In pictures: Green technologies

The NARO car is a full enclosed two-seater vehicle which is leaned into corners like a motorbike and was developed by Hugh Kemp who used to be a developer for Lotus.

University of Glamorgan's senior lecturer Jonathan Williams developed the bus at a cost of just over �200,000. It is powered by three different carbon-free technologies.

Atraverda's new Ebonex ceramic plates help reduce the weight of lead acid batteries by up to 50% by replacing the lead within them and it has already secured �17.6m in investment.

Connaught's breaking system can be installed on light commercial vehicles like Transit vans and turns lost breaking power into up to 25% savings on a vehicles fuel and CO2 emissions.

Peter Stevens' 50mph Zecars and Zevans (Ze standing for zero emission) are exempt from parking charges and car tax and run on electric batteries which can be charged from home.