The City of Seattle is putting a new meaning to the word recycle.

As first reported by The Economist, plans are in the works for the city to take excess energy from data centers to power what’s called a district heating system. Essentially, Seattle wants to use an old school method of heating buildings and spice it up with some modern technology.

District energy systems warm buildings by using heat generated at a centralized location. If approved, Seattle’s new system would move the extra energy from data centers to a district heating system, which would then provide heat to buildings in the South Lake Union area.

The city is in discussions with Seattle Steam, a utility company called Corix and local developers to use excess energy from data centers at the Fisher Plaza and Westin Building Exchange. That system could potentially heat up Amazon’s new towers at its headquarters in South Lake Union.

Right now, excess heat is turned into water and then moved into the atmosphere with cooling towers. That heat is not quite hot enough to keep buildings warm, but an energy spike from Corix could change that.

Other cities, like Helsinki, have tried something similar. Switzerland also used excess energy from an IBM data center to heat up a swimming pool.