Sunlight Into Hydrogen: It Works If You Concentrate

A novel design might be the next big breakthrough in the pursuit of hydrogen from clean sources. University of Delaware doctoral student Erik Koepf’s self-sustaining solar reactor uses mirrors to concentrate sunlight—enough to reach a sizzling 3,000 degrees Fahrenheit.

“This is probably the most complex device built by a graduate student in the history of our department,” Ajay Prasad, one of Erik’s advisors, says in a university statement.

solar reactor, hydrogen fuel cell

image via University of Delaware

The cylindrical reactor, about 2 feet by 3 feet, weighs 1,750 pounds and contains layers of insulation and ceramic materials. When heated, hoppers feed the reactant, zinc oxide powder, into the system where it is transformed to pure zinc vapor. The zinc vapor is then reacted with water to form solar hydrogen. Cooling blocks are strategically placed within the reactor to keep motors, a quartz window and the aperture ring at suitable temperatures.

The new solar reactor is undergoing testing now at the Swiss Federal Institute of Technology in Zurich. “Essentially, we take zinc oxide powder and thermochemically store the energy of the sun in it, then bottle it up,” explains Koepf, who won the Laird Fellowship Award because of his passion for environmental awareness, education and outreach. The $22,000 award is given annually to an up-and-coming graduate student in engineering to encourage broad intellectual pursuits.

The next step is finding out whether this new design is reliable and efficient. With successful test results, the prototype could be scaled up to produce hydrogen for fuel at an industrial level. The model has not been tested outside of the lab until now, so no one knows just how much fuel it will produce.

Based in New York City, Leah Jones is a freelance writer with undergraduate degrees in criminal justice and forensic science. She has worked on research in the toxicology field for several years, and she brings her passion for science into the realm of green technology with EarthTechling. Leah has studied English at the graduate level and has authored or co-authored over 30 publications in scientific journals. When she's not writing, Leah enjoys playing music with her husband and teaching music to New York City kids.

1 Comment

  • Reply May 4, 2012


    Fascinating technological solar energy amplification breakthrough!  Hopefully we can find applications other than hydrogen production.

    Hydrogen production requires inputs to create hydrogen.  Unfortunately, one of the main inputs is water.  I propose that we consider the following key challenges regarding the production of hydrogen, in the middle of the desert, into a form that can be used as an alternative fuel:

    Challenge #1:  Water is typically in short supply in the desert.

    Challenge #2: There are concerns that water scarcity will become the next big global crisis.  Unless these desert installations also include desalinization plants, the undertaking would be using potable water and become as contentious as turning food crop into fuel only worse i.e. turning potable water into fuel in the midst of a global water shortage.

    Challenge #3: So now we have this hydrogen fuel manufacturing facility out in the middle of the desert, which will require vast amounts of fuel (traditional) to ship water (heavy) from where it ‘grows’, followed by a further need for fuel to ship the hydrogen to storage facilities near urban centres where it would be consumed.

    So, while fantastic in the realm of scientific research, undertakings involving hydrogen production seem entirely impractical in reality. In fact, more than just impractical; aside from the contentious use of water, appropriate life-cycle analysis may show that the amount of fuel required to support the logistical aspects of a hydrogen fuel industry, exceeds the amount of fuel produced.

    I propose that systems engineers be brought into the midst of the scientific community to thoroughly evaluate the practicality.  I know that we all like to invent exciting new technologies and that during these challenging economic times even the universities are being pressured to bring innovations to the table that can be commercialised.  I’m just suggesting that lifecycle analysis needs to be conducted beforing charging full speed ahead.

    But don’t give up … 🙂

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