Calorific Value (CV)


Definition: A measure of the energy released as heat when a fuel is burned.




Definition: The rated load-carrying capability of electrical equipment such as generators of transmission lines, typically expressed in megawatts or megavolt amperes. For gas, the rated transportation volume of natural gas pipelines, typically expressed in millions of cubic feet per day.


Capacity Charge


Definition: An element in a two-part pricing method used in capacity transactions (energy charge is the other element). The capacity charge, sometimes called Demand Charge, is assessed on the amount of capacity being purchased.


Carbon Credit


Definition: A tradable financial instrument, normally representing one tonne of carbon equivalent. Carbon credits can be used by organizations to offset their carbon emissions, subject to certain criteria and depending upon which scheme they relate to. This allows for organizations to invest in large-scale carbon reduction projects and thus demonstrate carbon abatement activity in the form of carbon savings.


Carbon Dioxide (CO2)


Definition: A naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. Carbon dioxide is a greenhouse gas, warming the Earth's surface to a higher temperature by reducing outward radiation from being released.


Carbon Footprint


Definition: A measure of the total greenhouse gas emissions caused directly and indirectly by an organization. It can also be assessed for a particular event, product, or individual. It is expressed as carbon dioxide equivalent.


Carbon Offsetting


Definition: Use of carbon credits by an organization to buy in greenhouse gas emission savings produced externally to demonstrate emissions savings.


Carbon Reduction Commitment (CRC)


Definition: An innovative climate change and energy saving scheme for the UK that encourages improvements in energy efficiency, saving organizations money.


Carbon Reduction Commitment (CRC)


Definition: The prices charged to market participants who are imbalanced at the end of the day by the System Operator (SO). They reflect the costs incurred by the SO in addressing this imbalance.


Certified Emission Reduction (CER)


Definition: Commonly referred to as carbon credit, equivalent to one tonne of CO2 reduction, which are issued under Clean Development Mechanism (CDM) projects.




Definition: A market participant who uses technical analysis to chart the price patterns of commodities to make buy and sell decisions based on this analysis.




Definition: A market that is highly volatile.


Clean Dark Spread


Definition: The profit realized by a power generator after paying for the cost of coal fuel and carbon allowances.


Clean Development Mechanism (CDM)


Definition: One of the mechanisms established under the 1997 Kyoto Protocol for countries to meet their greenhouse gas emission targets. CDM allows for collaborative projects between countries in order to reduce emissions or sequester carbon in developing countries.


Clean Spread


Definition: The generating margin for gas- and coal-fired electricity plants after the cost of EU Emissions Trading Scheme (EU ETS) carbon allowances has been removed.




Definition: A mechanism by which transactions are settled through an organization that assures settlement.


Climate Change Levy (CCL)


Definition: A levy on the taxable supply of specified energy products (taxable commodities) for use as fuels that are for lighting, heating, and power by business consumers including consumers in industry, commerce, agriculture, public administration, and other services. CCL does not apply to taxable commodities supplied for use by domestic consumers or to charities for non-business use.




Definition: Burning natural gas and another fuel type in order to decrease the amount of air pollutants and/or use the most competitively priced fuels available.


Combined Cycle Gas Turbine (CCGT)


Definition: The preferred technology used in gas-fired power generation.


Combined Heat and Power (CHP)


Definition: Integrated production of usable heat and power (electricity), in one single, highly efficient process. CHP generates electricity while also capturing the usable heat that is produced in this process.


Combustion Turbine


Definition: A rotary engine that extracts energy from a flow of combustion gas.


Commodity Future


Definition: A futures contract on a commodity. Unlike financial futures, the prices of commodity futures are determined by supply and demand as well as the cost-of-carry of the underlying. Commodity futures can, therefore, either be in contango (where futures prices are higher than spot prices) or backwardation (where futures are lower than spot).


Comp (Comps)


Something of value (service or product) - such as a meal/hotel room(s) given free of charge.  Disclaimer: This can have two meanings; either a promotion or deal (comp) or because of the poor standards in the level of service or experience (comped) 


Competitive Transition Charge


Definition: A non-bypassable charge levied on each customer of a distribution utility, including those who are served under contracts with non-utility suppliers, for recovery of a utility's transition costs.Compressor Station


Definition: Station used to recompress gas that has lost pressure due to long-distance transmission to the required pressure.




Definition: A condition that occurs when insufficient transfer capacity is available to implement all of the preferred schedules for electricity transmission simultaneously.




Definition: Term used to describe an energy market in which the anticipated value of the forward price is higher than the current spot price. When a market is in Contango, market participants expect the spot price to go up. The reverse situation is described as Backwardation.


Counterparty Risk


Definition: The risk that a counterpart to a transaction or contract will default on its obligation under the contract.


Crack Spread


Definition: A type of commodity product spread involving the purchase of crude oil futures and the sale of gasoline and heating oil futures.


Credit Risk


Definition: The risk that a financial loss will be incurred if a counterparty to a derivatives transaction does not fulfill its financial obligations in a timely manner.




Definition: Refers to the futures market and includes everything beyond the current month going forwards.


Customer Choice


Definition: Allowing all customers to purchase kilowatt-hours of electricity from any of a number of companies that compete with each other.