A REGO — Renewable Energy Guarantee of Origin — is a UK certificate, administered by Ofgem, that proves 1 megawatt-hour (MWh) of electricity was generated from a renewable source. REGOs are the UK equivalent of European Guarantees of Origin (GoOs).
Energy suppliers acquire REGOs equal to the volume of renewable electricity they sell, and customers on REGO-backed tariffs are credited with that renewable supply for greenhouse gas reporting purposes.
Why it matters
REGOs are the principal contractual instrument used in market-based Scope 2 reporting in the UK. A business on a REGO-backed renewable tariff can apply a zero (or near-zero) emission factor to its electricity consumption under the market-based method, even though the physical grid mix has not changed.
Their credibility depends on three things: that the certificates are correctly retired against the customer's consumption, that they are tracked transparently, and that the underlying generation is genuinely additional. REGOs alone do not guarantee additionality — that is, they do not, on their own, prove that new renewable capacity was built as a result of the purchase.
A practical example
An office consuming 50,000 kWh of electricity per year on a 100% REGO-backed tariff would receive REGOs equivalent to 50 MWh of renewable generation. Under the market-based method, that consumption can be reported with a near-zero emission factor; under the location-based method, the UK grid average factor still applies.
We document REGO coverage in every Scope 2 calculation where applicable. See the full approach on the methodology page.