The body heat of about 250,000 commuters in Stockholm’s Central Station is now being used to warm a building across the street. Engineers and designers in Sweden have figured out a way to harness the excess heat energy from the activity of people who pass through the station each day. The technology works through the use of heat exchangers installed in the station’s ventilation system that convert the heat into hot water. The technology has been around for a while. The difference is the water is then pumped to the heating system in a nearby building to keep it warm.
By passing off excess heat generated from one building to another, the Swedish designers believe they have found an efficient way to harness usual waste energy in a place where fuel is expensive and the winters are very cold. They expect this human heat energy will be able to supply as much as 25 percent of the building’s heat.
Is the development of urban heat distribution networks the wave of the future?
The concept of using energy lost as heat is not entirely new; it’s a matter of efficiency, storing the energy and powering the device.
Researchers at the University of California, Berkeley and the U.S. Department of Energy’s Lawrence Berkeley National Laboratory developed a technology of “rough silicon nanowires” that could use body heat to recharge cell phones and other electronic devices.
There’s also POWERleap, a technology that uses piezoelectricity, or harnessing energy produced through walking (and potentially traffic) through a flooring system made of materials that release a charge when force is applied. Says the company:
The electricity generated from the system can be stored and used in a wide variety of applications to create a self-sustaining closed loop system. In large installations the electricity can also be fed back into the grid.
The energy is likely best used for simple powering systems, like switching things on and off or creating small trickles of battery storage.
Bustling spaces like bars, a farmers’ market and commuter stations could employ the technology in the future. Since 2006, the East Japan Railway Company, for example, has been testing ways to utilize power generated from transit customers entering and exiting ticket stations. In 2009, the transit company installed a set of “power generating floors” at seven ticket stations. The hope is such technology could be used to power automatic ticket gates and electronic display systems for the railway company.