Game changers spell end for old petroleum age

Every few years, the engineers toiling to supply energy to the world achieve advances that qualify as game changers. But often, the breakthroughs go unnoticed.

That may be because energy companies hate to broadcast details of their cutting-edge technology to rival firms. Or the key improvements may be too subtle to impress outsiders.

It is only years later that their profound impact on energy supplies and patterns of use become clear.