Matched Clean Power Index
22 comments
·November 2, 2025PaulKeeble
The fact they have Drax energy at 88% tells me they are counting the giant coal factory converted to burn the worlds forest as renewable, it definitely is not just because its biomass. They also have EDF energy, the nuclear power producer, very low tells us they are counting Nuclear as a none renewable. They aren't looking at temporal moves of energy either, which is a big part of Octopus energies customers who are solar and battery owners and do a lot of energy shifting for the grid. These three components mean the wrong companies are at the top and bottom. This index is useless as it stands its not about who is good for the environment and not.
The fundamental idea we need, but the implementation here is just terrible they aren't promoting the right things and it makes me wonder who is really behind this given the bad producers who have got themselves to near the top.
bensg
Thanks for the feedback. You raise three important points that I'll address in turn:
1. Biomass: We report renewables as defined by Ofgem (the UK energy regulator), which for better or worse includes biomass. However, we recognise this is contentious. To address this, we show the breakdown of generating technologies for each supplier so users can see the composition. But regardless, your point is valid and has been raised several times this week, so we have a PR open to add a filter that lets viewers exclude biomass if they disagree with the UK's legal definition.
2. Nuclear: Our initial focus was on renewable power (where intermittency is highest), but we'll be adding nuclear to the index in the next few weeks. This will increase the scores for EDF, Octopus Energy, and British Gas in particular, who purchase the majority of nuclear power. We've called this out in various places on the index (e.g., on the EDF page: https://matched.energy/clean-power-index/edf-energy).
3. Load shifting: Because we measure generation and demand at a half-hourly level, we do account for load shifting that suppliers like Octopus incentivise through agile tariffs. This is actually one of the key advantages of our approach over historic annual accounting; the half hourly temporal granularity means we reward load shifting behaviour.
hedora
Instead of using obviously corrupt measures of sustainability (that have been intentionally broken and game-able for decades) why not calculate net CO2e?
(Or, better, add a toggle to the UI. That will highlight how broken carbon markets and regulatory classifications are.)
hammock
Is CO2e all that matters now for power to be “clean” or sustainable? Seems like that would leave out quite a bit of environmental impact, habitats destruction, air and water pollution, etc
bensg
We're already exploring calculating supplier-level carbon intensities (CO2e), for which hourly matching is a necessary precursor. A toggle between matching score and CO2e rankings isn't a bad idea. Should have some updates in the coming weeks.
toast0
> burn the worlds forest as renewable, it definitely is not just because its biomass
The world's forest is renewable. Maybe the rate of harvest is unsustainable. Maybe the forest is not being renewed for other reasons like the land is being used for grazing or development. But it is renewable.
Krssst
The end result will still be that we'll have less forests to eat some portion of atmospheric CO2 and more CO2 because we burnt wood. What's important is what puts us in a good direction to fight climate change, and burning forests more than they replenish does not sound something that is it.
hedora
Not necessarily. Take the dust bowl for example, or look at global desertification rates. We’re basically burning/eating topsoil. It’s beyond modern technology’s capabilities to manufacture/ replace topsoil, so it’s a non-renewable resource, just like coal.
hammock
By that logic so is oil and gas no?
ZeroGravitas
These voluntary carbon offset things are only ever going to be a step in roughly the right direction.
It feels wrong somehow to be trying to turn them into a perfect way for committed individuals to opt into paying the full price for their individual contribution to only one aspect of the problem.
Instead we should perhaps take a step back and try to assign the costs of the whole system to everyone, regardless of whether they want to volunteer to pay more to make things happen faster.
It interacts poorly with EV or heat pump adoption where volunteering to pay for the last 5% of green electricity could tip the balance against those purchases. But buying them would lower your carbon footprint at even much lower percentage of clean electricity.
Are green conscious consumers ready for the complexity of paying for 95% clean energy?
hedora
The easiest approach is to charge for greenhouse gas emissions at the source.
Set the price to be 2x the cost of direct air carbon capture, then put the money in a fund that pays for cheapest environmentally responsible capture first.
This would lead to ev’s and heat pumps being drastically cheaper than older technologies.
While they’re at it, federalize the price gouging oil companies. We have signs at gas stations run by international megacorps here in California complaining that we have the highest fuel taxes in the US. The taxes are listed on the pumps, by law.
If you subtract them out, and compare the results to other states, you’ll find that we’re being price gouged dollars per gallon by the industries.
(The excuse for this is that there was months-long supply chain shock 20+ years ago. Of course, the prices never went down after that shock…)
Anyway, screw them. We have EVs now, and as bad as PG&E’s rates are, it’s still saving us hundreds of dollars a month.
adrianN
Setting the price that high would mean starvation for a lot of people and this isn’t feasible. Ramping the price up slowly is probably too slow to avoid the worst tipping points, so we need pricing signals together with other policies for the most effective climate action.
djoldman
As far as I know, this results from allowing a producer to produce 100% fossil fuel energy and buy certificates to "convert" that into 100% renewable.
It's an artifact of stuff like carbon credits. Companies like apple, google, and amazon declare that they are carbon neutral, or will be by some date, and what they actually do is burn a lot of fossil fuel but "offset" it by paying for carbon credits.
bensg
Exactly. That’s the core problem the Index exposes. Under current UK rules (and indeed in most countries), suppliers can legally call their power “100% renewable” even when it’s mostly gas at times of low renewable generation. They can do this by offsetting the non-renewable deficit with certificates from sunny summer hours.
What we've tried to do at Matched is make this fact visible, showing which suppliers actually deliver clean power hour by hour rather than just on paper. A number of suppliers (notably Good Energy and Octopus) perform surprisingly well, be procuring renewable power that aligns well with their consumer's demand.
jt2190
Not just burn fossil fuel: They also take some of the money from the credit sale and fund renewable energy production projects, and those will pay back the credit at a future date. (That’s the theory in very broad strokes, as I understand it. Whether that is what actually happens I don’t know.)
dmboyd
“This is not fraud” - that’s a big claim. There’s no accountability for accuracy, so of course there’s some fraud, waste or abuse.
bensg
HN post is linking to our launch announcement. Full index ranking all major UK suppliers is here: https://matched.energy/clean-power-index
evolve2k
I’ve been told that here in Australia our “Green Power” system where well meaning consumers can pay extra for greener power is similarly broken.
A similar index for Australian power would be pretty useful.
bensg
It's absolutely an international problem. As we get more renewables on the grid, we need to move away from the annual accounting mechanism that hides daily and seasonal intermittency.
The amount of open data that's available in the UK is laudable and makes our analysis possible. But we do have some theories about how we can expand to other countries. Australia will be an interesting one, given renewable penetration.
UK suppliers claim “100% renewable” even when selling fossil power at night.
Newly launched not-for-profit Matched Clean Power Index [1] shows, using open data, each supplier’s true renewable share hour by hour.
Built by a small team of engineers and energy analysts — including a former Tesla engineer — it combines half-hourly data from Elexon (demand), National Grid ESO (generation), and Ofgem (REGOs) to calculate the real renewable fraction for every major UK supplier. It's the first open dataset of its kind [2].
The data exposes a £1 billion-a-year distortion: consumers pay for “green” certificates that don’t align clean supply with demand. Redirecting that could fund storage and flexibility instead.
The best suppliers match 69–88% of their demand with real-time renewables — far better than today’s “100%” claims.
We’d love your thoughts on:
- Next features/datasets: storage, nuclear, or CO₂ intensity?
- API design: what endpoints or update cadence would be useful?
- Visualisation: how would you show renewable matching over time?
[1] https://matched.energy/clean-power-index
[2] https://matched.energy/methodology/v1