Every major UK energy supplier now markets a 100% renewable business electricity tariff. Most of them are backed by REGOs, Renewable Energy Guarantees of Origin. The question we hear most from sustainability leads: are these tariffs actually green, or is this corporate greenwashing?
The honest answer: it depends on what you mean by green. Here's the unvarnished version.
How REGOs work
A REGO is a certificate issued by Ofgem for every megawatt-hour of electricity generated from renewable sources in the UK. Generators get one REGO per MWh, and they can sell those REGOs separately from the electricity itself.
When a supplier sells you a 100% renewable tariff, what they're actually doing is buying enough REGOs to match your annual consumption. Your electricity is still drawn from the same physical grid, wholesale mix is wholesale mix, but the supplier has retired enough REGOs to claim 100% renewable matching.
The case for REGO-matching
For Scope 2 emissions reporting, REGOs are accepted by Ofgem, the GHG Protocol, CDP and SECR. A business consuming 100% REGO-backed electricity can legitimately report zero Scope 2 emissions from purchased electricity.
For most UK SMEs, this is more than enough to satisfy customer, investor and procurement framework requirements.
The case against
REGOs can be detached from the underlying generation and traded separately. Critics argue this means buying a REGO-matched tariff doesn't drive additional renewable generation, the wind turbine was already going to spin regardless of who bought the certificate.
If your business specifically needs to demonstrate additionality (that your purchase caused new renewable generation), a source-tracked PPA is the stronger option.
What we recommend
For most UK SMEs: a 100% REGO-backed tariff is the right answer. It's certified, recognised by major reporting frameworks, and now within a penny of standard rates.
For larger businesses with public ESG commitments: pair a REGO tariff with an explicit additionality strategy, either a corporate PPA, on-site generation, or both.
Marcus Brown
Sustainability Lead
Part of the Scottish Prime Energy procurement team, 500,000+ UK businesses switched, £150M+ saved.