Energy-guzzling data centers pump out an estimated 200 million tons of CO2 emissions every year around the world–more than 42 million cars create in the same amount of time. While companies like Google are starting to use wind and solar power to tackle the challenge, a Swedish startup is going a step further: The new EcoDataCenter will be “climate positive,” generating extra-clean energy it shares with nearby houses.
Located north of Stockholm in Falun, a small town once known for mining, the data center–which begins construction next year–will run on a mix of solar, wind, hydropower, and wood chips and sawdust from local forestry. But the next step in the process is what makes the data center unusual.
As the servers run, they generate heat that would normally be wasted. The heat is hooked up to the town’s district heating system, sending hot water to warm up local homes in the winter. In the summer, the system can supply district cooling, running air conditioning that would otherwise use electricity.
“We are able to reuse all of the energy, all year long,” says Jan Fahlén, who works at Falu Power and Water, a local energy company that partnered with entrepreneurs to design the data center. The system can also convert heat from the servers into a cooling system to make them run more efficiently; typically, as much as half of the energy in a data center is used just to keep servers cool.
“This allows us to offer lower costs for our customers, even though it is a high-performance data center,” he says. In total, the system will be 20%–25% cheaper to run than comparable state-of-the-art data centers.
In the coldest parts of the Swedish winter, the data center will use small amounts of fossil fuels. But because that’s offset by helping the rest of the town use less energy, the net effect is that the data center has a negative carbon footprint in a year.
One reason the system will work is that the town already had the right infrastructure. By locating the data center next to the local power plant–which already was connected to district heating and cooling–everything will be fairly easy to set up. Still, the founders think that the same thing can happen elsewhere.
“I’m sure that others will follow us in one way or another,” says Fahlén. “Of course, our situation is somewhat unique due to the closeness to the infrastructure and to the energy system, but there are more places in Sweden and probably in the world where others can follow our example.”
In places without district heating and cooling–i.e., most cities, especially outside Scandinavia–data centers might be able to follow a different example: This German company is experimenting with putting servers in people’s homes to warm them up directly.