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Generation of electricity by companies for their own use, whose main business is not electricity generation.

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Baseload Capacity

The power output that generating equipment could continuously produce.

Baseload Demand
The minimum demand experienced by an electric utility, usually around 30 ~ 40% of the peak demand.

Baseload Plant
The generating plant normally operated to meet requirement for energy on a round-the-clock basis.

British Electricity Trading and Transmission Agreement (BETTA)
This agreement will see the introduction of a GB wide electricity market in April 2005 and will replace the separate Scottish and England & Wales markets. It has two key aims; firstly to bring more competitive prices to consumers and secondly to support the growth of renewables (particularly in Scotland).

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Carbon Cycle

The process of removal and uptake of carbon on a global scale. This involves components in food chains, in the atmosphere as carbon dioxide, in the hydrosphere and in the geosphere. The major movement of carbon results from photosynthesis and from respiration.

Carbon dioxide (CO2)
A colourless, odourless, incombustible gas present in the atmosphere and formed during the decomposition of organic compounds e.g. burning of fossil fuels.

Carbon monoxide (CO)
A colourless and poisonous gas, produced by incomplete burning of carbon-based fuels. including gasoline, oil, and wood. Carbon monoxide is also produced from incomplete combustion of many natural and synthetic products.

Carbon Sink
A pool (reservoir) that absorbs or takes up released carbon from another part of the carbon cycle. For example, if the net exchange between the biosphere and the atmosphere is toward the atmosphere, the biosphere is the source, and the atmosphere is the sink.

The sudden formation and collapse of low-pressure bubbles in liquids by means of mechanical forces, such as those resulting from rotation of a marine propeller.

Chlorofluorocarbons (CFCs)
A synthetically produced compounds containing varying amounts of chlorine, fluorine and carbon. Used in industrial processes, refrigeration and as a propellant for gases and sprays. In the atmosphere they are responsible for the depletion of ozone and can destroy as many as 10,000 molecules of ozone in their long lifetime. Their use is now currently restricted under the Montreal Protocol.

Climate Change
The long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate which is attributed directly or indirectly to human activity.

Climate Change Levy
UK tax on energy consumption.

A natural dark brown to black graphite like material used as a fuel, formed from fossilized plants and consisting of amorphous carbon with various organic and some inorganic compounds.

Combined Cycle Gas Turbine Plant
Power plant which combines gas and steam turbines in the same operation. The gas turbine produces mechanical power to drive the generator and heat in the form of hot exhaust gases that are fed to a boiler, where steam is raised to drive a conventional steam turbine also connected to the generator. Uses gas as the primary fuel with heat recovered from the turbine exhaust utilised in a steam turbine.

Combined Heat and Power
Simultaneous generation of usable heat and electrical power in a single process. A generating facility that produces electricity and another form of useful thermal energy (such as heat or steam) used for industrial, commercial, heating, or cooling purposes. An installation for the on-site generation of useful heat and power.

Computational Fluid Dynamics (CFD)
CFD is the broad topic encompassing the numerical solution, by computational methods, of the governing equations which describe fluid flow, the set of the Navier-Stokes equations, continuity and any additional conservation equations, for example energy or species concentrations.

Conventional Thermal Power Station
Power station generating electricity by burning fossil fuel to produce heat to convert water into steam, which then powers steam turbine.

Conventional Thermal Power Station
Power station generating electricity by burning fossil fuel to produce heat to convert water into steam, which then powers steam turbine.

A natural dark brown to black graphite like material used as a fuel, formed from fossilized plants and consisting of amorphous carbon with various organic and some inorganic compounds.

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Declared Net Capacity

The maximum power available from generating station on a continuous basis less any power from the network used to run the station.

The country's requirement for power.

Demand-Side Management
The planning, implementation, and monitoring of activities designed to encourage consumers to modify patterns of electricity usage, including the timing and level of electricity demand.

The mass per unit volume (kg/m3) of a substance under specified conditions of pressure and temperature.

Department of the Environment, Transport and the Regions

Distributed Generation
Generation by plant connected to a distribution system rather than to a transmission system.

Distribution System
The local wires, transformers, substations and other equipment used to distribute and deliver energy to end-use consumers.

Department of Trade and Industry

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Electric and Magnetic Fields (EMF’s)

Fields created by the presence or flow of electricity in an electric conductor or electricity consuming appliance or motor. Electric and magnetic fields, set up around electrical conductors due to the passage of electricity through that conductor.

A measure of the amount of 'work' that can be done by, or is needed to operate, an energy conversion system, sometimes measured in 'joules' (J) or 'kilowatt hours' (kWh).

Embedded generation

Emissions Trading
A system that would allow countries that have committed to targets to "buy" or "sell" emissions permits among themselves as detailed by the Kyoto Protocol. It provides participating parties with the opportunity to reduce emissions where it is most cost-effective to do so.

Environmental Impact Assessment (EIA)
A process for identifying the potential impacts of development and communication of these to the competent authority prior to decision being made on development.

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A collection of marine current turbines.

Flue Gas Desulphurisation
A process for removing Sulphur Dioxide from power stations’ flue gases.

Fossil Fuel
A collective term for coal, petroleum and natural gas, which are used for energy production through combustion. They are called fossil fuels because they are made of fossilized, carbon-rich plant and animal remains. These remains were buried in sediments millions of years ago and, over geological time, have been converted to their current state. Fossil fuels can be extracted from the sediments by humans millions of years after their deposition and their stored energy can be used as fuel when it is burned.

An accumulation of marine organism deposits on a submerged metal surface. The accumulation of undesirable foreign matter

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Gigawatt (GW)

A unit of power equal to 1 billion watts; 1 million kilowatts, or 1,000 megawatts.

Gigawatt-hour (GWhr)
A unit of energy equal to million kilowatt-hours. 1 GWhr is equivalent to the total electricity typically used by 250 homes in one year. Equal to 1000 megawatt-hours.

Global Warming
Strictly speaking, the natural warming and cooling trends that the Earth has experienced all through its history. However, the term global warming has become popularized as the term that encompasses all aspects of the global warming problem, including the potential climate changes that will be brought about by an increase in global temperatures.

Global Warming Potential (GWP)
The concept has been developed to compare the ability of each greenhouse gas to trap heat in the atmosphere relative to another gas.

Greenhouse Effect
Warming of the atmosphere due to the reduction in outgoing solar radiation caused by greenhouse gases.

Greenhouse Gases (GHGs)
Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and hydrofluorocarbons (HFCs). These gases absorb the earth's radiation and warm the atmosphere. Some greenhouse gases occur naturally but are also produced by human activities, particularly the burning of fossil fuels. When greenhouse gases build up in the atmosphere, they have an impact on climate and weather patterns. They are usually measured in carbon dioxide equivalents.

Grid Supply Point
A point of supply from the national transmission system to the local system of the distribution network operator.

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Hydro-Electric Power Plant

A plant that uses natural water flows to turn turbines.

Hydro-Electric Pumped Storage
A plant generating electricity during peak loads by using water previously pumped into an elevated storage reservoir during off-peak periods when excess generating capacity is available to do so.

Hydroflurocarbon (HFC)
A compound consisting of hydrogen, fluorine, and carbon which are used as a replacement for CFCs. Because they do not contain chlorine or bromine, they do not deplete the ozone layer and have an ODP of 0. Some HFCs have a high GWP.

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Installed Capacity

The total capacity of generation units installed at a power station.

A connection or link between power systems that enables them to draw on each other's reserve capacity in time of need.

Intergovernmental Panel on Climate Change (IPCC)
Established in 1988 by the World Meteorological Organization and the United Nations Environment Program (UNEP), the IPCC is the authoritative international body charged with studying climate change. The IPCC surveys the worldwide technical and scientific literature on climate change and publishes assessment reports. Its widely quoted 1995 report found that "the balance of evidence suggests that there is a discernible human influence on global climate."

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Joint Implementation (JI)

The concept that, through the Framework Convention on Climate Change, a developed country is involved in emissions projects projects that result in a real, measurable and long-term reduction in net greenhouse gas emissions in a developing country. In its pilot phase, launched at the first COP in 1995, JI is called Activities Implemented Jointly (AIJ). The developed country cannot earn emissions credits during this pilot phase, which ends in 1999.

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Kilowatt (kW)

A standard unit of electrical power equal to 1000 watts, or to the energy consumption at a rate of 1000 joules per second.

Kilowatt-hour (kWhr)
A unit of energy. A typical home uses around 3,300 kWh of electricity per year.

Kinetic Energy
The energy possessed by a body because of its motion, equal to one half the mass of the body times the square of its speed.

A unit of speed equivalent to one nautical mile per hour or approximately 1.85 kilometres per hour.

Kyoto Protocol
Legally binding agreement between developed countries to reduce emissions of six greenhouse gases to tackle the threat of climate change. International agreemnt governing the reduction in greenhouse gases.

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Load (Electric)

The amount of electric power delivered or required at any specific point or points on an electric system. The requirement originates at the energy-consuming equipment of the consumer.

Load Factor
The ratio of the actual energy output of a generating plant to the maximum possible energy output over a time period.

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Mechanical Energy

Energy stored in a mechanical form.

Megatonne of Carbon (MtC)
One million tonnes of Carbon. Emissions of carbon dioxide are often expressed in terms of their carbon content. 1 MtC is equivalent to 3.67 million tonnes of carbon dioxide.

Megawatt (MW)
Standard measure of generating plant capacity equal to one thousand kilowatts, or one million watts. Medium to large power stations have capacity typically in the range of 500 MW to 2,000 MW.

Megawatt Hour (MWhr)
A unit of energy. Used to measure usable or "active" power. Equal to 1000 kilowatt-hours.

Methane (CH4)
A hydrocarbon with four Hydrogen atoms attached to each Carbon atom. It is colourless, and flammable and is the main constituent of natural gas. Identified as one of the three major greenhouse gases responsible for climate change. Although there is less methane than carbon dioxide in the atmosphere, methane is a more effective heat-trapping greenhouse gas with an estimated global warming potential of 21 times that of carbon dioxide.

The term used to cover measures that seek to avoid, reduce or delay global warming by reducing those emissions of atmospheric gases that are of human origin or within human control

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Natural Gas

A mixture of hydrocarbon gases that occurs with petroleum deposits. Principally methane together with varying quantities of ethane, propane, butane and other gases. Used as a fuel and in the manufacture of organic compounds.

New Electricity Trading Arrangements.

New Renewables Obligation (NRO)
Part of a range of measures comprising the UK Government Climate Change Programme.

Nitrogen Oxides (NOx)
Oxides of nitrogen, which can contribute to acid rain formation. Also leads to poor air quality. Formed in the combustion process when nitrogen in the air or fuel combines with oxygen.

Non Fossil Fuel Obligation (NFFO)
Orders requiring the Regional Electricity Operators in England and Wales and Northern Ireland to secure specified amounts of electricity from renewable resources.

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Ozone (O3)

A colourless gas containing three atoms of Oxygen.

Ozone Depleting Potential (ODP) A number that refers to the amount of ozone depletion caused by a substance. It is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of CFC-11.

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Peak demand

The highest level of demand recorded on the transmission system.

The changing of the natural environment either by natural or artificial means so that it becomes harmful to living things, most often referring to the discharge of toxic chemicals/materials from manufacturing or power generation.

The rate at which energy is produced or consumed.

Primary Electricity
Electricity obtained from nuclear, hydro and non-thermal renewables, i.e. not from fossil fuels.

Primary Fuels
Fuels obtained from natural sources directly, for example coal, oil and natural gas.

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Rated Velocity

The rated velocity of each scheme (the current velocity at which the power train produces its rated output) has been optimised by minimising the unit cost of energy as calculated by the MCT spreadsheet using the MCT site characteristics.

Registered Capacity
Full load capability of a generating unit as declared by the generator, less the energy consumed through the unit transformer.

Renewable Energy
Energy derived from resources that are regenerative. This includes solar power, wind, wave and tide and hydroelectricity. Wood, straw and waste are often called solid renewable energy, while landfill gas and sewage gas can be described as gaseous renewable.

Renewable Obligation (Scotland)

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Secondary fuels

Fuels obtained from primary sources for example, electricity generated from burning coal, gas or oil.

Sinks Natural systems such as forests and wetlands that absorb and store greenhouse gases

Site of Specific Scientific Interest (SSSI)
The main nature conservation areas designation in Great Britain. These sites are special for their plants, animals, habitats and landforms or a combination of the above.

Sulphur Dioxide (SO2)
A gas produced by the combustion of sulphur-containing fuels such as oil and coal. Contributes to acid rain and can affect air quality.

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Terawatt Hour (TWhr)

A unit of energy equal to one million kilowatt-hours. Approximately equivalent to the total electricity used by 250,000 homes in one year. Equal to 1000 gigawatt-hours.

Tidal Power
The power available from the rise and fall of ocean tides. A tidal power plant works on the principal of a dam or barrage that captures water in a basin at the peak of a tidal flow, then directs the water through a hydroelectric turbine as the tide ebbs.

Tidal Stream Energy

Any of various machines in which the kinetic energy of a moving fluid is converted to mechanical power by the impulse or reaction of the fluid with a series blades arrayed about the circumference of a wheel or cylinder.

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A vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.

A unit of electrical force equal to that amount of electromotive force that will cause a steady current of one ampere to flow through a resistance of one ohm

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Watt (W)

The conventional unit that measures the rate of flow of energy. One watt amounts to one joule per second.

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