This startup wants to use heat from data centers to warm swimming pools

Deep Green's system could save public pools around $24,000 a year, and cut their annual CO2 emissions by 26 tons.
diving board and pool
Can pools be used to keep servers cool? Markus Spiske / Unsplash

A UK-based startup is aiming to heat swimming pools with its data centers. According to BBC News, Deep Green is using the heat generated by a “washing-machine-sized” server rig to heat the water in Exmouth Leisure Centre’s 25-meter (82 foot) public swimming pool. Its “digital boilers” are a pretty clever idea, and can reduce the environmental impact of both the swimming pool and the server. 

Data centers have a surprisingly large environmental impact. While browsing the web, streaming shows on Netflix, or posting to Instagram doesn’t necessarily feel like you’re doing something that could harm the environment, all the information getting sent to your smartphone, computer, or TV is stored in a data center somewhere. It takes a fair amount of electricity to keep all the servers running, and most importantly, to cool them down so they don’t overheat. 

According to the International Energy Agency (IEA), data centers and data transmission networks account for between 1 and 1.5 percent of global electricity use and are collectively responsible for around 1 percent of energy-related greenhouse gas emissions (or 0.6 percent of total greenhouse gas emissions). While that might not sound like a lot, it puts it in the same ballpark as aviation and shipping, which are responsible for 1.7 percent and 1.9 percent of total greenhouse gas emissions. 

[Related: This Is Why Microsoft Is Putting Data Servers In The Ocean]

This is why Deep Green’s data center solution is so neat. Instead of just relying on electricity—often generated by fossil fuels—to cool its server rigs, the internal components are submerged in mineral oil which absorbs the heat, then a heat exchanger transfers the warmth to a swimming pool full of cold water, which cools the oil and thus keeps the components operating safely. The system is able to convert around 96 percent of the electricity it uses into heat for the pool. And since the electricity only comes from renewable sources, the whole thing as is green as is feasible. 

While the digital boiler can’t heat Exmouth Leisure Center’s pool entirely on its own, it is able to keep the water at a comfortable 86ºF roughly 60 percent of the time. While the gas boiler is still necessary to top up the water temperature, Deep Green claims that its system saves the pool over £20,000 (~$24,000) per year and reduces its annual CO2 emissions by almost 26 tons. Sean Day, who runs the leisure center, told BBC News: “The partnership has really helped us reduce the costs of what has been astronomical over the last 12 months—our energy prices and gas prices have gone through the roof.” 

[Related: Extreme heat is knocking out data centers]

Perhaps most interestingly about Deep Green’s technology, is that it costs the swimming pool operator nothing. The setup, installation, and digital boiler are all managed and maintained by Deep Green. The pool is even reimbursed for the electricity costs of running the server, so all the heat generated is essentially free. Instead, Deep Green operates as a regular web services company, charging its commercial customers for computing power and hosting. 

According to The Next Web, seven other pools around the UK have expressed an interest in Deep Green’s digital boiler. And the company doesn’t just plan to target leisure centers. Its technology can work with anything that requires large volumes of hot water, like apartment heating systems and distilleries. 

Deep Green isn’t the only company looking to repurpose waste heat from data centers. In Finland, the new Microsoft data center will be used to heat approximately 250,000 homes and businesses. A Facebook data center in Denmark warms 6,900 homes, while Amazon uses its data centers to heat its headquarters in Seattle as well as apartments, offices, and university buildings in Ireland. It’s likely that this is an engineering design we’re going to see a lot more of; data centers may heat everything from swimming pools to metropolises.