An option which gives the user the right to buy a commodity at a given price in the future.

Callable bond
A bond which the issuer has the right to redeem prior to maturity by paying a specified call price.

Calorific Value (CV)
Amount of heat given by the specified quantity of gas. This is used to calculate the energy consumed based on the volume of gas used. It is measured in joules per kilogram.

A swap transaction in which the buyer seeks a maximum price level for supplies.

Cap and Trade Scheme
A scheme, e.g. covering CO2 or green house gas emissions, in which the quantity of pollutant is fixed and participants trade emission allowances to meet the cap at lowest cost.

Capacity (1)
The load for which a generating unit, generating station or other electrical apparatus is rated either by the user or manufacturer.

Capacity (2)
See Maximum Available Capacity

Capacity (3)
The amount of gas which can be held within or transported through the pipeline and storage facilities.

Capacity Charge
See Availability Charge

Capacity Deliverability
The daily rate at which energy can be withdrawn from a storage facility.

Capacity Entry
The amount of capacity a Shipper is entitled to put into the system at a particular input terminal on a day.

Capacity Exit
The amount of gas a Shipper is entitled to withdraw from a pipeline system in order to meet the requirements of its customers on any day.

Capacity Margin Instruments (CMI)
A mechanism such as a capacity obligation that requires electricity industry participants to provide a defined level of generating capacity.

Carbon Capture / Storage (CCS)
Carbon capture: A credit or permit arising from a greenhouse gas emissions reduction scheme, such as emissions trading, JI or CDM. Emissions are controlled by setting a cap on total emissions and allowing the market sector(s) to reach an economically balanced response via trading of emissions allowances. Carbon storage: Sometimes called carbon sequestration, this is the long-term storage of carbon or CO2 in the forests, soil, ocean, or underground in depleted oil and gas reservoirs, coal seams and saline aquifers. Carbon Capture and Storage can be referred to as CCS.

Carbon Credits
A credit or permit arising from a greenhouse gas emissions reduction scheme, such as emissions trading, JI or CDM. Emissions are controlled by setting a cap on total emissions and allowing the market sector(s) to reach an economically balanced response via trading of emissions allowances.

Carbon Dioxide
An inert non-toxic gas produced from decaying materials, respiration of plant and animal life, and combustion of organic matter, including fossil fuels.

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

Carbon Dioxide Equivalent (CO2e)
There are six main greenhouse gases that cause climate change and are limited by the Kyoto protocol. Each gas has a different global warming potential. For simplicity of reporting, the mass of each gas emitted is commonly translated into a carbon dioxide equivalent (CO2e) amount so that the total impact from all sources can be summed to one figure.

Carbon Dioxide Tonnage
In relation to carbon emissions, CO2 is measured in tonnes. A typical household has around 10.9 tonnes of CO2 emissions per year.

Carbon Footprint
A measure of the amount of carbon dioxide or CO2 emitted through the combustion of fossil fuels; can be measured on a personal or national level, or according to a specific activity, such as taking a flight to go on holiday.

Carbon Intensity
The amount of CO2 emitted for a given volume of electricity. It allows the emissions from different amounts of electricity to be compared. For example, a coal power station produces around 890 grams of CO2 for every kilowatt hour of electricity, whereas a gas-fired power station produces around 370 grams of CO2 for each kilowatt hour of electricity.

Carbon monoxide (CO)
A colourless, odourless, poisonous gas formed when carbon compounds burn in insufficient oxygen.

Carbon Neutral
An activity or process that doesn't add to the net amount of CO2 in the atmosphere. As the organisation or product will typically have caused some greenhouse gas emissions, it is usually necessary to use carbon offsets to achieve neutrality.

Carbon Offset
A carbon offset negates the overall amount of carbon released into the atmosphere by avoiding the release or removing it elsewhere e.g. through a renewable energy or energy conservation project. Voluntary carbon offsetting schemes can help people reduce their carbon footprint, but should only be used as a last resort. It is also important that a credible scheme is used.

Carbon Reduction Commitment (CRC)
The CRC is a UK government emissions trading scheme for large organisations that are not eligible for EU Emissions Trading. This includes banks, large offices, universities, large hospitals, large local authorities and central government departments. The scheme is mandatory. The CRC is expected to deliver emissions reductions totalling 0.5m tonnes of carbon (Mtc) per year by 2015.

Carbon Tax
A tax levied on fossil fuel usage usually based on the carbon content generally designed to curb use rather than just raise revenue.

Carbon Trading
The trading of personal, corporate or national credits to maintain and gradually reduce carbon emissions. Companies, nations or individuals who beat the targets can sell the balance as credits to those that exceed their limits.

Carbon Trust
An independent non-profit company set up by the UK Government with support from businesses to encourage and promote the development of low carbon technologies. Key to this aim is its support for businesses in reducing carbon emissions through funding, supporting technological innovation and by encouraging more efficient working practices.

Carbon Value
In order to encourage individuals to reduce carbon dioxide emissions a value has been placed on carbon. The more you produce the more you pay. Within the EU, the Emissions Trading Scheme provides a mechanism for capping total CO2 emissions and generates a carbon value, as market participants and given are given allocation of CO2 they are permitted to produce, and can buy from or sell to each other to balance their allocations with their requirements. To give investors the confidence to invest in low carbon solutions and thereby help to reduce emissions it is necessary to have certainty that there will be a long-term value of carbon.

Cash Commodity
The actual, physical commodity.

Cash Market
The market for a cash commodity where the actual, physical product is traded.

Change of Managing Agent (CoMA)
A change of managing agent responsible for managing a property whether or not the consumer of energy, owner or tenant also changes.

Change of Measurement Class (CoMC)
'Measurement class' indicates the method used to read electricity meters on site - the change is always from half-hourly to non-half-hourly metering or vice-versa.

Change of Ownership (CoOwner)
A change of ownership of premises whether or not the owner is responsible for paying for the energy used.

Change of Profile Class (CoPC)
'Profile class' is an indication of the type of consumer and billing frequency - changes can be from and to 'domestic', business', 'quarterly' and 'monthly'.

Change of Tenancy (CoT)
A change of consumer in tenanted premises where the tenant is responsible for paying for the energy used.

Allows a meter to poll different measurement quantity IDs (LAG LEAD etc).

Cost, insurance and freight, the price of coal delivered to a port.

A joined up series of electrical conductors, wires and components that allow an electrical current to flow.

Circuit breaker
A device that protects a circuit from power surges by stopping the power flowing.

Clean Coal Technologies (CCTs)
There are significantly higher greenhouse gas emissions for each unit of electricity produced by coal-fired generation than there are for alternative methods of generation. CCT makes using coal as a power source more environmentally friendly.

Clean Development Mechanism (CDM)
One of the three market mechanisms established by the Kyoto Protocol. The CDM is designed to promote sustainable development in developing countries and assist Annex I Parties in meeting their greenhouse gas emission reduction commitments. It enables industrialized countries to invest in emission reduction projects in developing countries and to receive credits for reductions achieved.

A financial intermediary matching every buyer and seller in a market, the primary role of a formal futures exchange.

Climate Change
The variation in the Earths global climate over time. Man-made climate change is a variation directly attributable to human behaviour.

Climate Change Agreement
An agreement between the government and a business user, whereby a reduced rate of Climate Change Levy is payable in return for a commitment by the user to achieve certain pre-determined targets for energy usage or carbon emissions.

Closing Out (Offset)
Liquidating an existing long or short futures or option position with an equal and opposite transaction, also known as Offset.

Coal Bed Methane
Natural gas generated and trapped in coal seams. Coal Bed Methane (CBM) involves directly drilling into unworked coal and coal measures strata to release the methane locked within it rather than utilising methane released as a result of mining activities.

Coal Generation
Coal is ground to fine powder and then burned in huge boilers to heat water. The steam produced passes through a turbine, making it rotate and generating electricity that is then fed into the national grid.

Coal Mine Methane
Methane continues to emit from the coal mine after closure, and recently the concept of collecting the gas from abandoned mines to provide an energy source that would otherwise be wasted has been developed.

Also know as Combined Heat and Power

Sector Skills Council for the oil and gas extraction and chemical manufacturing sector.

A swap transaction in which a price range between a floor and ceiling price is hedged instead of a single fixed price, allows the user the benefit of a limited amount of market fluctuation.

Combined Cooling Heat and Power (CCHP)
A system in which fuel is used to simultaneously produce electrical (or mechanical) power plus recovering useful thermal energy for use in cooling & heating.

Combined cycle gas turbine (CCGT)
A power plant combining 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 which are fed to a boiler, where steam is raised to drive a conventional steam turbine also connected to the generator.

Combined Half Hourly (HH) Data Charge
Costs associated with collecting and handling metering data from half hourly (HH) read meters.

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) which can be used for industrial, commercial, heating, or cooling purposes.

Combined Heat and Power Quality Assurance (CHPQA)
CHPQA provides the means to assess and monitor Good Quality CHP Capacity.

Commitment (Open interest)
The number of futures contracts in existence at any time which have not been satisfied by offsetting sale or purchase, or by actual contract delivery.

Commodity Charge
A fee levied by the Grid Operator on the quantity of gas transported through the system.

Communication Fees
Fees paid by half-hourly metered customers to the company which collects their consumption data via a phone line of pak net radio - normally collected by the supplier.

Communications Line (Coms. Line)
The telephone communications line installed with half-hourly metering to enable meters to be read remotely. A charge is normally levied by the Meter Operator (MOp) to cover the installation and maintenance costs.

Competition Clause
A clause which may by mutual agreement be included in an energy supply contract of (normally) longer than one year's duration enabling the consumer to move to a new supplier at the end of a specified period if an improved price can be negotiated, the incumbent supplier may seek to retain the contract by matching or improving upon the new supplier's offer.

A substance that allows an electric current to pass through it easily.

Connection Agreement
A document that states the Agreed Capacity for a property with the Network Operator.

The individual or company using the energy at a supply point whether or not that person or company is the owner of the property.

Consumer Hedge
The hedging of purchases intended to lock in a set price by a user.

The maximum demand multiplied by a given period of time expressed in kWh

A market situation in which prices in succeeding delivery months are progressively higher than in the nearest delivery month, the opposite of 'Backwardation'.

Contango Market
A market situation in which prices are progressively higher in the succeeding delivery months than in the nearest delivery month.

An agreement made between the customer and shipper defining the rules of the trading relationship. 1. Firm - the customer agrees to take a pre-determined quantity of gas at a pre-determined price negotiated as part of the contractual agreement (used by the Commercial Gas Business). 2. Tariff - the customer buys gas at a standard rate and is billed according to the consumption indicated on the meter (used by Residential Business).

Contract for Differences (CfD)
A financial arrangement used in swaps and other financial dealings in which the arithmetic difference between two similar but opposite transactions is exchanged rather than the total amounts involved.

Contract Price
The price, normally expressed in pence (or cents) per therm or kW which the energy consumer agrees to pay to the energy supplier for the duration of an energy supply contract. Contract prices can be 'floating', tied to spot market assessments published by market pricing services as opposed to set at an outright level.

Contract Price Structure
This indicates a supply offer, which has all delivery charges (DUoS & TUoS) built into the unit rates for the supply of electricity.

Conventional thermal power station
A power station which generates electricity by burning fossil fuel to produce heat to convert water into steam, which then powers steam turbine.

CoP3 - Code of Practice 3 
Classification for those customers with electricity demand greater than 1 MW with two meters installed (main and check). These supply three feeds of data (kW, lag, lead).

CoP5 - Code of Practice 5
Classification for those customers with electricity demand between 100 kW and 1 MW.

Corporate Social Responsibility (CSR)
CSR is aimed to embrace responsibility for the company's actions and encourage a positive impact through its activities on the environment, consumers, employees, communities, stakeholders and all other members of the public sphere.

Corrector Meter
For sites using large amounts of gas it is often deemed necessary to measure the temperature and pressure variations more accurately rather than just applying a fixed conversion factor. In these cases an additional corrector meter is attached to the meter.

Cost To Serve
These are the costs that are incurred as an electricity supplier. These include the costs of maintaining IT systems, paying staff to manage customer accounts.

Counterparty risk
The risk that the organisation with which you are undertaking a contractual position will fail to fulfil its obligations, usually by failing to pay or failing to deliver commodities or securities.

To close out a short futures or options position.

Crack Spread
The simultaneous purchase or sale of crude against the sale or purchase of refined petroleum products. These spread differentials which represent refining margins are normally quoted in dollars per barrel by converting the product prices into dollars per barrel and subtracting the crude price.

CT - Current Transformer
Current Transformers are meter types that allow large loads to be measured by reducing the level of current passing through the meter to a manageable level.  An example CT Ratio is 200/5 that means that for every 200 amps of current received, only 5 amps are passed through the meter. As a result CT meters rarely require a site shut down when being installed.

CT Metering
Metering that is 100 amp and above.

Curve (Forward)
A forward view of the value of the future contracts as at a particular date, not an expectation of what prices will be. A forward view of the value of the future contracts as at a particular date, not an expectation of what prices will be.

Customer reads
Meter readings taken by the consumer and passed to the supplier to avoid supply invoices based on estimations.