How one UK data centre is future proofing its energy strategy
From theory to practice, here’s how they did it.
As proposed changes to Scope 2 reporting reshape expectations around renewable electricity claims, data centres are coming under increasing scrutiny for how their operations are powered. For businesses supporting AI, cloud and other energy-intensive workloads, traditional certificate-backed renewable supply isn’t always enough to satisfy customer and investor expectations.
In this article, we look at how Stellium, a UK-based, AI-ready data centre operator, restructured their energy strategy to move beyond annual renewable matching – adopting an hourly matched approach designed to support credible sustainability claims, future reporting requirements and long-term commercial growth.
Author, Tom Parsons, is Commercial Director at Good Energy, where he leads teams responsible for renewable energy supply, energy services and product innovation across domestic and business markets. With more than 15 years’ experience across organisations including EDF, Drax and Good Energy, Tom specialises in helping businesses balance decarbonisation with commercial performance through renewable procurement, PPAs and flexible energy strategies.
Why renewable electricity is no longer enough
Across the data centre sector, renewable electricity has become a baseline expectation. But as sustainability reporting matures, not all renewable supply is viewed equally.
Stellium operates a high-performance computing data centre serving customers across AI, technology, government, and other data-intensive industries. As demand for compute grows, so does scrutiny on how that compute is powered.
While traditional REGO-backed supply can support headline renewable claims, Stellium identified a growing disconnect between certificate-based approaches and the expectations of its customers, particularly global technology companies with advanced sustainability frameworks. Increasingly, customers wanted more than annual claims. They wanted proof.
A GROWING CHALLENGE:
The limitation of certificate-based supply
REGOs confirm that renewable electricity has been generated somewhere on the UK grid over the course of a year. What they do not show is when that electricity was generated or whether it aligns with actual consumption.
This creates a credibility gap. Electricity consumed during periods of high system carbon intensity, such as winter evenings, can still be labelled renewable by purchasing certificates from surplus generation at entirely different times.
For Stellium, this presented a commercial challenge. How could they evidence to their customers that they had a green reality rather than just green certificates? As power demand scales, reliance on annual matching alone risked becoming a barrier to securing contracts with customers operating under increasingly rigorous Scope 2 and ESG requirements.
Designing a Scope 2-ready energy strategy
To address this, Stellium implemented an hourly matched renewable electricity strategy with PPAs, achieving a 95.4% hourly matching score – more than double the industry average.
Hourly matching links electricity consumption with renewable generation on an hour-by-hour basis, providing a far clearer picture of how demand is being met in real time. This approach aligns closely with the direction of travel for Scope 2 reporting, where time and location are expected to play a much greater role.
For Stellium, this meant being able to demonstrate not just that renewable electricity was purchased, but when it was generated and which assets were supplying the site. At year end, Stellium can report on the specific renewable generators that powered its operations, adding a valuable layer of transparency for customer disclosures.
In reality this means 75% lower actual emissions than just using the legacy certificate approach. And it’s real world emissions that actually matter. This depth of evidence proved difficult for alternative suppliers to match.
A CREDIBLE ALTERNATIVE:
Why asset-backed supply matters
A key differentiator in enabling high matching scores through PPAs is Good Energy’s access to over 3,000 independent UK renewable generators.
Rather than relying on detached certificates, we supply renewables backed by real generation assets, providing additionality and traceability that certificate-only models cannot offer. This supports credible sustainability claims today, while also giving confidence that the strategy will stand up to future regulatory and investor scrutiny.
Just as importantly, our product doesn’t compromise on the commercial fundamentals. The supply structure supports growth without punitive volume tolerance mechanisms, and is underpinned by straightforward processes and active account management.
Positioned for growth
As demand for time-matched renewable electricity accelerates across the data centre sector, Stellium is now well positioned.
Its energy strategy supports customer acquisition, aligns with emerging Scope 2 expectations, and avoids the need for retrofitting solutions onto legacy contracts. Rather than reacting to change, the business has designed its procurement to evolve with it.
This approach reflects a broader shift in the market. Energy supply is no longer just a cost line. For data centres, it is increasingly a strategic enabler.
Keep reading…
Stellium data centre: Full case study
Discover how Stellium achieved a 95.4% hourly matching score with Good Energy.
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