Green Tariff

Key takeaways

• A green tariff is an energy tariff marketed as backed by renewable generation.
• In the UK, ‘renewable’ supply is typically matched via REGO certificates — one per MWh of renewable generation.
• Quality varies — the strongest green tariffs are backed by power purchase agreements (PPAs) with named generators, not just bulk REGO purchases.

What is a green tariff?

A green tariff is an energy contract where the supplier claims the electricity you buy is matched by renewable generation. In the UK, this is normally evidenced through REGO certificates — Renewable Energy Guarantees of Origin — issued by Ofgem per MWh of renewable output.

All green tariffs are not equal. A tariff backed by a long-term PPA with a specific wind or solar generator is a stronger sustainability signal than one matched only by REGO certificates purchased separately at the year-end.

How to assess a green tariff

1. Ask whether the supply is backed by PPAs, REGOs, or both.
2. Ask for the share of generation that’s contracted (PPA) vs certificate-only.
3. Check how the supply is reported in your Scope 2 calculations.
4. Compare the cost premium vs other ways of reducing emissions.

Sources

1. GOV.UK — Digest of UK Energy Statistics (DUKES)
2. Ofgem — Great Britain’s energy regulator
3. GOV.UK — Department for Energy Security and Net Zero (DESNZ)