Wasting heat is a wasted opportunity
May 8, 2025
Matt Bagwell
Wasting heat is a wasted opportunity - that's why we build data centres in a better way, for everyone.
TL/DR?
- The growth of workloads, most obviously AI and High Performance computing, has a massive cost, of power usage and heat generation.
- 95%+ of that energy could be recaptured and reused, instead of being wastefully vented into the atmosphere.
- This heat energy opportunity is an economic unlock, for business, industry, and communities.
- It is our responsibility to build infrastructure that addresses the climate, and meets the needs of everyone.
We sometimes take it as read that everyone understands why Deep Green cares so much about heat energy recapture and reuse, after all we’ve been capitalising on the principles for nearly a decade. It’s true that in the last year or two, the amount of both industry and secular commentary about energy cannibalisation, use of natural resources, notably water, and unnecessary wastefulness, has grown significantly; many people know that a series of prompts to generate a rather pointless action figure meme could consume half a litre of water.
Let’s start with one data point; just how much heat energy are we talking about?
Taking into account UK data centres, including Private Sector ‘on-prem’ DSRs, colocation facilities like our own, UK-based neo clouds like our friends at Civo, and hyperscale cloud regions from providers like AWS, Microsoft, and Google, the estimate for power usage is somewhere between 3 and 5 TWh a year. Let’s take the middle mark; 4TWh.
Working on an assumption that it’s possible to recapture approximately 96% of that power as energy, UK-based data centres generate approximately 3.84 terawatt-hours of heat per year.
Great but is that a big number?
Put it this way, that’s enough energy to heat approximately 284,000 UK homes for a year. That’s the population of Plymouth, Reading or Derby enjoying reduced heating bills. Alternatively, the heat energy could be put to good use in what we call “industrial ecologies” - where offtakers are in conurbations with data centres. 3.84TWh could heat 384,000 greenhouses throughout the winter. It’s hard to estimate how many greenhouses are used in the UK, but recent commercial greenhouse market analysis from Mordor Intelligence suggests it’s a growth market. See what we did there?
The point is, waste is a human verb, not a noun.
We can - and do - use the heat energy we recapture, priming heat pumps in district networks, and warming water for swimming pools, and in the process reduce the reliance on antiquated fossil fuel technologies.
The cost benefit? 3.83TWh of electricity would cost approximately £1.08 billion at the current average household rate.
Operators who vociferously barricate against heat reuse are more than simply blowing hot air; they are missing the opportunity for everyone.