Hourly matching 2026

Annual vs Hourly Matching: What Buyers Need to Know in 2026

Read time: 5 minutes
Published date: 05/05/2026

Welcome to our latest blog, where Product Manager James McGolpin shares his perspective on the growing conversation around hourly matching.

Over the past few years, renewable electricity procurement has shifted from a relatively settled space into one under much closer inspection from auditors, regulators, investors and, increasingly, internal stakeholders.

For me, that shift really materialised a couple of years ago when REGO prices spiked. What was meant to support renewable generation had, in some cases, become detached from how electricity was being produced and consumed on the grid. Customers were finding it harder to justify buying renewable power, while certificate‑based claims were becoming broader and more open to interpretation. It was at this point, I started questioning what our renewable supply claims were materially evidencing.

Terms like annual matching and hourly matching are now used far more often, but not always consistently. This blog sets out how we look at renewable matching from a product perspective: what different approaches can realistically demonstrate, where their limits sit, and why timing and traceability have become central to the conversation.

Why this conversation matters now...

For many years, annual energy attribute certificates such as UK REGOs served a clear purpose. They helped normalise renewable procurement, supported investment, and aligned well with how markets and reporting frameworks were set up at the time. The challenge is though, that electricity systems don’t operate on an annual basis, they operate in real time and that gap is becoming harder to ignore. You can now be fully covered by renewable certificates on paper, while still consuming electricity during periods when fossil generation is setting the marginal price on the grid. While technically compliant, its become increasingly difficult to explain without stopping to qualify the claim.

As scrutiny has increased, I’ve noticed buyers ask much more direct questions: When was the power generated? Was it available to the grid at the time of use? And what in reality does this represent?

Those questions are why people are taking a closer look at how different matching approaches work in practice, and what they can, and can’t, really show.

A useful distinction I keep coming back to...

Annual matching is really asking, “Have we supported renewable attributes equivalent to our electricity use over the year?”

Hourly matching is asking something more specific: “How closely did renewable generation line up with the power we actually consumed?”

Different matching approaches answer different questions but it’s important to be clear about what each approach can and can't justify.

How annual matching works in reality...

When we talk about annual matching, the mechanics are fairly simple. Renewable certificates are matched to your total electricity consumption over a reporting year, without trying to align generation and use hour by hour.

There’s a reason it’s still widely used. It’s straightforward, it scales across complex portfolios, and it fits with how market‑based Scope 2 reporting has historically worked.

Where annual matching reaches its limits is on timing as it doesn't show when or where electricity was generated or what was happening on the grid when power was actually used. If that isn’t explained carefully, it can be mistaken for real‑time renewable supply, which it isn’t. This doesn't make annual matching wrong, but it does mean its limits need to be clear. A defensible way to frame it, would be for example;

“Our renewable electricity claim is based on annual certificate matching and doesn’t represent real‑time alignment of renewable generation and electricity use.”

Why timing keeps coming up...

Electricity demand and generation change constantly, hour by hour, day by day, and season by season and grid carbon intensity follows those same patterns.Because of that, some stakeholders are no longer comfortable relying on annual totals alone. They want to know whether renewable procurement temporally lines up with what was happening on the grid when electricity was used.

That shift in focus is what’s brought timing into the conversation now and why hourly matching is getting more attention.

What impact does hourly matching have?

Hourly matching looks at electricity consumption and renewable generation on the same time interval, typically hour by hour, using time‑stamped data. Instead of producing a single annual outcome, it gives you an hourly matching score, a clear KPI demonstrating how carbon-free one’s energy use is at any particular moment.

It should be said hourly matching isn’t a silver bullet, on its own it doesn’t eliminate grid emissions or mean renewable power was physically delivered to a specific site. What it does do is remove a layer of abstraction, shifting the conversation closer to the realities of the grid thereby giving a more honest view of how renewable generation was able to meet demand.

A sustainability journey...

Hourly matching is a direction of travel, and as with many other areas of an increasingly complex grid there are technical hurdles to overcome in order to unlock additional levels of insight. Data integrity and digital infrastructure pave this particular path, but against the backdrop of MHHS and GHGP scope 2 revisions they are genuine added value investments, and it should be considered that having a matching score, whatever it is, represents progress. Early adopters have a rare opportunity to get ahead of the regulation and realise the benefits of this emerging tech sooner as well as engaging in intelligent procurement to boost their score long term.

Regulation, credibility and risk...

Evidence increasingly suggests that time‑based approaches give a more accurate view of emissions and reporting expectations are evolving accordingly. Proposed updates to the GHG Protocol Scope 2 guidance introduce ideas such as deliverability and time‑based matching that increase the level of scrutiny underpinning frameworks like the European Sustainability Reporting Standards.

Soon organisations will undergo closer audit and assurance will need to evidence those claims. Approaches that improve transparency around timing can make those conversations easier and more robust.

Choosing an approach that fits...

When it comes to choosing an approach, internal alignment is usually the most important step:

What claim are we specifically trying to make?
Who is the audience that needs to understand or assure it?
What evidence can we show to support it?

For some organisations, annual matching will continue to make sense, particularly where simplicity, scale and consistency with existing reporting are the priority. For others, hourly matching offers deeper insight into how consumption and renewable supply interact over time.

In practice, many organisations are taking a progressive approach: establishing a clear baseline, then adding more granular methods as data, governance and confidence develop.

Communicating with confidence...

In 2026, it is becoming clearer what each claim actually represents, and precision about which approach was taken will be the new expectation. Understanding the difference between annual and hourly matching is a key part of communicating renewable supply with confidence.