A month after launch, we're adding the two most requested features: nuclear tracking and renewable tariff scores.
Nuclear gets tracked
Nuclear generated around 40 TWh in 2024, yet none of it is covered by the certificates that track clean power in the UK. The clue is in the name: Renewable Energy Guarantee of Origin certificates. At Matched, we believe this is an oversight—especially given the need for clean baseload power to complement intermittent renewables.
Starting today, the Matched Clean Power Index will optionally include nuclear power.
The results show meaningful shifts. British Gas jumps 14 places when nuclear is counted. EDF climbs 12. Octopus rises from fifth to fourth position. These suppliers have been delivering substantial zero-carbon baseload power that aren't covered by REGOs.
Several European countries already issue certificates for nuclear. France's Guarantees of Origin cover it. The EU's CertifHy scheme includes nuclear in hydrogen certification. Britain's exclusion is increasingly anomalous, particularly given Clean Power 2030 targets that will necessarily rely on nuclear baseload.
Is it time that REGOs were expanded to cover nuclear too?
Renewable tariff scores
We've also updated our methodology to calculate matching scores at the renewable tariff level. Previously, Matched calculated whole-portfolio scores showing how much renewable power a supplier delivers across all customers. But many suppliers offer both renewable and non-renewable tariffs.
The calculation differs from portfolio scores in one step: rather than looking at demand across the entire portfolio, we examine the demand of customers on renewable tariffs specifically. Suppliers with renewable tariffs commit to 100% annual matching for those products. If a supplier has 1,000 GWh of total demand but procures 800 GWh of renewable supply, renewable tariff customers consume at most 800 GWh. We scale total demand down to match renewable supply before calculating temporal alignment.
We started this work with So Energy, who validated their data with us. They serve 1.2 TWh of total demand and procure 0.7 TWh of renewable supply. Their portfolio score is 51% when measured half-hourly. Their renewable tariff score is 74%.
The 24 percentage point improvement demonstrates why dual measurement matters. Renewable tariff customers are getting meaningfully cleaner power than the portfolio average suggests.
We've now extended this methodology across all major suppliers offering renewable tariffs. The Index shows both portfolio and renewable tariff scores where applicable.
This doesn't apply to suppliers whose entire portfolios are renewable. Good Energy and Bryt Energy don't offer non-renewable tariffs. Their portfolio score already represents what every customer receives.
Next steps
The Clean Power Index and latest version of our methodology is live now.
We're actively working with companies involved in the procurement and supply of energy and the reporting of usage to integrate Matched's data.
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