ANU researchers set new solar-to-hydrogen efficiency record

Tuesday 21 July 2020 10am

Researchers at The Australian National University (ANU) have achieved a new efficiency record for hydrogen cells that can convert water into hydrogen simply using sunlight.

Lead author Dr Siva Karuturi says hydrogen has an important role to play in solving the intermittency of renewable energy sources.

 "There are significant cost benefits to this solar-to-hydrogen approach as it eliminates the need for added infrastructure that's necessary when hydrogen is produced using an electrolyser."

Previous methods of converting water to hydrogen have had a low overall energy conversion efficiency but Dr Karuturi's research has improved this.

"To produce hydrogen in the past, solar plants had to produce electricity which is then used to electrolyse water to produce hydrogen. This new method is more direct, making it more efficient," he said.

The unique approach outlined in the ANU study also used inexpensive semiconductor materials and resulted in a 17.6 per cent solar-to-hydrogen efficiency.

This is nearing the efficiency of solar panels being installed on rooftops, which have an efficiency of around 20 per cent.

Dr Karuturi says that they are working towards reaching an efficiency of 20 per cent in the coming months, which will pave way for low-cost green hydrogen production.

The research team used a "tandem" light absorber structure- placing a perovskite cell on top of a specially-made Si electrode.

Co-author Dr Heping Shen, who develops perovskite cells, says with extraordinary optoelectronic properties, the perovskite materials offer great potential for low-cost, high-efficiency tandem devices with Si.

"Together with unprecedented progress in efficiency, the perovskite material has also undergone significant improvement for its stability, making it one of the most attractive candidates for the solar industry," Dr Shen said.

This new method makes use of noble-metal catalysts such as platinum and Dr Karuturi says that they are working to replace them with cheap materials to further reduce costs in the future.

Another major outcome for the research is that Australia will more efficiently be able to export hydrogen.

Dr Karuturi noted that last year the Council of Australian Governments (COAG) Energy Council approved a national hydrogen strategy which aims to enable a hydrogen economy.

"This strategy is important to Australia and our hope is that this new, direct method of converting water to hydrogen can aid these efforts," said Dr Karuturi.

The research has been published in Advanced Energy Materials.


Dr Siva Karuturi
T: (02)61250355

Related news stories

Green hydrogen gets a boost from a thin layer of foil

A thin layer of metal foil could be the key to making green hydrogen production from solar energy a commercial reality. A team led by scientists at the ANU Research School of Physics used nickel-based foils to create robust, cheap and efficient water splitting cells driven by solar energy. “This...

Clever design puts cheap green hydrogen within reach

A series of clever design tweaks have boosted the efficiency of solar-powered hydrogen production, using cheap and readily available materials. After COVID, hailstorms and bushfire smoke disrupted plans to develop entirely new solar components, the team from ANU Research School of Physics and ANU College...

Nanoflowers help to grow the hydrogen economy.

In the search for optimum hydrogen production researchers have found decorating their electrodes with tiny metal flowers boosts the process significantly. Dr Asim Riaz said the structures not only enabled efficient electrolysis (splitting water into hydrogen and oxygen) but cost of producing electrodes...

New silicon promises sunnier days for solar tech

An international research team led by The Australian National University (ANU) has made a new type of silicon that better uses sunlight and promises to cut the cost of solar technology. The researchers say their world-first invention could help reduce the costs of renewable electricity below...