The Earth receives at any given time 120,000 terawatts of sunlight (1 terawatt is 1 trillion watts), whereas the global need of power is 16 terawatts (to increase to about 20 terawatts in the next decade).

This means that 0.013 per cent of the sunlight reaching us is enough to satisfy all our energy needs.

Clearly the challenge is to tap from this endless source of energy, and if we are clever enough renewables will help us keep the lights on and fight climate change at the same time. There's no need for lowering thermostats and jumpers all around, sharing showers and living with frugal amounts of electricity. Our priority has to be to switch to ways of producing clean and abundant electricity, not using less of it.

If we do it well, our high-tech societies can become decarbonised not by decreasing power consumption but by increasing it by as much as our technologies require it.  

The September issue of National Geographic contains an interesting feature article on Solar Energy "Plugging into the Sun". If focuses on the example of the 250 acre compound of 182,000 mirrors in the Mojave Desert, called Nevada Solar One. It is owned by a Spanish utility company and it is capable of pumping 64 megawatts into the grid, enough to serve 14,000 households in the Las Vegas metropolitan area.

It is a success story that needs to be replicated worldwide.

Brunella