First they brought us the sweet sounds of ABBA and Ace of Base. Then they delighted us with the home decor empire Ikea. Now Sweden’s hottest idea export is a clever source of cheap and renewable energy: body heat capture. Stockholm Central Station is the busiest train depot in Scandinavia with over 250,000 travelers and shoppers bustling through each day. Engineers for real estate company Jernhusen figured out how to harness the heat energy generated by the moving bodies and use it to heat an office across the street, lowering that building’s energy bill by 25%.
There are about 250,000 people a day who pass through Stockholm Central Station. They in themselves generate a bit of heat. But they also do a lot of activities. They buy food, they buy drinks, they buy newspapers and they buy books. All this energy generates an enormous amount of heat. So why shouldn’t we use this heat. It’s there. If we don’t use it then it will just be ventilated away to no avail. — Klas Johnasson, one of the system’s creators and head of Jernhusen’s environmental division
The commuters in the train station aren’t left out in the cold to warm the office dwellers across the street. What happens is Central Station is heated appropriately, and then heat exchangers in the ventilation system convert excess body heat into hot water, which is then pumped into the office’s heating system. This isn’t the first instance of body heat harvest, but it is the first to figure out how to transfer energy to a different location. Can you imagine how much clean, renewable energy could be generated by the sofa-slipcover-seeking hoards of the 316 Ikea stores worldwide? Sounds like a match made in Sweden.