| EA | The Environment Agency; The regulator for the environment, including rivers and waste disposal |
| [EA] | Electricity Association; a trade association representing the ESI, which was disbanded in September 2003, its primary activities having been transferred to the AEP, and the new ENA and ERA |
| EEC | Energy Efficiency Commitment whereby companies can be rewarded for obtaining agreed improvements in energy efficiency |
| EfW | Energy from waste |
| EI | The Energy Institute |
| Elexon | The company that administers the Balancing and Settlement Code |
| Embedded generation | See distributed generation |
| Embedded benefits | Commercial benefits arising from generation connected to distribution networks, e.g. the avoidance of BSUoS, TNUoS, BSC charges, transmission losses and Residual Cashflow Reallocation |
| ENA | Electricity Networks Association; trade association representing electricity and gas transmission and distribution network operators, formed following the disbanding of the EA |
| EPBD | Energy Performance of Buildings Directive |
| EPSRC | The Engineering and Physical Sciences Research Council |
| Energy efficiency | The amount of useful output achieved for each unit of input energy. Energy efficiency can be improved by reducing wastage both in the equipment and its use |
| Energy mix | The distribution of different energy sources within the total supply |
| ERA | Electricity Retail Association; trade association representing suppliers formed following the disbanding of the EA |
| ERD | European Renewables Directive |
| ESQCR | Electricity Safety Quality and Continuity Regulations 2002; The statutory instrument in relation to the distribution of electricity |
| ESI | Electricity Supply Industry |
| EST | The Energy Savings Trust; a Government organisation to promote energy efficiency to domestic, business, local government and trade sectors |
| ETG | The Emissions Trading Group; a body advising the UK Government on the implementation of the EU ETS, and its inter-relationships with UK ETS, CCAs and other measures |
| ETSU | The Energy Technology Support Unit formerly of the DTI, now the privatised Future Energy Solutions |
| EU ETS | The Emissions Trading Scheme of the European Union, due to be introduced in the UK in about 2005 |
| Externalities | The external impacts associated with power generation, but not traditionally costed into the energy price |
| G(number) | Engineering recommendation documents, published by ENA |
| Generation | The energy output of a generating plant over a period of time |
| GEMA | Gas and Electricity Markets Authority; regulatory part of Ofgem |
| GJ | Gigajoule (one thousand MJ) |
| GO; GoO | Guarantee of Origin |
| Greenhouse gases; GHG | Gases whose emission contributes to climate change; The Kyoto Protocol identifies these as Carbon dioxide, Methane, Nitrous oxide, Hydrofluorocarbons, Perfluorocarbons and Sulphur hexafluoride |
| Green smear-back | See buy-out fund recycling |
| GRC | Gross Registered Capacity |
| Grid Code | The code of practice, which covers all major technical aspects relating to connections to, and the operation and use of, the transmission system |
| GW; GW(e); GW(th); GWh | Gigawatts, Gigawatt-hours electricity, Gigawatt-hours thermal |
| HFCs | Hydrofluorocarbons |
| HMSO | Her Majesty�s Stationery Office |
| ICW | Industrial and Commercial Waste |
| IEMD | Internal Electricity Market Directive |
| IFI | Innovation Funding Incentive � a mechanism to encourage DNOs to invest in appropriate R&D; activities |
| I Mech E | The Institution of Mechanical Engineers |
| Intermittency | The non-continuous nature of some forms of energy generation, e.g. wind power, solar, hydro, wave and tidal |
| ISG | Implementation Steering Group for the Structure of Electricity Distribution Charges |
| J | Joule |
| kJ | Kilojoule (one thousand Joules) |
| Ktoe | Thousand tonnes of oil equivalent |
| kVA | One thousand volt-amps; similar to one kW |
| kW; kWh | Kilowatts; kilowatt hours |
| LCPD | Large Combustion Plant Directive |
| LEC | (Climate change) Levy Exemption Certificate |
| LEG | Licence Exempt Generator; an electricity generator too small (<100MW) to be required to hold a generation licence |
| Load factor | See capacity factor |
| LZC | Low and zero carbon (as applied to energy and energy conservation measures) |
| MJ | Megajoule (one thousand kJ) |
| MO; MOA | Meter Operator (Agent); responsible for installation, safety and maintenance of metering equipment on behalf of the electricity supplier/meter registrant |
| MPAN | Metering Point Administration Number; The registration number of a metering point used in electricity settlement |
| MRA | Master Registration Agreement; The multilateral framework agreement for the retail (SVA) level procedures of registration and transfer |
| MSW | Municipal Solid Waste |
| Mtoe | Million tonnes of oil equivalent |
| MW; MW(e); MW(th); MWh | Megawatts |
| Megawatt-hours |
| NAP | National Allocation Plan for the level of emissions permitted under the EU ETS |
| NETA | The New Electricity Trading Arrangements; introduced in March 2001 for England and Wales and governed by the BSC |
| NFFO | Non Fossil Fuel Obligation (described in Section A2) |
| NFPA | Non-Fossil Purchasing Agency; administers the NFFO contracts and auctions NFFO energy and ROCs |
| NFPAS | Non-Fossil Purchasing Agency Scotland; administers the auction of SRO ROCs |
| NGT | National Grid Transco; the GB Transmission System Operator for electricity and gas under BETTA |
| NIAER | Northern Ireland Authority for Energy Regulation; created on 1 April 2003 (see also Ofreg) |
| NIE | Northern Ireland Electricity, part of the Veridian Group |
| NI-NFFO | Northern Ireland NFFO |
| NOx | Nitrous oxide and other oxides of nitrogen |
| NPPG | National Planning Policy Guidance documents published by the Scottish Executive |
