Sunday, April 13, 2008

Could Chemical Solar Power Beat Photovoltaics?


Could a vat of chemicals be a more effective way to harness the sun's energy than those fancy, intricately crafted silicon wafers? We're not sure, but Professor Chaurasia of the University of Birmingham, UK, was telling me about that possibility earlier in the month.

He's developing a unique process in which propanol is dehydrogenated using a catalyst and clean, solar energy. The hydrogen then generates electricity - courtesy of a Proton Exchange Membrane fuel cell. The byproduct of dehydrogenated propanol -- acetone -- and the protons (H+) and electrons (e-) then all recombine to form more propanol, which is then ready to start the project all over again.

Very simply, it's a way of harnessing the instability of propanol to push electrons onto the grid. It's not a new way of creating hydrogen, it's a new way of harnessing the sun's power using the versatility of hydrogen, and the instability of propanol. Indeed, it's pretty genius.

But the question of economics remains. Current solar cells are getting cheaper and more efficient every day. And though Chaurasia thinks that his chemical cells could be competitive, that will depend on several factors. The propanol is cheap, PEM fuel cells and titanium catalysts are not, so we will have to wait for these "solar fuel cells" to scale up before making any real judgments.

Chaurasia's most recent paper was published in the International Journal of Sustainble Energy.

No comments: