Of the some 2,206 businesses in the U.S. that provide solar panel installation services, there are about 257 solar companies at work throughout the value chain in Illinois. Last year, $16 million was invested on solar installations in Illinois, and six million megawatts of solar electric capacity was installed.

And thanks to a new method, storing that energy might get even cheaper.

The École Polytechnique Fédérale de Lausanne (EPFL) has developed an unconventional way to fabricate high-quality, efficient solar panels for direct solar hydrogen production at a low cost.

Storing solar energy as hydrogen can provide a way to develop comprehensive renewable energy systems. In order to do so, traditional solar panels can be used to generate electric currents that split water molecules into hydrogen and oxygen, the former being considered a form of solar fuel.

However, solar panels that can split water molecules are exorbitantly expensive to produce, which is why the EPFL’s new solar panels are so exciting.

Of the many different materials that have been considered for use in direct solar-to-hydrogen conversion technologies, “2-D materials” have been the most promising, thanks to their extraordinary electronic properties. In order to produce large areas of solar panels made using expensive, 2-D materials, the EPFL found an innovative, cost-efficient method that uses the boundary between two non-mixing fluids.

Researchers injected tungsten diselenide, a highly efficient, highly stable 2-D material, in between the two non-mixing fluids. Exploiting the oil-and-water effect of the non-mixing fluids, the EPFL used the two liquids as quasi-rolling pins to force the 2-D material into a thin film. They then removed the non-mixing liquids, and transferred the film to a flexible plastic support.

The thin film was found to be more efficient than other films produced of the same material, but through different methods. It was also far more affordable to make, making it suitable to for commercial level scale.

“It is suitable for rapid and large-area roll-to-roll processing,” said Kevin Sivula of the EPFL. “Considering the stability of these materials and the comparative ease of our deposition method, this represents an important advance towards economical solar-to-fuel energy conversion.”