“In 1973, when OPEC started to multiply oil prices, I rashly predicted: ‘The age of cheap power is over – the age of free power is still 50 years ahead.’

Three decades on, there are promising signs that we may soon get close to that ideal. There is a real possibility that the most important event of the early 21st century will be the advent of unlimited amounts of clean energy. Does it really matter whether hydrogen or nuclear fusion or another technology will finally liberate us from our current addiction to fossil fuels? Meanwhile, other technologies enable us to adjust our work and lifestyles. For example, mobile phones and the Internet have already cut down a lot of unnecessary travel – and this is only the beginning. We should revive a slogan I coined in the 1960s: ‘Don’t commute – communicate!’”