Why didn't I think of that?

About 250,000 people pass through Stockholm's Central Station each day

Body heat is not an energy source that normally springs to mind when companies want to keep down soaring energy costs.

But it did spring to the mind of one Swedish company, which decided the warmth that everybody generates naturally was in fact a resource that was going to waste.
A real estate company in Stockholm, has found a way to channel the body heat from the hordes of commuters passing through Stockholm's Central Station to warm another building that is just across the road.

Heat exchangers in the Central Station's ventilation system convert the excess body heat into hot water.

That is then pumped to the heating system in the nearby building to keep it warm.

Not only is the system environmentally friendly but it also lowers the energy costs of the office block by as much as 25%.