Two researchers from the University of Delaware, Erik Koepf and Michael Giuliano spent a couple of months in Switzerland working on a novel sunlight-driven water-splitting device. The initial tests proved that solar fuel (aka hydrogen) could be produced using sunlight, mirrors (no smoke), a reactant and water.
According to the University of Delaware, “Koepf’s reactor is designed to accomplish the first step in a two-step water-splitting process to generate hydrogen renewably from sunlight. The reactor, which is closed to the atmosphere, uses gravity to feed zinc oxide powder (the reactant) into the system through hoppers that dispense the powder onto a ceramic surface. There it undergoes a thermochemical reaction upon exposure to highly concentrated sunlight within the reaction cavity, producing solar fuel.”
The initial tests were conducted on a small-scale mirror and system, producing a modest amount of hydrogen, yet proving the system does work. Koepf and Giuliano now want to scale up the solar reactor and produce as much hydrogen as possible. The only problem is that they needed a mirror four times the size of the one currently on hand and none exists. So they had to build one plus scale up the system as well.
Karen B. Roberts of the University of Delaware reports, “The mirror is a perfectly flat, water-cooled aluminum plate with a 98 percent reflective foil surface. About one-inch thick, the mirror measures 45 by 45 inches square and contains 13 holes bored through the one-inch thick plate along one of the mirror’s axes, enabling water to continuously pass through the channels and cool the mirror’s surface when in use.
“To allow for precise adjustments in real time, the mirror is suspended above the reactor by threaded rods connected to a motor and control assembly, and controlled using a joystick. Placed on a 45 degree angle, Koepf explained, it will enable a perfectly reflected, concentrated light cone that is free of distortion to enter the reactor.”
The 10-foot mirror and 3,000 system have already been shipped to Switzerland. And with any luck weeks from now, this Swiss reactor will run like a clock.