Solar-powered hydrogen production with improved efficiency

December 22, 2015, Japan Society of Applied Physics
Solar-powered hydrogen production with improved efficiency
Researchers in Japan have developed an efficient way of splitting water to produce hydrogen using energy from the sun. Their technique uses a combination of concentrated photovoltaic modules with electrochemical cells, and achieves a hydrogen production efficiency of 24.4%, the highest solar-to-hydrogen efficiency yet recorded.

Hydrogen could potentially provide a readily available, clean form of energy derived from solar power. To achieve this, scientists need to find a highly efficient, low-cost way of splitting water into its constituent parts of oxygen and hydrogen using the energy from the sun.

Now, Masakazu Sugiyama, Katsushi Fujii and colleagues at the University of Tokyo, together with co-workers at the University of Miyazaki, Japan, have found a way to produce at the highest yet, using a combination of concentrator photovoltaic (CPV) modules and electrochemical (EC) cells.

CPV technology generates electricity by using mirrors or lenses to focus an intense beam of sunlight onto tiny but highly efficient solar cells. The researchers used the most efficient CPV modules currently available, with an efficiency of around 31%. They used a InGaP/GaAs/Ge three-junction solar cell at the sunlight focus point inside the CPV. The EC cells, which provide the means for , were then connected in series to the CPV modules using copper wires.

The team placed their combined device outdoors, and fed pure water into the EC cells. They found that their device was able to produce hydrogen at an efficiency of 24.4% – the highest level of solar-to-hydrogen efficiency yet achieved. Sugiyama and Fujii believe the direct connection between the high efficiency CPV modules and EC cells optimized the transfer from sunlight to hydrogen, and that further improvements of both components and their connecting parts will enhance the efficiency still further.

The team are convinced that combining CPV modules with EC cells in this way is a realistic method of generating renewable hydrogen.

Explore further: A novel solar CPV/CSP hybrid system proposed

More information: Akihiro Nakamura et al. A 24.4% solar to hydrogen energy conversion efficiency by combining concentrator photovoltaic modules and electrochemical cells, Applied Physics Express (2015). DOI: 10.7567/APEX.8.107101

Related Stories

A novel solar CPV/CSP hybrid system proposed

February 11, 2015

In concentrating photovoltaic (CPV) systems only a small part of the incident solar energy can be converted into electricity and the majority of the incident energy is dissipated as waste heat. Although the waste heat could ...

Minuscule pillars double the efficiency of solar cells

December 8, 2015

Solar cells are generally flat. However, by adding minuscule silicon pillars to the surface, it is possible to more than double the amount of energy produced for each surface. This has been demonstrated by research by academics ...

World record solar cell with 44.7% efficiency

September 24, 2013

German Fraunhofer Institute for Solar Energy Systems, Soitec, CEA-Leti and the Helmholtz Center Berlin announced today that they have achieved a new world record for the conversion of sunlight into electricity using a new ...

Recommended for you

What do you get when you cross an airplane with a submarine?

February 15, 2018

Researchers from North Carolina State University have developed the first unmanned, fixed-wing aircraft that is capable of traveling both through the air and under the water – transitioning repeatedly between sky and sea. ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.