Germany has switched on an 'artificial sun'

The Sun's temperature is about 5,600 degrees Celsius. That's hot. Hot enough that even 150 million kilometers away, here on the surface of the Earth, you can fry an egg with its heat.  

But now it has a rival. German engineers have built what they claim is "the world's largest artificial sun" to investigate new climate-friendly fuels. 

Housed in a three-storey building at the German Aerospace Center in Juelich, about 30 kilometers west of Cologne, the device is comprised of 149 individual xenon short-arc spotlight lamps arranged in a honeycomb shape. By focusing those lights on a single spot, they can create temperatures of up to 3,000 degrees Celsius.

While that's a little short of solar surface temperatures, its location here on Earth means it can produce 10,000 times the amount of solar radiation over the same area as the Sun does. Better still, it can do it whatever the weather conditions.

But why?

The goal is to test new ways of making hydrogen. Normally the gas is made by using electricity to split water into oxygen and hydrogen, but the research team hopes that they can bypass the electricity stage by using energy from sunlight.

That hydrogen could then be used directly for energy (in a fuel cell, for example), or combined with carbon monoxide harvested from power plants to make eco-friendly kerosene, for example. 

"Wait!" I hear you cry. "Isn't the lamp array powered by electricity?" Well yes, it is. About as much in four hours as you'd normally use in a year. So they're not bypassing anything just yet. 

But eventually it's hoped that the principles honed with the artificial sun can be used with real sunlight, scaling it up to a level that's commercially viable. 

Duncan Geere
Duncan Geere is TechRadar's science writer. Every day he finds the most interesting science news and explains why you should care. You can read more of his stories here, and you can find him on Twitter under the handle @duncangeere.