Basically, what the device does is it takes the heat obtained by concentrating sunlight through the usage of a parabolic dish (solar concentrator) and uses it to transform methane (natural gas) into syngas (carbon monoxide and hydrogen), that has a lower carbon concentration.
The syngas thus produced can be burned in natural gas plants to generate electricity in a cleaner way than burning methane would. It can also be used to make diesel, easier than it is to convert methane into any form of liquid fuel. Still, this technology is subject of debate, since carbon dioxide is emitted while transforming syngas to liquid fuel.
Similar work of using the sun to generate fuel is being done at Sandia Labs, through a project called “Sunshine to Petrol.” PNNL’s approach could be used to generate either electricity or liquid fuels, depending on what proves more economical. Still, Wegeng’s work of transforming methane to fuel via syngas and solar power yields twice the efficiency of regular solar panels (about 30%).
Even though the technology is not perfect it is a step closer to reducing carbon dioxide emissions if applied on a large scale in the near future.