A plan to funnel the heat given off by data centers into nearby homes has run aground in Germany. Across Europe, policymakers are weighing AI ambitions against climate objectives.
Europe is in a bind. It wants to be a leader in artificial intelligence, which requires a lot of computing power—and a lot of data centers. But data centers consume massive amounts of electricity and generate a lot of heat, which is a problem for a continent already struggling to meet its climate goals.
The German city of Hanover was supposed to be a model for how to solve this problem. A new data center, built by Google, was designed to capture the heat it produced and pump it into a district heating network that would warm local homes. But the project has stalled, because the heat isn’t hot enough. The district heating network requires water at a temperature of 80 degrees Celsius (176 degrees Fahrenheit), but the data center can only produce water at 50 degrees Celsius (122 degrees Fahrenheit).
“It’s a setback,” says Frauke Renz, a member of the Hanover city council. “We need to find other ways to use the heat.”
The problem in Hanover highlights a fundamental challenge with using waste heat from data centers: It’s often not hot enough to be useful. Data centers typically operate at relatively low temperatures, and the heat they produce is often diffuse and difficult to capture.
But that doesn’t mean the idea is dead. Some experts believe that with the right technology and infrastructure, it’s possible to use waste heat from data centers to heat homes and businesses. “We need to invest in technologies that can capture and upgrade the heat,” says Jan Eric Sträter, a professor at the Technical University of Berlin. “This includes things like heat pumps and thermal energy storage.”
Another challenge is that data centers are often located in areas where there isn’t a district heating network. This means that even if the heat can be captured, it can be difficult to get it to where it’s needed.
“You need to be strategic about where you build data centers,” says Renz. “You need to build them in areas where there is already a district heating network, or where it’s feasible to build one.”
The European Commission is aware of the challenges and is working on a new strategy for data centers. The strategy, which is expected to be published later this year, will focus on promoting energy efficiency, using renewable energy, and capturing waste heat.
“We need to make sure that data centers are part of the solution, not part of the problem,” says Maria da Graça Carvalho, a member of the European Parliament. “We need to use all the tools at our disposal to reduce their environmental impact.”