Sometimes it would be useful with an easier way of getting some extra energy. Especially when coming home after a long day at work. What if we could just plug in to the electricity outlet and skip the dinner?

We asked a associate professor Kjell Waltersson at Mälardalen University how much energy really is needed to power a human. After some calculations we realised that a typical guy or girl would need to consume approximately one AA-battery per minute in order to function normally. So hamburgers and all the other stuff we digest must do a pretty good work in terms of energy.

The other way around, that is – using humans to generate power, is more common. For example, Portland’s green gym will have spinning bikes connected to wind-generator motors. The users should generate enough electricity to power the gym’s music system or run personal DVD players on the machines, the gym’s manager Adam Boesel predicts. An other example is the power-generating dance floor in the UK.

In Sweden, the planners of Kungsbrohuset is doing a good job designing for a system that harnest energy from the over 200.000 people walking under a building at the Central station in Stockholm. 10 percent of the building will be heated by humans.