When a key US Senate committee meets on energy security on Tuesday , it will be calling in one of the country’s most experienced oilmen: T. Boone Pickens. Yet the one-time buccaneering oil driller will not be talking rigs and wells. He has been asked to speak about windmills and turbines.

On July 8 Mr Pickens started an all-out attack on the country’s foreign oil dependence. In television commercials and print advertisements across the nation since then, he has warned that America’s oil addiction is threatening its economy, environment and national security.