Passive houses are built without conventional heating systems and are kept warm by the heat given off by their occupants and electrical appliances. The first passive house in Sweden was a townhouse completed in 2001. Since then, the concept has become more ambitious in scale. Not only have more buildings followed, but larger ones as well. In the southern town of Växjö, there are passive highrises, and in Stockholm, the body heat from commuters passing through the central railway station is used to heat a nearby building.
Harvesting Clean, Renewable Energy from Bodies
As it turns out, we humans are regular dynamos when it comes to generating renewable energy. Recycling our body heat is just one of several people-power strategies that are emerging. Others include generating biogas from municipal sewage as well as scavenging kinetic energy from treadmills and other workout equipment, and wearing solar-integrated fabrics or high tech knee braces to harvest energy from routine movements.