reasonably priced electricity; a bill presented in a clear format; the option to have all electric services on a single bill; protection from discrimination; accuracy of metering and billing information in any language necessary.

distribution
the facilities of the electric system that deliver electricity from substations to customers. The distribution system "steps down" power from high-voltage transmission lines to a level that can be used in homes and businesses.

ecology
study of the relationship among organisms and the environments in which they live, including all living and nonliving components.

efficiency
the amount of work output compared to the quantity of energy input. One can increase efficiency by either increasing the amount of work accomplished or by decreasing the energy expended to accomplish that work. Nothing is 100 percent efficient. An incandescent light bulb is very inefficient as a source of light, yet it is a good source of heat.

electrodynamics
the branch of physics dealing with electric currents and associated magnetic forces. Quantum electrodynamics (QED) studies the interaction between charged particles and their emission and absorption of electromagnetic radiation. This field combines quantum theory and relativity theory, making accurate predictions about subatomic processes involving charged particles such as electrons and protons.

electric current
the flow of electronically charged particles through a conducting circuit due to the presence of a potential difference. The current at any point in a circuit is the amount of charge flowing per second; its SI unit is the ampere (coulomb per second).

electricity
a property of matter created by the movement of electrons. This "movement" is initiated usually by a generator fueled by any number of energy resources such as coal, uranium, water (hydropower), or directly converted from solar radiation in photovoltaic cells. Electricity is not energy per se, but the "carrier" of energy that originates in fossil fuel and renewable energy sources.

electromagnetic waves
oscillating electric and magnetic fields traveling together through space at a speed of nearly 186,000 mi/300,000 km per second. The (limitless) range of possible wavelengths or frequencies or electromagnetic waves, which one can think of as making up the electromagnetic spectrum, includes radio waves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

electron microscope
instrument that produces a magnified image by using a beam of electronics instead of light rays, as in a optical microscope. An electron lens is an arrangement of electromagnetic coils that control and focus the beam. Electrons are not visible to the eye, so instead of an eyepiece there is a fluorescent screen or photographic plate on which the electrons form an image. The wavelength of the electron beam is much shorter than that of light, so much greater magnification and resolution (ability to distinguish detail) can be achieved. The development of the electron microscope has made possible the observation of very minute organisms, viruses and even large molecules.

electronics
branch of science that deals with the emission of electronics from conductors and semiconductors, with the subsequent manipulation of these electronics, and with the construction of electronic devices. The first electronic device was the thermionic valve, or vacuum tube, in which electrons moved in a vacuum, and led to such inventions as radio, television, radar and the digital computer. Replacement of valves with the comparatively tiny and reliable transistor in 1948 revolutionized electronic development. Modern electronic devices are based on minute integrated circuits or silicon chips, wafer-thin crystal slices holding tens of thousands of electronic components.

Electric Reliability Council of Texas (ERCOT)
one of 10 regional Reliability Councils in the North American Electric Reliability Council (NERC) Organization responsible for security monitoring and ensuring reliability of the electric system. ERCOT is also charged with overseeing functions such as settlement and registration in the competitive market. ERCOT is an area located totally within the State of Texas that contains about 85 percent of Texas's electrical load.

embodied energy
Embodied energy is associated with the production of a good or service or the energy to prepare or make a product. Using french fries as an example, substantial energy occurs in the planting, cultivation and harvesting of the potatoes. Then energy is occurs in the preparation of the french fries' packaging, transportation, marketing, storing, cooking and serving to a hungry teenager. One can reduce embodied energy by limiting food processing, or by recycling.

energy
capacity for doing work. Potential energy (PE) is energy deriving from position; thus a stretched spring has elastic PE, and an object raised to a height above the Earth's surface, or the water in an elevated reservoir, has gravitational PE. A lump of coal and a tank of gasoline, together with the oxygen needed for their combination, have chemical energy. Other sorts of energy include electrical and nuclear energy, and light and sound. Moving bodies possess kinetic energy (KE). Energy can be converted from one form to another, but the total quantity stays the same (in accordance with the conservation of energy principle). For example, as an apple falls, it loses gravitational PE but gains KE. Although energy is never lost, after a number of conversions it tends to finish up as the kinetic energy of random motion of molecules (of the air, for example) at relatively low temperatures. This is "degraded" energy in that it is difficult to convert it back to other forms.

energy conservation
methods of reducing energy use through insulation, increasing energy efficiency and changes in patterns of use. Profligate energy use by industrialized countries contributes greatly to air pollution and the greenhouse effect when it draws on nonrenewable energy sources.

Energy Industry Ombudsman
The Energy Industry Ombudsman in Australia’s Victoria state has the power to investigate and resolve disputes between Victorian electricity and gas customers and their energy companies.

environment
Scottish historian and essayist Thomas Carlyle introduced the word "environment" in the 19th century to define our surroundings. In the 17th century, "environs" meant your neighborhood. Today, your "neighborhood" has reached global proportions, so much so that technology and energy consumption far removed from our community can alter the vitality of our atmosphere, ocean and land.

Federal Energy Regulatory Commission (FERC)
commission enacted by the U.S. federal government in 1935 to oversee interstate electricity transmission and establish wholesale electricity rates.

fission
In 1939, exiled German physicist Lise Meitner theorized that when a neutron hits a uranium nucleus, it splits the nucleus into two parts. She was soon proven correct, and the reaction was called "fission" from the Latin word meaning "to split." The process releases large amounts of energy that can be used to boil water, create steam, turn a generator and generate electricity.

fossil fuel
fuel such as coal, oil and natural gas formed from the fossilized remains of plants that lived hundreds of millions of years ago. Fossil fuels are a nonrenewable resource and will eventually run out. Extraction of coal and oil causes considerable environmental pollution, and burning coal contributes to problems of acid rain and the greenhouse effect.

fuel chain
the chain of activities involved in transforming energy into forms more convenient for society. This chain may include some or all of the following: fuel exploration, extraction, preparation, transportation, conversion to electricity, distribution and waste disposal.

fusion
derived from the Latin word "fusus" meaning "to melt." Fusion involves releasing an enormous amount of energy by joining the nuclei of small atoms. Fusion was considered by scientists as a possible energy source long before fission.

generation (electricity)
the process of producing electrical energy from other forms of energy; also, the amount of electric energy produced, usually expressed in kilowatt-hours (kWh) or megawatt-hours (MWh).

geophysics
branch of earth science using physics to study the Earth's surface, interior and atmosphere. Studies also include winds, weather, tides, earthquakes and volcanoes and their effects.

geothermal power
the natural heat of the Earth that is conducted or convected to the Earth's surface through volcanoes and hot springs. By harnessing this energy and using it to power steam turbines, we can convert geothermal energy into electricity that we can use.

grid
the transmission network (or "highway") over which electricity moves from suppliers to customers.

habitat
in ecology, the localized environment in which an organism lives. Habitats often get described by the dominant plant type or physical feature, such as a grassland habitat or rocky seashore habitat.

heat
form of internal energy possessed by a substance by virtue of the kinetic energy in the motion of its molecules or atoms. Heat energy is transferred by conduction, convection and radiation. It always flows from a region of higher temperature (heat intensity) to one of lower temperature. Its effect on a substance may be simply to raise its temperature or to cause it to expand, melt (if a solid), vaporize (if a liquid) or increase its pressure (if a confined gas).

hydrocarbons
an extensive group of chemicals that always include the elements hydrogen and carbon. Natural sources of hydrocarbons are the by-products of digestion and decomposition (e.g., rotting, spoiling, putrefying). Coal, natural gas, oil, sugar, starches, and plastics are all composed of hydrocarbons. The incomplete combustion of hydrocarbons from fossil fuels contributes to our pollution and global warming problems.

hydroelectric power (HEP)
electricity generated by moving water. In a typical HEP scheme, water stored in a reservoir, often created by damming a river, gets piped into water turbines and coupled to electricity generators. In pumped storage plants, water flowing through the turbines is recycled.

hydropower
Hydropower is the use of the potential energy contained in water behind dams. Release of water through dam spillways converts potential energy into kinetic energy, which then helps turn a turbine and create power that we can use.

Independent Power Producers (IPPs)
In the United States, this term includes, but is not limited to, cogenerators and small power producers and all nonutility electricity producers, such as exempt wholesale generators who sell electricity.

Independent System Operator (ISO)
in the U.S. competitive environment, an entity that will be established to ensure open access to the transmission and distribution system in ERCOT. The ISO will be supported through a small charge that all customers will pay.

joule
named in honor of British physicist James P. Joule (rhymes with pool) who proved in 1843 that a specific amount of work was converted into a specific amount of heat. A joule (j) is now a unit for all forms of energy. One joule of work occurs when the force of one NEWTON is exerted on an object moving in the direction of the force, a distance of one meter. It takes about one joule to lift an apple over your head. As the transition from the English system of energy measurement to the international system of units (SI) picks up momentum, we will soon become accustomed to hearing more frequently of kilojoules (Kj) and megajoules (Mj). One kilowatt-hour = 3.6 x 106 joules. One calorie = 4.187 joules.

kilowatt
a measure of electric energy equal to 1,000 watts. Put another way, it's the amount of electric energy required to light ten 100-watt light bulbs.

kilowatt-hour
a measure of electricity consumption equivalent to the use of 1,000 watts of power over a period of one hour. Ten 100-watt light bulbs, burning for one hour would consume one kilowatt-hour of electricity.

kinetic energy
the energy of motion. If an object is in motion, it is capable of doing work.

light
electromagnetic waves in the visible range, having a wavelength from about 400 nanometers in the extreme violet to about 770 nanometers in the extreme red. Light is considered to exhibit particle and wave properties, and the fundamental particle, or quantum, of light is called the photon. The speed of light (and of all electromagnetic radiation) in a vacuum is approximately 186,000 mi/300,000 km per second, and is a universal constant denoted by c.

luminescence
emission of light from a body when its atoms are excited by means other than raising its temperature. Short-lived luminescence is called fluorescence.

magnetism
phenomena associated with magnetic fields. Magnetic fields are produced by moving charged particles: in electromagnets, electrons flow through a coil of wire connected to a battery; in permanent magnets, spinning electrons within the atoms generate the field.

megawatt
a unit of power equal to 1 million watts. Put another way, it's the amount of electric energy required to light 10,000 10-watt bulbs.

megawatt-hour(mWh)
1 million watts used for one hour. If you purchased a megawatt-hour of energy for a nickel per kilowatt-hour, it would cost you 1,000 nickels, or $50. Using a kWh your could burn one 100-watt incandescent for 24 hours a day for about 14 months, or 3 hours a day for over 9 years.

methane (CH4)
derived from the Greek word "methy" meaning wine. The early Greeks believed if they drank wine from cups carved from the crystal amethyst they could not become intoxicated (Greek "methyein"). Methane is a simple hydrocarbon composed of one carbon atom surrounded by four hydrogen atoms. It is an odorless, flammable and invisible gas and the primary ingredient in natural gas. Natural gas companies add a strong odorant to the gas for safety so it can be easily detected by smell. Methane is a relatively clean fuel, and it is commonly used to fuel vehicles in many countries, such as New Zealand and Italy.

municipal utility
(also known as a municipally owned electric system)

a municipal utility is owned and operated by a city. In most cases, municipal utility rates are set at the city level, either by the municipal administration or by a local utility board or commission. In some limited circumstances, state-level regulations apply.

Municipal utilities often have access to low-cost power from federal hydroelectric projects and can obtain low interest loans, and they are exempt from income and other taxes at the federal and state levels. These factors contribute to lower financing costs for plant and equipment. Municipal utilities serve roughly 14 percent of the nation's electric customers.

natural gas
a mixture of flammable gases found in the Earth's crust (often in association with petroleum), now one of the world's three main fossil fuels (with coal and oil). Natural gas is a mixture of hydrocarbons, chiefly methane, with ethane, butane and propane.

natural gas
See methane.

neutron
one of the three chief subatomic particles (the others being the proton and the electron). Neutrons have about the same mass as protons but no electric charge and occur in the nuclei of all atoms except hydrogen. They contribute to the mass of atoms but do not affect their chemistry, which depends on the proton or electron numbers. For instance, isotopes of a single element (with different masses) differ only in the number of neutrons in their nuclei and have identical chemical properties.

New South Wales Ministry of Energy and Utilities
One of the Ministry of Energy and Utilities' (MEU's) roles is to provide strategic policy advice to the minister for the management and use of New South Wales energy resources in the competitive national energy markets. The MEU takes a leading role in gas reform. Also, the MEU has oversight responsibility of electricity network operators and the greenhouse gas reduction requirements of electicity retailers.

North American Electric Reliability Council (NERC)
a non-profit organization formed by the electric utility industry to ensure a reliable, adequate power supply in North America. NERC plays an important role in establishing the standards, rules and forms of cooperation that contribute to system reliability.

NERC was formed in 1969 and consists of 10 regional councils comprised of individual electric utilities in the United States, Canada and Mexico. The transmission systems of the members of these regional councils interconnec, creating flexible regional systems that allow the transfer of power among areas to maintain one of the world's most reliable electric systems.

nuclear energy
>energy from the inner core or nucleus of the atom, as opposed to energy released in chemical processes, which derives from the electrons surrounding the nuclei. Nuclear fusion is the release of thermonuclear energy by the conversion of hydrogen nuclei to helium nuclei, in a continuing reaction in the sun and other stars. Nuclear fusion is the principle behind thermonuclear weapons. Attempts to harness fusion for commercial power production have so far not succeeded.

nuclear fission
process whereby an atomic nucleus breaks up into two or more major fragments with the emission of two or three neutrons. It is accompanied by the release of energy in the form of gamma radiation and the kinetic energy of the emitted particles.

nuclear fusion
process where two atomic nuclei are fused, with the release of a large amount of energy. Extremely high temperatures and pressures are thought to be required for the process to happen. Under these conditions the atoms involved are stripped of all their electrons so that the remaining particles, which together make up plasma, can come close together at high speeds and overcome the mutual repulsion of the positive charges on the atomic nuclei.

At close range, another nuclear force will come into play, fusing the particles together to form a larger nucleus. As fusion is accompanied by the release of large amounts of energy, the process might one day be harnessed to form the basis of commercial energy production. Methods of achieving controlled fusion are therefore the subject of research around the world.

nuclear waste
the radioactive and toxic byproducts of the nuclear-energy and nuclear-weapons industries. Nuclear waste may have an active life of several thousand years. Disposal, by burial on land or at sea, has raised problems of safety, environmental pollution and security. In absolute terms, nuclear waste cannot be safely relocated or disposed of.

nucleus
in physics, the positively charged central part of an atom, which constitutes almost all its mass. Except for hydrogen nuclei, which have only protons, nuclei are composed of both protons and neutrons. Surrounding the nucleus are electrons, which contain a negative charge equal to the protons, thus giving the atom a neutral charge.

oil
a flammable substance, usually soluble in water, and composed chiefly of carbon and hydrogen. Oils may be solids (fats and waxes) or liquids. The three main types are: essential oils, obtained from plants; fixed oils, obtained from animals and plants; and mineral oils, obtained chiefly from the refining of petroleum.

Office of Gas and Electricity Markets (OFGEM)
the United Kingdom's regulatory body that governs gas and electric utilities.

Office of Gas Safety
established under the Gas Safety Act of 1997 to monitor and promote gas safety in Victoria. It seeks to ensure the safety of gas supply and gas installations, transmission and distribution. It also controls the safety standards of gas-fitting work and maintains public and industry awareness of gas safety requirements. The department administers the gas safety standards, has oversight of the safety of the gas industry and protects consumers. Each gas company must submit a safety plan setting out safety managmenet policies and procedures.

Office of the Regulator-General
In Australia’s Victoria state, it is an independent economic regulator to promote competitive conduct and prevent the misuse of monopoly or market power, facilitate entry into the market. It is also designed to facilitate efficiency in regulated industries (including gas and electricity) and ensure that users and consumers benefit from competition and efficiency. The Regulator-General is independent of the government and of the industries it regulates, including gas and electricity.

ozone
highly reactive pale-blue gas with a penetrating odor. Ozone is an allotrope of oxygen made up of three atoms of oxygen. It is formed when the molecule of the stable form of oxygen is split by ultraviolet radiation or electrical discharge. It forms a thin layer in the upper atmosphere, which protects life on earth from ultraviolet rays, a cause of skin cancer. At lower atmosphere levels it is an air pollutant and contributes to the greenhouse effect.

particulates
from the Latin word "partire" meaning to divide, distribute or "part of." Particulates can be suspended solids or liquids that include dust from automobile and truck brake linings, road grit, ash from factory smokestacks, some from home chimneys and aerosols. Particulates reduce visibility and can cause lung and eye damage, especially when combined with other pollutants such as sulfur oxides (SOx) and nitrous oxides (NOx). Many people with respiratory problems are unaware their breathing problems can result from particulate pollution.

photovoltaic cells
used to directly convert solar radiation into electricity. Materials called semiconductors, usually made from pure silicon, transfer light energy (photons) into electrical energy in a process known as the photoelectric effect.

potential energy
the stored energy a body possesses because of its position with respect to other bodies. A stretched rubber band has potential energy. Gasoline in the liquid state has potential energy. When it is burned, it releases its chemical kinetic energy.

power
the rate at which work is done or how much work is accomplished, divided by how long it took to do the work. The unit of power is the watt (W) or joule per second. If you lift a sandwich above your head in one second, you have used about one watt of power. The word power is derived from the Latin word "posse" meaning "be able."

Public Utilities Commission
in Texas, the state regulatory agency that governs retail utility rates and practices and, in many cases, issues approvals for the construction of new generation and transmission facilities. On average, roughly 90 percent of a utility's operations are regulated by the state commission.

Public Utility Holding Company Act of 1935 (PUHCA)
act approved by the U.S. federal government that imposed restrictions on the large interstate holding companies that controlled the nation's private utilities by limiting the activities of holding companies to utility operations in defined geographic areas. This led to vertically integrated monopolies that owned the generating facilities, transmission lines, and distribution systems in an exclusive service area.

Public Utility Regulatory Policy Act of 1978 (PURPA)
act approved by the U.S. federal government in response to the energy crisis of the 1970's. It requires electric utilities to buy power from independent, non-utility generators that either use renewable energy sources or produce electricity through cogeneration as a by-product of manufacturing processes.

quad
a quadrillion BTUs (1015 BTUs). This is an enormous number equivalent to 3.6 x 106 metric tons of coal, or 172 million (1.72 x 106) barrels of oil. A quadrillion is the number 1 followed by 15 zeros. It would be impossible to count to such a number even if you counted by 1,000s for every second of your life until you were 100 years old. The United States used about 80 quads of energy in 1990.

raw material
the original material as taken from its source, usually the ground. A good example is bauxite ore, used to make aluminum.

recycle
to recycle is to put something into the cycle again; in other words, to take a product and reuse it when discarded. Recycling saves enormous amounts of energy and raw materials.

reliability
the ability to deliver uninterrupted electricity to customers on demand and to withstand sudden disturbances such as short circuits or loss of major system components. This encompasses the reliability of the generation system and of the transmission and distribution system. Reliability may be evaluated by the frequency, duration and magnitude of any adverse effects on consumer service.

renewable energy
electricity generated from sources such as solar, wind, and geothermal power rather than from fossil fuels.

resistance
in physics, that property of a substance that restricts the flow of electricity through it, associated with the conversion of electrical energy to heat; also the magnitude of this property. Resistance depends on many factors, such as the nature of the material, its temperature, dimensions, and thermal properties; degree of impurity; the nature and state of illumination of the surface; and the frequency and magnitude of the current. The SI unit of resistance is the ohm.

resource
from the Latin word "resurgere" meaning "to rise again;" a substance for which there is an identifiable use within society. Uranium was not a resource until 1939, when it was developed for use in nuclear power, medicine and weapons production.

retail customers
customers, including residences and businesses, who themselves use the electricity they purchase; also referred to as end-use customers.

Retail Electric Provider (REP)
In Texas’ competitive environment, companies will compete to sell electric service retail customers. REP's will purchase power from the generation market and resell it to the customer. The REPs will bill customers and operate their own customer service centers. All REPs must be certified by the Public Utilities Commission of Texas.

retail wheeling
a transmission or distribution service by which utilities deliver electric power sold by a third party directly to retail customers. This would allow an individual retail customer to choose an electricity supplier but still receive electricity using the power lines of the local utility.

rural electric cooperative
(also called a cooperatively owned electric utility) In the United States, a rural electric cooperative is a customer-owned utility created to transmit and distribute power in rural areas.

Rural electric cooperatives benefit from below-market financing from the Rural Utilities Service (formerly the Rural Electrification Administration), as well as low-cost power from federal hydroelectric projects. In addition, most do not pay state or federal income taxes. Typically, a board of directors sets the rates for rural electric cooperatives elected from among the cooperative's members. Today, rural electric cooperatives serve about 11 percent of U.S. electric customers.

Second Law of Thermodynamics
The Second Law of Thermodynamics states that the universe constantly tends toward a state of maximum disorder or entropy. No process involving energy transformation will spontaneously occur unless energy is degraded from an orderly, concentrated form into a disorderly, dispersed form.

securitization
a financing tool involving the sale of bonds that can lower the costs to consumers of recovering stranded costs by refinancing capital (debt and equity) with lower-cost debt.

service obligation
refers to the duties a regulated public utility must perform for its customers. Service obligation includes the duty to serve all prospective customers, to provide adequate, reliable service and to render safe, efficient and nondiscriminatory service.

shareholder-owned electric utilities U.S. public utilities owned by shareholders, organized as corporations, and regulated by Federal Energy Regulatory Commission and state public utilities commissions. About three-quarters of all Americans receive electric service from shareholder-owned electric utilities.

solar energy
energy derived from the sun's radiation. The amount of energy falling on just 0.3861 sq. mil/1 sq. km is about 4,000 megawatts, enough to heat and light a small town. In one second the sun gives off 13 million times more energy than all the electricity used in the United States in one year.

Solar heaters have industrial or domestic uses. They usually consist of a black (heat-absorbing) panel containing pipes through which air or water, heated by the sun, is circulated, either by thermal convection or by a pump. Solar energy may also be harnessed indirectly using solar cells (photovoltaic cells) made of panels of semiconductor material (usually silicon), which generate electricity when illuminated by sunlight.

Although it is difficult to generate a high output from solar energy compared to sources such as nuclear or fossil fuels, it is a major nonpolluting and renewable energy source used as far north as Scandinavia as well as in the southwest U.S. and in Mediterranean countries.

South Australian Independent Industry Regulator
established under the Independent Industry Regulator Act 1999, it regulates prices and issues licenses, monitors and enforces compliance of standards, service and supply to the regulated industries in South Australia.

stranded cost
in the Unites States, costs that were incurred by utilities to serve their customers with the understanding that state regulatory commissions would allow the costs to be recovered through electric rates.

Stranded costs can occur either because particular customers discontinue their use of a service or because such customers are no longer willing to pay the full costs incurred to provide a service. Potentially stranded costs are the result of decisions reviewed and approved by government regulators and were made by utilities under the unique regulatory compact with their state and their customers.

The Federal Energy Regulatory Commission has determined that stranded costs at the wholesale level should be paid by electric customers desiring to exit a system built to serve them.

tariff
a collection of public schedules detailing utility cost-of-service rates, rules, service territory and terms of service that a regulated utility files with its public utilities commission for official approval. Tariffs approved by a public utilities commission are binding legal documents and must be made available to the public. In effect, they constitute the contract between a utility and its customers.

telecommunications
communications over a distance, generally by electronic means. Today it is possible to communicate with most countries by telephone, or by satellite or microwave link with the capability of more than 100,000 simultaneous conversations and carrying several television channels. Integrated-Services Digital Network (ISDN) makes videophone and high-quality fax possible; the world's first large-scale center of ISDN began operating in Japan 1988. ISDN is a system that transmits voice and image data on a single transmission line by changing them into digital signals. The chief method of relaying long-distance calls on land is microwave radio transmission.

temperature
state of hotness or coldness of a body, and the condition that determines whether or not it will transfer heat to, or receive heat from, another body according to the laws of thermodynamics. It is measured in degrees Celsius (before 1948 called "centigrade"), Kelvin or Fahrenheit.

therm
a unit of energy equivalent to 100,000 BTUs; usually used as a measure of the heat energy from burning natural gas (or methane).

thermodynamics
the branch of physics dealing with the transformation of heat into and from other forms of energy. It is the basis of the study of the efficient working of engines, such as the steam and internal-combustion engines.

The three laws of thermodynamics are: 1) energy can be neither created nor destroyed, heat and mechanical work being mutually convertible; 2) it is impossible for an unaided self-acting machine to convey heat from one body to another at higher temperature; and 3) it is impossible by any procedure, no matter how idealized, to reduce any system to the absolute zero of temperature (K/-460F) in a finite number of operations.

Put into mathematical form, these laws have widespread applications in physics and chemistry.

transmission
an interconnected group of lines and associated equipment for the movement or transfer of electric energy from generation power plants to distribution substations.

Transmission and Distribution Access
The Texas Electric Choice Act provided that transmission and distribution utilities must provide open, non-discriminatory access to their facilities for all users.

turbine
n engine in which steam, water, gas or air is made to spin a rotating shaft by pushing on angled blades, like a fan. Turbines are among the most powerful machines. Steam turbines drive generators in power stations and ships' propellers; water turbines spin the generators in hydroelectric power.

unbundling
the process of separating the generation, transmission, distribution and retail functions of electric utilities into separate legal entities.

watt
a unit of power defined as a joule of energy per second; named in honor of James Watt who in 1765 constructed the first practical steam engine, originally used to power mechanical pumps to remove water from coal mines (See joules.)

wholesale customer
any entity that purchases electricity at the wholesale level, including municipal utilities, private utilities, rural electric cooperatives or government-owned utility districts. Wholesale customers purchase electricity from other wholesale suppliers to resell to their own retail customers.

wholesale wheeling
the process of sending electricity from one utility to another wholesale purchaser over the transmission lines of an intermediate utility. Under the U.S. Energy Policy Act of 1992, utilities must provide wholesale transmission wheeling services to any electric utility, federal power marketing agency, or other company generating electric energy for sale in the wholesale market.

wind turbine
windmill of advanced aerodynamic design connected to an electricity generator and used in windpower installations. Wind turbines can be either large propeller-type rotors mounted on a tall tower or flexible metal strips fixed to a vertical axle at top and bottom.

work
the physical or mechanical use of energy for accomplishing a specific task. Work is equal to force times distance, or power (energy) over time. Work as accomplished by energy is described by BTUs, watt-hours or kilowatt-hours.

TXU Energy (REP Certificate No. 10004) and Luminant are not the same company as Oncor Electric Delivery and are not regulated by the Public Utility Commission of Texas, and you do not have to buy TXU Energy's or Luminant's products to continue to receive quality regulated services from Oncor Electric Delivery.

TXU Energy (REP Certificate No. 10004) and Luminant are not the same company as Oncor Electric Delivery and are not regulated by the Public Utility Commission of Texas, and you do not have to buy TXU Energy's or Luminant's products to continue to receive quality regulated services from Oncor Electric Delivery.