Welcome back to another installment in PBTS! Today’s news item is a rather interesting one, and it comes to us from the University of Delaware where researcher Erik Koepf has come up with an interest twist on solar power. In most cases, scientists think to use cells that can absorb photons and use them to generate a flow of electrons. But in Koepf’s case, sunlight is used in a different way; namely, as a means of creating alternative fuels.
Basically, the concept for Koepft’s new solar-powered reactor revolves around the idea of getting directly to the hydrogen that is found in conventional fuels, i.e. coal and fossil fuels. While they are decent enough energy sources, they do not burn clean, due to the extensive impurities they carry and by-products they create. If it were possible to remove the essential hydrogen from them, we would have a clean burning and efficient energy supply without the hassle of pollution.
And that’s where the solar reactor comes in. As the name suggests, the reactor relies on the Sun’s energy, which it then uses to split water molecules to get at their hydrogen atoms. This is done by exposing a zinc oxide powder on a ceramic surface to massive amounts of focused sunlight. From there, a thermochemical reaction happens that splits water apart into oxygen and hydrogen.
Though it may sound complicated, the sheer beauty of this concept lies in that fact that it uses the Sun’s infinite energy to do the heavy lifting and accomplish atom smashing. No particle accelerators, no nuclear fusion or fission; and best of all, no pollution! Since the process creates no emissions or Greenhouse gases, this is perhaps one of the most environmentally friendly energy concepts to date.
But of course, the project has some additional requirement which fall under the heading, “additional parts sold separately”. For one, the reactor needs to get seriously hot – between 1750° to 1950° Celsius (3182° to 3542° Fahrenheit) – before it can get to the work of splitting water molecules. For this, a focusing mirror that is roughly 13 square meters, flawlessly flat and 98% reflective is needed.
No much mirror existed when Koepf and Michael Giuliano (his research associate) got started, so they had to develop their own. In addition, that mirror needs to focus the solar energy it collects onto a tiny six centimeter circle that has to be precisely aimed. If the light is just a millimeter or two off to one side, the entire reactor could be damaged. In essence, the system is simple and ingenious, but also temperamental and very fragile.
What’s more, just how efficient it is remains to be seen. While the first tests were successful in creating small amounts of hydrogen, the the real test will take place next month when the duo present their reactor in Zurich, Switzerland, where it will be running at full power for the very first time. Naturally, expectations are high, but it is too soon to tell if this represents the future or a failed attempt at viable alternative power.