If you follow the news in the energy world, you will have noted the huge energy needs of data centres. Global energy demand for computer processing has been growing at 12% a year, with AI now added to cloud storage, streaming services, apps and smart devices, and all the many things we do over the internet. Carbon pollution from data centres is now larger than many (small) countries, at around 1% of global emissions and rising.
Data centres use energy in two main ways: running the tech itself, and preventing it from overheating. They generate a huge amount of waste heat, and use air conditioning or water cooling to keep temperatures down. There are lots of projects underway already to address data centre emissions, one of the most obvious being to locate them in colder places. Within the industry there are marketing campaigns touting ‘the Nordic advantage’ of cheap renewable energy and natural cooling.
Another approach is to put all that excess heat to good use. A recent report suggested that the data centres in London produce enough heat to warm 500,000 homes. To get it to them you’d need heat networks to distribute it through underground pipes. Heat networks are more common in Eastern Europe and Scandinavia already, and there is a lot of investment going into them in the UK at the moment, mapping potential heat sources and users. Possible waste heat sources might include factories, refrigerated warehouses, incinerators, and increasingly data centres. One of the first to take advantage of this is Edinburgh University, which plans to use its data centre to heat nearby buildings.
The disadvantage of heat networks is that they only work in specific local areas, usually cities. You’re either connected to one or you’re not. Running your heating system on free waste heat is a nice idea that won’t be accessible to most people.
However, a company called Thermify have a more radical suggestion. Rather than pipe heat out to users nearby, how about putting the data centre in people’s homes? They build distributed network data centres with nodes in people’s homes, about the size of a hot water tank. They then capture the heat from them, store it and and use it to provide on-demand heating and hot water. This means you could quite literally have a small data centre in your house where your boiler used to be.
What’s particularly smart about this is that it creates a market for waste heat. Companies have been paying to take it away, and now they can sell it. Thermify describe this as using energy twice: once for cloud computing, and then again for heating.
It also works well for the home-owner. Because you’re essentially using second-hand electricity, that waste heat can be priced very low. Households will save money on electricity and gas bills, and Thermify are specifically selling their innovation as a solution to energy poverty. And of course it’s low carbon, directly replacing the gas boilers that we need to be phasing out.
Potential downsides? Thermify’s Heathub is pretty small and plugs into existing hot water systems, so it’s not disruptive or expensive to install. I imagine fitting the data centre might be a bit trickier, and it looks too large to fit flats or terraced homes.
I also doubt that it will be a heating solution on the domestic market any time soon, as Thermify probably won’t want to recruit households individually and manage their accounts. Their latest project is in partnership with a council, a community energy project and housing association, and that’s going to be more manageable. But other energy innovations have started with associations and councils and then reached individuals homes, including the Q-Bot underfloor insulation in my own house, so we’ll see.
With my work hat on, I’d invite Thermify to consider data centres in schools as well as homes, which might be simpler and benefit more people at once. (In fact, that’s my homework for later: a persuasive letter to Thermify to suggest they work with schools. I’ll let you know what they say.)
At a time when energy use is falling in many sectors, as standards rise and efficiency improves, computing is bucking the trend. Energy demand for AI and cloud computing is increasing fast. It’s not going to go back in the box, and so we need to think creatively about where we place data centres and what we do with the heat. That makes Thermify one to watch.
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