On July 30, 2013 I had talked about TU Delft and HZB creating solar-hydrogen breakthrough technology. Well, it seems like there is no shortage of solar-hydrogen breakthroughs recently as the University of Colorado, Boulder has created one as well.
Researchers at the University of Colorado, Boulder (CU-Boulder) have come at the issue from a completely different angle using a solar-thermal system with a huge mirror array that focus sunlight onto a tower.
According to CU-Boulder, “The CU-Boulder team has devised a solar-thermal system in which sunlight could be concentrated by a vast array of mirrors onto a single point atop a central tower up to several hundred feet tall. The tower would gather heat generated by the mirror system to roughly 2,500 degrees Fahrenheit (1,350 Celsius), then deliver it into a reactor containing chemical compounds known as metal oxides, said CU-Boulder Professor Alan Weimer, research group leader.
“As a metal oxide compound heats up, it releases oxygen atoms, changing its material composition and causing the newly formed compound to seek out new oxygen atoms, said Weimer. The team showed that the addition of steam to the system — which could be produced by boiling water in the reactor with the concentrated sunlight beamed to the tower — would cause oxygen from the water molecules to adhere to the surface of the metal oxide, freeing up hydrogen molecules for collection as hydrogen gas.”
So, in essence, the metal oxide compound acts like a giant sponge that soaks up the oxygen atoms in the steam and lets the hydrogen atoms pass through to a container. The above photo is an artist’s conception of a commercial solar-hydrogen production plant based upon this technology.
The technology to focus sun rays for higher temperature reactions was developed in Israel and started working 4 years ago in a kibbutz providing heating and electricity that is competitive . Common knowledge as results were published at the time. They used PV cells running at 300C
For Oxide stripping and they have a coal bed/sunlight technology to get to 1200C