The future of Britain's electricity networks - Energy and Climate Change Contents


Allowed revenue—the amount of money that a network company can earn on its regulated business.[321]

Constraints—the costs incurred through paying generators to vary their power output to prevent unacceptable post fault transmission system operating conditions.

Demand-side management—any mechanism that allows a customer's demand to be intelligently managed in response to events in the power system. Such events would include a lack of network capacity or insufficient generation.

Distributed generation—also known as embedded or dispersed generation. It is an electricity generating plant connected to a distribution network rather than the transmission network.

Distribution network operator—a DNO is a company which operates an electricity distribution network, which includes all parts of the networks from 132 kV to 230 kV in England and Wales. In Scotland 132 kV is considered to be part of transmission rather than distribution, so their operation is not included in the DNOs' activities.

Distribution Price Control Review 5—the next price control, determining the allowed revenues of distribution network operators, which runs from 1 April 2010 until 31 March 2015.

Feed-in tariffs—the price per unit of electricity that a utility or supplier has to pay for renewable electricity from private generators. These are used to encourage distributed renewable generation through private generators.

GB SQSS—the Great Britain Security and Quality of Supply Standard, which provides the basic parameters and conditions to which the transmission network is designed.

HVDC—High Voltage Direct Current (exceeding 650 V).

Interconnector—Connection between the assets of different Transmission Owners.

Licence conditions—an obligation placed on the network companies to meet certain standards of performance. The regulator has the power to take appropriate enforcement action in the case of a failure to meet these obligations.

Net present value—the valuation of future expenditures, incomes, assets etc in today's terms (for example, taking account of interest payments over a given length of time).

Price control—the control developed by the regulator to set targets and allowed revenues for network companies.

RPI-X—the form of price control currently applied to, for example, energy network monopolies. Each company is given a revenue allowance in the first year of the control period. The price control then specifies that in each subsequent year the allowance will move by 'X' per cent in real terms.

Smart grid—an electricity network that can intelligently integrate the actions of all the users connected to it—generators, consumers and those that do both—in order to efficiently deliver sustainable, economic and secure electricity supplies.

System operator—the entity responsible for operating the GB transmission system and for entering into contracts with those who want to connect to and/or use the transmission system. National Grid is the current GB system operator.

Transmission owner—a company which owns the electricity transmission network, which includes all parts of the network above 132 kV in England and Wales, and including 132 kV in Scotland.

Transmission price control review—this establishes the price control for the transmission licensees. The current price control began in April 2007 and will run until the end of March 2013.

Vertically integrated company—a company that is active in more than one level of an industry's supply chain (for example, a firm that generates electricity and also operates electricity distribution networks).

321   This Glossary includes selected terms from: Ofgem, RPI-X@20 Emerging Thinking Consultation Document Glossary of Terms, January 2010; and Electricity Networks Strategy Group, Our Electricity Transmission Network: A Vision for 2020, March 2009 Back

previous page contents next page

House of Commons home page Parliament home page House of Lords home page search page enquiries index

© Parliamentary copyright 2010
Prepared 23 February 2010