Ensia reports on recent advances in the lab of Daniel Nocera at Hravard in artificial photosynthesis, really an efficient and marketable way to convert diffuse, intermittent store solar energy into storable, highly combustible hydrogen.
Nocera … as well as scores of other researchers around the world, are on the verge of turning the promise of artificial photosynthesis into reality.
In his laboratory at Harvard, Nocera alternates between pacing excitedly and staring listlessly out the window. He seems energized by recent technical achievements, yet daunted by the challenges of bringing the technology to market during the current gas and oil boom.
Since he introduced the artificial leaf in 2011, Nocera developed his own stable, oxygen-producing catalyst that, like JCAP’s encapsulating material, works well with a number of existing light-absorbing semiconductors. Issues of cell durability with the new catalyst have been worked out to the point that he doesn’t even bother testing each new device in water.
“The science is ready,” he says.
What remains a challenge is the economics. The bits hanging from a wire on his bench today are made of crystalline silicon, a semiconducting material commonly used in today’s conventional solar cells. In August, Nocera and postdoctoral fellow Casandra Cox demonstrated a 10 percent solar-to-hydrogen conversion efficiency using the material. Crystalline silicon isn’t the most efficient semiconducting material; researchers at the National Renewable Energy Laboratory in Golden, Colo., have achieved more than 16 percent sunlight-to-hydrogen conversion efficiency using gallium, indium and arsenide. But it is relatively inexpensive — and getting cheaper. With this low-cost material Nocera estimates he could produce a kilogram of hydrogen, the fuel equivalent of a gallon of gasoline, for approximately $2.
“Until you put a price on carbon, none of these technologies are going to get a foothold.” — Daniel Nocera
But even that price, which does not include the cost of the fuel cell that would be needed to convert hydrogen back to electricity, is not low enough to displace existing energy infrastructure, Nocera says.
“It’s still not good enough, because we have fracking,” he says. “Until you put a price on carbon, none of these technologies are going to get a foothold,” Nocera says.
In the context of Shell arguing (h/t Dan O.) that there’s no escape without CCS, it looks like what we are really arguing about is not the sustaining or abandonment of modern civilization, but the persistence of the business model of a few powerful corporations and their numerous satellite industries.