Returning to a world of low individual energy consumption, as it was in the past, seems extremely unlikely: we drive cars, we have refrigerators in our homes, heating and cooling systems, various appliances, computers, televisions and so on. The new middle classes, especially in Asia, want to move, consume and live a life with discreet comfort. Therefore, energy consumption is set to grow in the near future.

And so, for truly environmentally sustainable development, it is necessary to produce non-polluting renewable sources (so excluding nuclear, which is renewable but has the serious problem of nuclear waste), but above all to make production and consumption more efficient. Attention, experts say, has long since shifted from the problem of sources to the problem of energy.

And here comes the big problem: energy can be produced and transported, but hardly stored. The latter is the most important issue for the major sources of renewable energy: the wind does not always blow at the same speed and in the same direction, it rains more and more irregularly and inconstantly, and the sun is only there by day, and only if it is not obscured by clouds. So the energy from water, sun and wind has big production peaks, maybe at times when consumption is lower, and a great scarcity of production at other times, where consumption is higher.

This is why research is now focusing on two aspects: reducing the production costs of renewable energies to make them more competitive, and allowing better preservation of electricity for the end consumer. A good part of the future of humanity depends on the future of this scientific research and technical efforts.