The authors demonstrate that it is technically feasible to make hydrogen from water, sunlight and a metal oxide. Details are described behind a paywall but here is their
abstract:
Solar thermal water-splitting (STWS) cycles have long been recognized as a desirable means of generating hydrogen gas (H2) from water and sunlight. Two-step, metal oxide–based STWS cycles generate H2 by sequential high-temperature reduction and water reoxidation of a metal oxide. The temperature swings between reduction and oxidation steps long thought necessary for STWS have stifled STWS’s overall efficiency because of thermal and time losses that occur during the frequent heating and cooling of the metal oxide. We show that these temperature swings are unnecessary and that isothermal water splitting (ITWS) at 1350°C using the “hercynite cycle” exhibits H2 production capacity >3 and >12 times that of hercynite and ceria, respectively, per mass of active material when reduced at 1350°C and reoxidized at 1000°C.
Regarding economic feasibility quoting UBC,
Gizmag says this:
"Our objective is to produce hydrogen (H2) at $2/kg H2," Weimer tells Gizmag. "This is equivalent to about US$2/gallon (3.7 L) of gasoline based on mileage in a fuel cell car versus a combustion engine today." The team believes that a site with five 223 m (732 ft) tall towers and about two million sq m (21.5 million sq ft) of heliostats on 485 ha (1,200 acres) of land could generate 100,000 kg (222,460 lb) of hydrogen per day, which is enough to run over 5,000 hydrogen-fuel cell buses daily.
Though the technology has the potential to be a game-changer in pushing the hydrogen economy forward, commercialization might still be several years away thanks to continuing stiff competition from fossil fuels.
UBC says this:
Despite the discovery, the commercialization of such a solar-thermal reactor is likely years away. “With the price of natural gas so low, there is no incentive to burn clean energy,” said Weimer, also the executive director of the Colorado Center for Biorefining and Biofuels, or C2B2. “There would have to be a substantial monetary penalty for putting carbon into the atmosphere, or the price of fossil fuels would have to go way up.”
The US has to decide whether it wants extreme heat induced by global warming or clean fuels.
Nevada scientist
Hanington has found yet another way to make hydrogen:
Researchers at Argonne National Laboratory have discovered certain microorganisms growing in the desert salt flats of our state may allow for the cheap generation of hydrogen gas from only sunlight and saltwater.
A protein found in the membranes of some halobacteria act as a proton pump, effectively capturing light energy and converting it to chemical energy. These tiny creatures, a class of Euryarchaeota, who just love the taste of salt, are responsible for the pink color of brine crystals found along the Humboldt and Carson Sink regions of our state.
Argonne scientist Elena Rozhkova and her colleagues combined a pigment called bacteriorhodopsin with semiconducting titanium nanoparticles to create a reaction that uses sunlight to spark a catalytic process creating hydrogen fuel.
Human history becomes more and more a race between education and catastrophe. H. G. Wells.
Fatih Birol's motto: leave oil before it leaves us.