Glossary

Carbon Offsetting

A carbon offset is a financial instrument aimed at a reduction in greenhouse gas emissions. Carbon offsets are measured in metric tons of carbon dioxide-equivalent (CO2e) and may represent six primary categories of greenhouse gases. One carbon offset represents the reduction of one metric ton of carbon dioxide or its equivalent in other greenhouse gases.

CERs

Certified Emissions Reduction Certificate - A CER is a certificate which is issued every time the United Nations prevents one tonne of CO2 equivalent being emitted through carbon projects registered with the Clean Development Mechanism (CDM).

CERT

The Carbon Emissions Reduction Target is all about reducing CO2 emissions, one of the main causes of climate change. CERT came into effect in April 2008, and it obliges energy companies to take steps to ensure that the amount of CO2 emissions from homes is reduced. As the name suggests, there's a set target for the amount by which CO2 emissions should be reduced. CERT will be in effect for three years, with the target of making an annual net saving of 4.2 million tonnes of CO2 by the end of the programme.

Ofgem's Information about CERT

LEC

Renewables Levy Exemption Certificates (Renewables LECs) are electronic certificates. We issue them, monthly, to accredited generating stations, for each Megawatt/hour (MWh) of renewable source electricity generated. In the case of NFFO/SRO generating stations we issue LECs directly to the electricity suppliers entitled to receive them. LECs identify renewable source electricity produced by accredited renewable generating stations.

Before it can receive LECs, a generating station must apply to Ofgem for accredited status.

Renewables LECs are part of the evidence required by HM Revenue & Customs to demonstrate the amount of renewable source electricity supplied to non-domestic customers in the United Kingdom. They are used by electricity suppliers to claim the CCL Exemption on non-domestic supply. Suppliers allocate Renewables LECs to a supply pursuant to a renewable source contract.

Ofgem Sustainability Pages

Micro-generation

The generation of zero or low-carbon heat and power by individuals, small businesses and communities to meet their own needs.

National Grid Average Assumption

All energy generated in the UK is sent into the national grid. The energy in the national grid has been generated from a combination of different sources; wind, hydro, biomass, nuclear, coal to name a few. Each different energy source will have created a specific level of carbon dioxide output associated to the source of generation – renewable sources like wind and hydro carry less carbon dioxide emissions than coal generated energy for example. Because we are abating a proportion of carbon of your electricity supply as a part of the Green Energy Certification Scheme all suppliers have agreed to a CO2e that reflects the average mix of generation.

REGO

Renewable Energy Guarantee of Origin certificate) certificate providing evidence that the electricity was generated from a renewable source

ROC

A Renewables Obligation Certificate (ROC) is a green certificate issued to an accredited generator for eligible renewable electricity generated within the United Kingdom and supplied to customers within the United Kingdom by a licensed electricity supplier. One ROC is issued for each megawatt hour (MWh) of eligible renewable output generated.

VERs

Voluntary Emissions Reduction Certificate - A VER is a certificate that is issued every time the United Nations prevents one tonne of CO2 equivalent being emitted through carbon projects not necessarily registered with the Clean Development Mechanism (CDM).