Power, politics and datacentres: An interview with Pure DC CEO Dawn Childs

‘There’s a lot datacentres can do to become relevant and beneficial parts of their communities’

Dame Dawn Childs of Pure Data Centres on the conflicting pressures facing the datacentre industry and how it’s trying to turn them into win-win opportunities.

Datacentres are very much in the news right now, thanks to the rising demands of digital business and, of course, AI. Around the globe, tech companies are rushing to install new facilities, and in many places they are already running up against the limits of available space, water supplies, grid connections, planning controls - and local acceptance.

Dame Dawn Childs, CEO of the global datacentre builder and operator Pure Data Centres, describes balancing the demand for and impact of datacentres as a wicked problem - one with so many variables or conflicting requirements that it’s nearly impossible to solve entirely.

But wicked problems can be managed to achieve a greater good and avoid worst-case scenarios, provided there is sufficient cooperation, innovation, and the kind of optimisations that AI/ML itself will hopefully assist with.

Datacentre technology and know-how are advancing rapidly on several fronts, according to Childs, becoming more energy- and water-efficient and with potential to benefit both national infrastructure and local communities.

Cooling and power

“The difference between where they were a decade ago and where they are now is really quite extreme,” she said.

When the goal was simply getting compute resources online and stable, datacentres were horribly inefficient. Then came the adoption of metrics Water Usage Effectiveness (WUE), which tracks water consumed per unit of energy expended, and Power Usage Effectiveness (PUE), which measures the power requirement per unit of compute. Average PUE has fallen steadily from around 2 in 2016 to typically 1.2 or 1.3 today, or even 1.1 in a few cases.

“So that’s brilliant, but I think that has gone largely unrecognised because of the media focus on power-hungry and water-thirsty datacentres,” said Childs. “There’s quite a lot of myth-busting to be done, and of course, we will continue to work to bring those numbers down.”

But as efficiencies improve, so do demands. More compute means more power; more power means more heat.

Passing air over server racks used to be the simplest, safest, and most way to cool them. However, increased power density requirements - particularly as CPUs are replaced by the much hotter-running GPUs - mean that air cooling is no longer sufficient in many facilities. Operators are turning to liquid cooling, which can enable a tenfold increase in power densities, from 10 kW per rack up to potentially around 100 kW.

“It’s not a new technology; it’s just existing technology being applied in a different way to datacentres,” Childs explained.

In liquid-to-liquid cooling, a cold fluid is circulated through a plate across the back of the servers, with a heat exchanger transferring the energy to a larger pool of liquid, often water, potentially even waste water.

Closed-loop systems like these are far more efficient in terms of water use than earlier adiabatic (evaporative) cooling, but there’s a trade-off: they are slightly less efficient in terms of PUE. Retrofitting closed-loop cooling is generally more challenging than adding evaporative systems to air cooling. As a result, some operators - particularly those focused on lowering PUE - are still using adiabatic cooling and even planning more such facilities. However, Childs argues, “My expectation is that, because of water scarcity, particularly in some areas, everybody should transition to closed-loop systems.”

See also: Cooling the Cloud: Is ‘water positive by 2030’ just a pipedream?

Nevertheless, datacentre water use remains highly contentious, despite assurances from trade bodies like techUK that facilities use less water than is generally believed. A significant issue is that many water companies don’t know how much water datacentres consume, and providers aren’t currently required to disclose this data.

The next phase of evolution is immersion cooling, where servers are dipped into a fluid such as mineral oil to further enhance cooling efficiency. “This isn’t about reducing power consumption,” said Childs. “It’s more about accounting for water usage.”

Grid stability and renewables

Power consumption - and its related components: generation, transmission and emissions - are significant variables in this wicked problem. Should datacentres become their own power stations, perhaps through renewables and battery storage? This may be feasible in some locations but in the long term it could create more problems than it solves.

“Generation isn’t the issue; transmission is,” asserted Childs, explaining that many datacentres already have a lot of back-up power installed.

“So it might feel like a win, because you're not dragging the power consumption, or dragging the cost of transmission or whatever away from people or from housing. But actually you're going to just end up with more stranded assets which may or may not be useful going forward. Creating more pockets of generation rather than fixing the transmission challenge is, I think, unhelpful.”

So, should datacentre providers contribute to modernising the National Grid, which in the UK is operated by a private company?

This is a better approach, Childs said, but it requires significant coordination, particularly from government planners. In 2023, the National Energy System Operator (NESO), a new government body independent of generators, grid operators and gas suppliers, was given responsibility to coordinate energy across Great Britain. This is a major step forward, said Childs, but barriers to new grid connections and power transmission persist.

“NESO is well-positioned to critically assess how the country’s energy infrastructure should expand and what generation and transmission upgrades are needed,” she said. “But it works in tandem with Ofgem, the regulator. The mix is complex, and we need faster ways to manage and optimise it.”

For example, recent work on spatial energy mapping, “looked at flexibility of power, availability and where you could build the datacentres, rather than solving for where the datacentres actually needed to be,” she said.

However, datacentres themselves could step up to help address national power distribution challenges, Childs believes.

“There’s a real moment of opportunity. If we want to get to clean power by 2030, then you simply won't be able to do it just by allowing the grid to expand itself ... because there isn't enough infrastructure, there isn't enough time, there aren't enough engineers. So enabling some sort of micro grids to grow up, to then be brigaded back together might be one way to do it.”

Datacentre storage facilities could also smooth power delivery to the grid, reducing reliance on gas and avoiding instability - a win-win, she claimed.

“We already have hundreds of megawatts of stable power available, which could allow NESO to more precisely manage when to switch off wind and solar and when to turn on gas. If we could provide that flexibility, it would help us transition faster toward 2030 goals and potentially unlock better grid connection capacity.”

But this would require greater coordination within a fiercely competitive industry.

“We [datacentre builders and operators, techUK and the supply chain] are currently working with DSIT [Department for Science, Innovation and Technology] to try and help think through the AI growth zones, the national infrastructure. It can be quite slow and also it's quite challenging to come up with that collective industry viewpoint that it meets everybody's requirements.”

Nevertheless, Pure’s experience in Ireland, which imposed a moratorium on new datacentres around Dublin due to grid stress, suggests that constraints may foster cooperation, with industry players coming together to tackle issues of mutual concern. Datacentre customers, such as cloud hyperscalers, won’t wait 10 years for a grid connection; they’ll go elsewhere. “So, as an industry, we need to unblock these issues, and that’s where I think we can enhance collaboration.”

Local impact

Increasingly, datacentres are a political issue. The UK government has now classed them as critical infrastructure. But national politics are one thing, local feelings quite another.

The datacentre industry, its customers and suppliers need to do more to persuade communities that these facilities will benefit them directly.

Childs points to a new 20 MW Pure datacentre campus under construction in Brent, London, as an example of what’s possible. Built on a brownfield site, it will feature a living wall to absorb pollution, as well as forestry, vertical farming, and educational outreach projects that will directly benefit the local area.

“I think there’s a lot datacentres can do to become relevant and beneficial parts of their communities,” she said.