UNLV Uses Sunlight to Make Hydrogen from Water

DN Staff

June 22, 2008

2 Min Read
UNLV Uses Sunlight to Make Hydrogen from Water

While traveling through the Southwest, I made a stop at the University of Nevada, Las Vegas (UNLV) to visit some colleagues and get a peek at the energy-related research on going at the university’s Energy Research Center.

 

UNLV’s Department of Mechanical Engineering capitalizes impressively on Southern Nevada’s abundant sunlight by conducting research on several different aspects of solar energy. One leader I met in this area was Dr. Robert F. Boehm. As director of the Energy Research Center, Dr. Boehm oversees UNLV’s Solar Energy Laboratory. The Solar Energy Lab boasts a utility-scale heliostat which can hold up to 25 kW of experimental solar modules. While I was visiting the installation, researchers and engineers were installing new modules from Amonix that I was told were experimental triple-junction photovoltaic cells. No photographs were allowed.

 

I also had the opportunity to meet with Dr. Jianhu Nie and Dr. Suresh Sadineni, UNLV research faculty in the Energy Research Center. These faculty are performing work in collaboration with Hydrogen Solar to generate hydrogen gas from water using sunlight. Billed by UNLV as “an advanced method of generating hydrogen,” this scheme allows water to absorb energy directly from sunlight, breaking the liquid into its consistent elements. It was explained to me that solar photons do not have quite enough energy to perform this separation on their own (otherwise all liquid water on the planet would disassociate under direct sunlight). So, catalysts lower the reaction barrier while an embedded solar panel provides the extra energy needed to move the reaction forward, generating hydrogen and oxygen gas.

 

To me, the hydrogen-solar research ongoing at UNLV is crucial if the hydrogen economy is to ever become a reality. At the moment, hydrogen is often generated by stripping atoms from carbon-based fossil fuels using steam reforming and the water-gas shift reaction. This approach is problematic for two reasons. First, after stripping hydrogen from fossil fuel, carbon remains and must be disposed of. So, hydrogen produced from fossil fuels has potential global climate change ramifications. Second, the energy content of the resulting hydrogen is less than the energy content of the original fossil fuel. So, the user would have been better off, from a total energy standpoint, just burning the fossil fuel.

 

Challenges with conventional water electrolysis include low efficiency and undesirable byproducts resulting from gasifying ions that must be dissolved in the water to create an electrochemical circuit. For example, chlorine gas is a byproduct of brine electrolysis. The UNLV solution sidesteps these problems, making hydrogen production from purer water at higher efficiency possible. I applaud this effort as well as the other renewable energy research ongoing at UNLV.

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