蜜芽传媒

If you're a resident of Birmingham you may start receiving your power from a somewhat smelly source.

That's because Severn Trent Water has begun powering around 4,000 homes using gas produced from two million people's sewage.

Our Science Correspondent, David Gregory-Kumar, explains how the system works in 90 seconds.

This clip is originally from Drive on Wednesday 1 October 2014.