Harvesting the kinetic energy generated by crowds of people is one of our favorite approaches to renewable energy. Recently Netherlands-based Natuurcafé La Port installed an energy generator in a rotating door, so every time someone walks in for a cup of coffee, they give just a little bit of their energy back to the coffee shop. We keep saying that solving the problem of global warming will require that we open up new doors in the field of renewable energy, but we must admit that we never expected to mean it literally!
The door was part of the refurbishment of the Driebergen-Zeist railway station designed out by architecture firm RAU and built by Boon Edam. The door is expected to generate around 4600 kwh of energy each year, which may not sound like much – but every little bit helps. To enhance the design, the team decided to include a transparent ceiling to show how the system works, and LEDs display the amount of energy that it is generated each time someone walks in the door.