How these cities are recycling energy from the subway to heat buildings

Several large cities around the world are harnessing the energy emitted by the subway to heat homes. Photo: AFP

What if we recovered the energy emitted by the subway or data centres to heat homes? This technique has been tested for several years in several large cities around the world, including London, Paris and Stockholm.

Perhaps you have already asked yourself, while walking the underground corridors of a big city subway, where the waste heat from the engines ends up. The answer: into the atmosphere.

Yet, this thermal energy emitted by engines, brakes and humans moving in close proximity can be reused via a heat pump to heat buildings. And this is exactly what several cities around the world have committed to doing.