| ODPM | The Office of the Deputy Prime Minister |
| Ofgem | The Office of Gas and Electricity Markets; the energy regulator for GB and the RO administrator (see also GEMA) |
| Ofreg | The Office for Regulation of Electricity & Gas; the energy regulator for Northern Ireland, see also NIAER |
| P(number) | BSC modification proposal, published by Elexon |
| Percentage quotas (in RO) | The annual figures for the �Amount of the Renewables Obligation� shown in the Schedule to the Renewables Order |
| PFCs | Perfluorocarbons |
| PIU | The Performance and Innovation Unit of the Cabinet Office |
| PJ | Petajoule (one thousand TJ) |
| PPA / PPC | Power Purchase Agreement / Power Purchase Contract |
| PPS (formerly PPG) | Planning Policy Statements (formerly Planning Policy Guidelines), published by ODPM |
| PV | Photovoltaics |
| PV-UK | The UK Photovoltaics Association; trade association representing the PV industry |
| RAB | The Renewables Advisory Board established by the DTI |
| Rated capacity | The power rating of a generating station, (usually in kVA or MW) at which it would operate under the design operating conditions and input fuel (or resource � e.g. wind speed) |
| RCEP | The Royal Commission on Environmental Pollution |
| RECS | Renewable Energy Certification Scheme; pan-European certificate trading system |
| REGO | Renewable Energy Guarantee of Origin |
| Renewable power | Renewable energy has been defined as �Energy flows that occur naturally and repeatedly in the environment and can be harnessed for human benefit.� |
| RES-E | Electricity produced from Renewable Sources (term used in ERD) |
| RO; ROS | The Renewables Order and the Renewables Order (Scotland), which provide the legislative basis for the Renewables Obligations in England & Wales and Scotland |
| ROCs | Renewables Obligation Certificates, the �currency� of the RO |
| RPA | The Renewable Power Association; trade association representing renewable power producers |
| RPA-gen-DB | The RPA database on renewable generation in the UK from sources detailed in D1 above |
| RPA-plant-DB | The RPA database on generating plant installed or planned in the UK from sources detailed in D1 above |
| RPZ | Registered Power Zone; areas where DNOs develop and demonstrate new, more cost effective ways of connecting and operating generation on their systems |
| RTMA | ROC Trading Master Agreement; the proforma contract for trading ROCs |
| SEPAB | The Sustainable Energy Policy Advisory Board which advises SEPN |
| SEPN | The Sustainable Energy Policy Network established by DTI, DEFRA and ODPM |
| SI | Government secondary legislation known as a Statutory Instrument |
| Smear-back | See buy-out fund recycling |
| SONI | The transmission system operator for Northern Ireland (NIE) |
| SOx | Sulphur dioxide and other oxides of sulphur |
| SRC | Short Rotation Coppice; perennial crop of tree species planted at high density and typically harvested at 3 year intervals |
| SRO | The Scottish Renewables Order |
| SROCs | Scottish ROCs |
| SSEG | Small-Scale Embedded Generator; a small generating plant connected to the electricity distribution network, for some purposes implies a rating of 16 amps or less per phase |
| SVA Metering | Supplier Volume Allocation Metering. The metering normally required for most smaller generators and consumers and registered by suppliers for electricity settlement purposes. See also CVA metering |
| TCPA | The Town and Country Planning Association |
| TJ | Terajoule (one thousand GJ) |
| Toe | Tonne of oil equivalent |
| Transmission network | The electricity transmission system operating at voltages above 132kV (and including 132kV in Scotland) |
| TSO | (Electricity) Transmission System Operator |
| TNUoS | Transmission Network Use of System; charges made by the TSO to users of its system |
| TW; TW(e); TW(th); TWh | Terawatts, Terawatt-hours, Terawatt-hours electricity, Terawatt-hours thermal |
| UKBCSE | UK Business Council for Sustainable Energy; grouping of participants in the energy sector interested in promoting sustainable energy |
| UK ETS | The Emissions Trading Scheme of the UK, to be replaced eventually by the EU ETS |
| WID | Waste Incineration Directive |
