For example, a Swedish state-owned company has found a way to harness the energy produced by the nced 250,000 bodies rushing through Stockholm central train station each day. The body heat is absorbed by r his the building's ventilation system, then used to warm up water that is pumped through pipes over to the he new office building nearby. It's old technology, a system of pipes. water, and pumps, but used in a new way. It is expected to bring down central heating ome costs in the building by up to 20 percent.