Select Committee on Science and Technology Second Report

APPENDIX 12: ACRONYMS AND GLOSSARY

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Acronyms

ACE	Association for the Conservation of Energy
Alfed	Aluminium Federation
BCA	British Cement Association
BRE	Building Research Establishment
BREEAM	Building Research Establishment Environmental Assessment Method
CBI	Confederation of British Industry
CCA	Climate Change Agreement
CCGT	Combined cycle gas turbine
CCL	Climate Change Levy
CEP	Community Energy Programme
CHP	Combined heat and power
CIGA	Cavity Insulation Guarantee Agency
CO2	Carbon dioxide
dCHP	Domestic combined heat and power
Defra	Department for the Environment, Food and Rural Affairs
DTI	Department of Trade and Industry
DTQ	Domestic Tradable Quota
DUKES	Digest of United Kingdom Energy Statistics
EAPG	Energy Advice Providers Group
ECA	Enhanced Capital Allowances
ECI	Environmental Change Institute
EEC	Energy Efficiency Commitment
EIC	Environmental Industries Commission
EPBD	Energy Performance of Buildings Directive
EPSRC	Engineering and Physical Sciences Research Council
ESCO	Energy Service Company
ESRC	Economic and Social Research Council
EST	Energy Saving Trust
ETS	Emissions Trading Scheme
GW	Gigawatt (1,000,000,000 watts)—see below
GWh	Gigawatt hour
HBF	House Builders Federation
IEA	International Energy Agency
IPCC	Intergovernmental Panel on Climate Change
Ktoe	Kilotonnes (1,000 tonnes) oil equivalent
kW	Kilowatt (1,000 watts)—see below
kWh	Kilowatt hour
LGA	Local Government Association
MMC	Modern Methods of Construction
MtC	Megatonnes carbon
Mtoe	Megatonnes (1,000,000 tonnes) oil equivalent
MTP	Market Transformation Programme
MW	Megawatt (1,000,000 watts)—see below
MWh	Megawatt hour
NAP	National Allocation Plan
NERC	Natural Environment Research Council
NETA	New Electricity Trading Arrangements
NIA	National Insulation Association
ODPM	Office of the Deputy Prime Minister
Ofgem	Office of Gas and Electricity Markets
PIU	Performance and innovation unit
POST	Parliamentary Office of Science and Technology
R&D	Research and Development
RCEP	Royal Commission on Environmental Pollution
RCUK	Research Councils UK
RSPB	Royal Society for the Protection of Birds
SEPN	Sustainable Energy Policy Network
tC	tonnes carbon
TW	Terawatt (1,000,000,000,000 watts)—see below
TWh	Terawatt hour
UKERC	United Kingdom Energy Research Centre
U-value	Measure of the amount of heat transferred through one square metre of a given material, given a temperature differential of one degree Kelvin, expressed in watts per square metre per degree difference (W/m2K)

Glossary

Units of energy

Various units are used to quantify energy. For example, the Digest of UK Energy Statistics uses tonnes oil equivalent (toe). In this report energy is quantified in terms of watt-hours (Wh) and, in the case of Dr Sinclair's paper, joules (J).

A joule is a measure of total energy used, equal to the work done when a force of one newton acts through a distance of one metre.

A watt is a measure of the rate of use, or generation, of energy (not just electricity), equal to one joule per second. If follows that a watt-hour is a measure of the total amount of energy used, or generated, over time—one watt-hour being equal to 3,600 joules, one kWh equal to 3.6 MJ. A 100 W light bulb left on for two hours will consume 200 Wh of energy, or 720,000 joules (0.72 MJ).

One tonne of oil equivalent, equivalent to 7.4 barrels of crude oil in primary energy, is approximately equal to 42 GJ (42 billion joules), or 11.7 MWh.

The abbreviations k, M, G or T preceding Wh or J indicate increasing amounts:

• k (kilo): thousands (1,000 or 10³)
• M (mega): millions (1,000,000 or 10⁶)
• G (giga): billions (1,000,000,000 or 10⁹)
• T (tera): million-millions (1,000,000,000,000 or 10¹²)
• P (peta): thousand-million-millions (1,000,000,000,000,000 or 10¹⁵)

Carbon units and emissions

Emissions to the atmosphere of greenhouse gases are by convention quoted in terms of the carbon (C) equivalent amount, as carbon dioxide (CO₂) is the principal greenhouse gas occurring as a by-product of burning fossil fuels. Amounts are often described in millions of tonnes (Mt) of carbon, MtC. Occasionally, however, emissions are expressed in terms of CO₂ equivalence (for instance, in Dr Sinclair's appendix to this report). The relative atomic weight of the carbon and oxygen atoms contained in each molecule of CO₂ (12:32) means that 1 tonne of CO₂ is equivalent to 0.273 tonnes carbon.

When calculating emissions amounts of other greenhouse gases are multiplied by a factor, called the Global Warming Potential (GWP), that approximates their time-integrated warming effect in the atmosphere, relative to CO₂. Considering a time horizon of 100 years (the period used when calculating national greenhouse gas inventories), methane (CH₄) has a GWP of about 24 times that of CO₂, nitrous oxide (N₂O) has a GWP of some 320.

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