Researchers have developed a new type of solar fuel cell that they claim is 10 times more efficient and uses 10,000 times fewer precious metals than current solar fuel cells.

So, first of all, what is a solar fuel cell?

The easiest way to explain it is by pointing to the slow-burning battle between hydrogen- and electric-powered cars. Tesla has the market cornered on fully electric, premium vehicles (EVs), but Toyota recently released its own hydrogen-powered competition last year. EVs are self-explanatory, but a fuel cell vehicle basically runs the same way a conventional car does, except with hydrogen instead of gasoline (and minus the carbon emissions).

The problem with hydrogen is that it’s not that easy to come by. One method of obtaining it is by using a “water-splitter” that separates hydrogen and oxygen molecules. The process is called electrolysis and it is a zero emission process. However, it’s not cheap to do. This is one reason why Elon Musk, CEO of Tesla, has referred to fuel cells as “fool cells” (among other, less-PG epithets).

However, some researchers are looking at ways to use solar power to electrolyze water. and that’s where the new prototype developed by Eindhoven University of Technology (TU/e) and the FOM Foundation comes in.

The new nanowire prototype

The electricity from a solar cell can be used to initiate chemical reactions, such as splitting water. Up to this point, doing so is prohibitively expensive, but researchers may have made a breakthrough. TU/e and FOM have stated that gallium phosphide (GaP) may be the “dream candidate” material they’re looking for.

Today, if you want to split water, you connect an electrolyzer to a silicon battery. It works but it costs. Therefore, why not kill two birds with one stone and use a semiconductor material that converts sunlight into electricity and also splits water?

The prototype recently presented in the journal Nature Communications is composed of a grid of very small GaP nanowires. While GaP cannot easily absorb light when laid out in a large flat surface, arranging it into a grid solves that problem, allowing the fuel cell to take fuller advantage of GaP’s natural electrical properties. It also saves on material – by a lot.

“For the nanowires we needed ten thousand less precious GaP material than in cells with a flat surface,” said Dr. Erik Bakkers, who worked on the project. “That makes these kinds of cells potentially a great deal cheaper. In addition, GaP is also able to extract oxygen from the water – so you then actually have a fuel cell in which you can temporarily store your solar energy. In short, for a solar fuels future we cannot ignore gallium phosphide any longer.”

It’s not a miracle solution just yet. Even though GaP increases the hydrogen yield by tenfold, it’s still only 2.9 percent. That’s a record for GaP cells, but silicon cells yield 15 percent hydrogen when connected to a battery.

For now, it looks like Elon Musk still has the final word (jump to 10:20 in the video below):