On the sixth floor of County Hall, the slightly tatty Edwardian building on the south bank of the Thames that once housed the Greater London Council, there is a modest office suite that tells a revealing story about the future of the global energy industry.

With neighbours including a Dalí exhibition, the Manga Studio and the London Aquarium, it is the perfect location for a creative start-up operating outside the mainstream. Only a discreet green and yellow sign with BP’s “Helios” logo and the word “alternativenergy” reveals that it is the base for a division that was supposed to represent the future for one of Britain’s biggest companies.