Jeremy Rifkin is nothing if not provocative. His CV includes protests over the Vietnam war, campaigning against genetic modification and the prophecy that advances in information technology would mean the “end of work”. In the 21st century, he has joined the battle over the future of energy, championing the causes of small-scale electricity generation and hydrogen fuel cells.

He remains a controversial figure, described dismissively as a “futurologist” by some and a “Luddite” by others. But his vision of a “third industrial revolution” in energy use has brought his ideas to the heart of power in the European Union. Jose Manuel Barroso, the European Commission’s president, used the phrase in a speech in Madrid last month.