Mining Underground Waste Heat
After a long and satisfying dinner on Saturday night, I walked into Union Square Station to catch a ride back to downtown Brooklyn. It was late and the train missed its schedule as usual. However this time I spent enough time waiting to realize that the soaring temperature in the subway station could be uncomfortable and valuable at the same time. “ This heat will be a friend to me when it’s winter time.” I thought.
In fact the underground waste heat could be used for greater goods anytime. Researchers in London are planning to recycle the waste heat in underground power distribution cable tunnels . By their calculation, a 1.8 kilometer cable tunnel could emit enough energy to heat 100 homes above the ground. The technology to exchange heat is also mature: a fan coil transfers heat from air to circulating water which then can be piped to a heat pump. Not only could the heat exchanger recover some the wasted energy, it could help lower the temperature within the tunnel as well.
There are many untapped waste heat sources in the city besides power cable tunnels: sewers, data center, underground railway tunnels… The heat exchange technology could be deployed anywhere where there is a big and energy- inefficient system. The wide application of this technology definitely will help improve energy efficiency of the city and particularly may serve as an “air conditioner” for underground railway passengers. Of course it is up to data scientist’s to identify the optimal locations for heat exchangers in the vast underground worlds in order to make the plan business viable.
References
[1] Patel, Prachi. (2019 September 11). London’s Hidden Cable Tunnels Could Warm thousands, IEEE Spectrum , retrieved on September 15, 2019, from https://spectrum.ieee.org/energywise/energy/environment/londons-hidden-cable-tunnels-could-warm-thousands-of-homes
