Let there be light: The world’s largest 'artificial sun' gets switched on

German scientists will switch on “the world’s largest artificial sun”, an array consisting of 149 industrial-grade film projector spotlights, in the hope that intense light sources can be used to generate climate-friendly fuel.

The Synlight experiment in Jülich, near Cologne, produces light about 10,000 times the intensity of natural sunlight on Earth. All the lamps can concentrate light on a single spot measuring 20 x 20cm, and can generate temperatures of around 3,500°C.

The aim of the experiment is to come up with the optimal setup for concentrating natural sunlight to power a reaction to produce hydrogen fuel, as much of the Sun’s energy remains untapped.

Solar power stations that use mirrors to focus sunlight onto water are already well established. These work by harnessing heat from the sun to produce steam that turns turbines and generates electricity.

The Synlight experiment is investigating the possibility that a similar setup could be used to power a reaction to extract hydrogen from water vapour, which could then be used as a fuel source for aeroplanes and cars.

Synlight currently uses a vast amount of energy – four hours of operation consumes as much electricity as a four-person household in a year – but scientists hope that in the future natural sunlight could be used to produce hydrogen in a carbon-neutral way.

“We’d need billions of tonnes of hydrogen if we wanted to drive aeroplanes and cars on CO2-free fuel,” said Professor Bernard Hoffschmidt, research director at the German Aerospace Centre. “Climate change is speeding up so we need to speed up innovation.”

In the future, the facility may be used to test the durability of space travel parts when blasted by solar radiation.