Next week, the GHG will open a public consultation on the protocol’s plan to move to hourly matching in Scope 2 emissions reporting. This move would align international reporting standards with the physical reality of the grid, closing a loophole that currently allows energy consumers to claim they are using solar power at night or wind power on still days. It’s a move that we at Matched strongly support.
A subset of stakeholders have raised concerns about the move to hourly matching. They cite data gaps, infrastructure limitations, and implementation costs that could potentially impact the voluntary renewable energy market. Energy buyer consortiums highlights "serious implementation challenges." Polls find that 80% of companies lack confidence they can comply.
At Matched Energy, we've explored these challenges and believe many concerns can be addressed with existing resources. Using only public data, we already calculate half-hourly renewable matching scores for every major UK energy retailer across 213 TWh of consumption and 17,520 half-hourly periods. This calculation is not compute intensive; we are able to run our analysis on a single Macbook Air.
This pattern of initial resistance followed by adaptation has historical precedent. When new regulatory frameworks like GDPR were proposed, companies expressed similar concerns about technical feasibility. Yet markets adapted, systems evolved, and business continued. The same progression seems likely with hourly matching: initial concerns, followed by gradual adaptation as implementation pathways become clearer.
The data already flows through our grids
Corporate stakeholders note that hourly consumption data "remains unavailable for most facilities." While utility bills typically don't currently show hourly breakdowns, the underlying data necessarily exists within grid systems.
In the UK, that data is public. Elexon publishes half-hourly settlement data for every balancing mechanism unit on the grid. Every retailer, every half-hour, every day. This information is available in S0142 files. Ofgem tracks supplier’s claims on renewable generation through REGOs with monthly granularity. The National Energy System Operator provides real-time generation mix data.
At Matched, we’ve developed a methodology to connect these data sources, spending time mapping REGO generators to grid balancing units in order to produce half hourly matching scores for suppliers. If a small team like us can accomplish this for all major UK suppliers, it's surely the case that large corporates can do the same for their own needs.
The primary challenge appears to be that many companies haven't yet explored available data sources rather than fundamental data unavailability.
Calculating hourly matching scores for UK suppliers
The UK doesn't yet have hourly REGO certificates, but we can still calculate temporal matching with good accuracy for carbon accounting purposes. We use monthly REGO volumes and distribute them according to actual generation patterns from grid data. While hourly certificates would be definitive, our approach is accurate to within a couple of percentage points, and vastly improves on annual matching.
Our analysis reveals meaningful differences between suppliers: some deliver 55% renewable electricity despite "100% renewable" claims, while others achieve 88% when measured half-hourly. These variations matter for understanding which suppliers are investing in renewable procurement that aligns with their customer demand, versus suppliers that purchase all of their renewable certificates in times of the year when renewables are plentiful and cheap.
Our methodology could work in any market with basic grid transparency and publicly available data.
Measure first, then improve matching
Some stakeholders have expressed concerns that hourly matching would necessitate contracts for "400% of consumption". This assumes companies must achieve perfect 100% hourly matching. However, the GHG Protocol focuses on reporting actual achievement levels rather than mandating 100% hourly matching.
We’re already seeing corporates like Google and suppliers like Good Energy publishing hourly matching without claiming perfection. 100% hourly matching may be the long-term goal, but that shouldn’t prevent energy consumers from using honest accounting rather than annual matching targets which don’t reflect the physical reality of the grid.
Temporal transparency will drive market innovation. When consumers can see actual renewable delivery patterns, market forces should encourage improvements. Storage becomes more valuable, demand flexibility gets rewarded, and grid systems evolve accordingly.
This mirrors outcomes from nutrition labelling, energy efficiency ratings, and emissions standards, where transparency drives performance improvements over time.
Public data as a foundation
Several practical steps would accelerate a transition to a reality-based scope 2 accounting system:
- First, regulators around the world could expand data publication requirements. If Elexon can publish UK settlement data, other grid operators could implement similar transparency measures. If Ofgem makes REGO data public, other renewable certificate registries could adopt comparable approaches. Much of this data exists within existing systems and could be made accessible. If any regulators around the world are reading this, we’d love to talk about what this would involve.
- Second, companies could begin working with currently available data rather than waiting for perfect solutions. Our methodology demonstrates meaningful temporal matching using existing public data. Enhanced infrastructure via hourly certificates will certainly help, but the public data along is already an excellent yardstick by which to accurately measure renewable energy consumption.
- Third, markets with published data could serve as development environments. Many countries could learn from the UK, and the UK government should be proud of the level of data transparency that has been achieved.
We've published our complete methodology, including all calculations, data sources, and assumptions. This demonstrates that organisations with modest resources can develop workable approaches to hourly matching. If you’re an energy consumer in the UK that wants to understand how different suppliers compare on hourly matching, please get in touch.
Overcoming implementation hurdles
The concerns that companies are expressing about the GHG’s plans isn’t unexpected. Companies are adapting to a significant shift in accounting methodology. Many organisations have developed systems around annual certificate matching, which was appropriate when renewables were limited. But this change is necessary. Today, with wind and solar regularly exceeding 80% of UK generation, more granular tracking is necessary.
The data challenges identified by stakeholders are implementation hurdles rather than fundamental barriers. Most corporations discussing hourly matching have substantial technical resources, utility relationships, and IT capabilities that exceed those available to smaller organisations like Matched.
What's needed is organisational prioritisation and resource allocation. The GHG Protocol changes provide that business case.
Hourly matching is coming
The shift to hourly matching isn't a distant technical challenge—it's an immediate opportunity. We've proven that accurate renewable energy measurement is possible today using existing data and standard engineering approaches.
Whether you're an UK energy consumer wanting to understand your supplier's true renewable delivery, a corporation preparing for 2027 requirements, or an organisation working to improve energy system transparency, the tools and methods already exist.
Matched will be publishing its 2025 Clean Power Index on October 27th, which will provide hourly matching scores on all major UK suppliers using public data. If you’d like to preview the scores or find out how our data can be useful to your organisation, please get in touch.