Seven takeaways from our Nuclear Know-How webinar on powering data centres with nuclear energy

Can nuclear energy help meet the growing power demands of data centres?

Power is becoming one of the biggest constraints on data centre growth. As part of Mott MacDonald’s Nuclear Know-How webinar series, experts from across the nuclear, energy, planning and data centre sectors examined whether small modular reactors (SMRs) could help meet rising demand. Here are seven key takeaways from the discussion.

Artificial intelligence (AI), with its massive global power demand is driving unprecedented growth in data centres, bringing with it a pressing challenge: how to secure the reliable, affordable and low carbon electricity needed to power them. National Grid forecasts that commercial data centre electricity demand could increase sixfold over the next decade, placing growing pressure on energy infrastructure, net zero ambitions and energy security.

Mott MacDonald’s Nuclear Know-How series webinar brought together experts from the nuclear, data centre, energy and planning sectors to examine whether small modular reactors (SMRs) could help meet this demand, the barriers to deployment and the benefits of planning energy and digital infrastructure together.

The webinar is available to watch in full, but here are seven key takeaways from the discussion.

1. Data centre growth is becoming an energy challenge

"Traditionally, data centre loads have been very steady, and the grid has had no problem dealing with that. But the AI loads, the training and the inference could potentially vary by quite a lot."
Venessa Moffat, Data Centre Alliance

The surge in AI is increasing demand for large volumes of reliable, clean and affordable electricity, but AI workloads can fluctuate more sharply than traditional data centre loads. Batteries can buffer sudden changes, while SMRs can adjust output within operational and safety limits; even with a direct supply, exporting surplus electricity to the grid would remain important. Digital growth and power infrastructure must therefore be planned together.

2. Access to power is becoming a competitive advantage

"If you haven’t got a model for your business to secure power for continued growth, you will not have continued growth and you will not be competitive and investable."
Rosa Rotko, Mott MacDonald

Access to power is becoming a strategic business issue, not simply an operational requirement. Data centre operators effectively sell the capacity that enables digital workloads, so future growth depends on maintaining a reliable electricity pipeline and meeting near-term customer demand, often within 18 months to two years, while securing capacity for longer-term expansion.
This is changing site selection. Developers once prioritised connectivity and expected power to follow; larger facilities and grid constraints now make electricity availability and energisation dates decisive. Land and connectivity still matter, but a credible long-term energy strategy is increasingly central to investment decisions.

3. SMRs are moving from concept to credible solution

"Holtec, along with most of the big SMR companies developing right now, is targeting a three-year, three-and-a-bit-year construction timeline."
Gareth Thomas, Holtec Britain

SMRs offer the prospect of firm, low carbon electricity at a scale suited to large energy users. Their modular design allows major components to be manufactured offsite and assembled more quickly, with delivery becoming faster and more repeatable as programmes mature.
That speed will not be achieved immediately. A first project must also pass through planning, licensing and financing, making SMRs a credible long-term option rather than a quick fix. Initial schemes will need to build delivery experience, establish repeatable models and give customers greater certainty over when capacity will be available.

4. Co-location could help unlock the next phase of growth

"There’s a dichotomy between where data centres need to be and the restrictions on where generation stations can go."
Jonathan Douglas-Green, Mott MacDonald

Co-locating data centres and nuclear generation could reduce pressure on the electricity network, while direct or private wire supply may avoid some grid-related costs. The practical challenge is location: many data centres are concentrated in London and the South East, whereas nuclear sites have typically been rural or coastal and remain constrained by siting criteria.

Closer alignment between SMR, data centre and spatial planning – including clearer treatment of data centres in the planning system – could create more viable growth zones. These models must remain flexible, accommodating private wire connections, grid export, battery storage, changing operators and evolving technology rather than locking two developments into a rigid arrangement.

5. Commercial models will be as important as technology

"The delivery certainty is what investors are looking for. We need to know when, where and under what commercial terms SMRs will exist."
Venessa Moffat, Data Centre Alliance

Investor confidence depends on delivery certainty: when projects will be built, where capacity will be available and on what commercial terms. In the United States, hyperscalers – large technology companies that operate extensive, high-capacity data centre networks are signing long-term private power purchase agreements with SMR companies, providing revenue certainty to support investment. The UK cannot simply replicate these models, however; early projects are likely to need strong private backing alongside targeted government support, particularly for risks outside developers’ control.

Commercial structures must also manage mismatched delivery dates. A data centre may initially draw from the grid, while an SMR completed first may need to export power until its customer is ready. Testing such investable structures through first-of-a-kind projects will create the evidence needed for wider deployment.

6. The opportunity extends far beyond electricity supply

"What other industries can we attract to the area? What other high-paid, high-skilled jobs can be transferred into that area because of this?"
Lewis McVey, Mott MacDonald

The opportunity extends beyond electricity supply. Combining nuclear generation and digital infrastructure could support regional regeneration, attract associated industries, create skilled jobs and supply waste heat to nearby networks. Planning these elements together from the outset would be more efficient than retrofitting them into established communities and would embed local benefits earlier.

That wider value will depend on open community engagement. Water demand, emergency planning and local impacts vary by technology and location, so selecting appropriate solutions and addressing concerns early will be essential to building trust and creating lasting benefits for host communities.

7. The future depends on bringing sectors together

"These sectors are very different, but meeting the needs of the modern world requires the nuclear and data centre industries to come together."
Rosa Rotko, Mott MacDonald

Delivering nuclear-powered data centres will require collaboration across sectors with different cultures, timescales and commercial priorities. Nuclear and data centre developers must work with planners, policymakers, grid operators, regulators, investors and communities to define viable projects and resolve barriers before they become embedded.

Demand for firm, low carbon power is clear and SMR technology is advancing. The industries that move first to connect energy, digital and spatial planning will be better placed to secure capacity, attract investment and shape viable delivery models, rather than competing later for constrained sites and grid connections.

For the UK, the implication is strategic. Turning early projects into a repeatable pipeline could give data-intensive industries greater confidence to invest, support regional growth around new energy hubs and create an exportable model for powering AI sustainably. Delay risks making electricity availability a brake on digital growth; coordinated action now could make it a competitive advantage.