German researchers have developed what they claim is the first artificial photosynthesis hydrogen generator to be compact and of a reasonable size for practical applications.
The device, described in the journal Nature Communications, is 64cm square in size and splits water into hydrogen and oxygen with 3.9 per cent efficiency. That is actually 2.9 per cent more than what natural photosynthesis achieves.
"Naturally this is only the first draft for a complete facility,” said Bugra Turan from the Forschungszentrum Juelich, who developed the technology together with his colleague Jan-Philipp Becker. “There's still plenty of room for improvement."
The device is made entirely from low-cost and readily available materials. It consists of several solar cells connected to each other by a special laser technique. "This series connection means that each unit reaches the voltage of 1.8V necessary for hydrogen production," explained Becker. "This method permits greater efficiency in contrast to the concepts usually applied in laboratory experiments for scaling up."
By combining a larger number of such units, researchers in future could build an entire artificial photosynthesis energy-generating facility.
"To date, photoelectrochemical water splitting has only ever been tested on a laboratory scale," Turan said. "The individual components and materials have been improved, but nobody has actually tried to achieve a real application."
The researchers hope to increase the efficiency of the technology to 10 per cent. After that, they will work towards launching the technology commercially. Currently, the device is built using conventional solar cells but the researchers are already looking into the possibility to use novel perovskite cells, which could improve efficiency up to 14 per cent.
"This is one of the big advantages of the new design, which enables the two main components to be optimised separately: the photovoltaic part that produces electricity from solar energy and the electrochemical part that uses this electricity for water splitting," said Becker.
Photosynthesis-inspired technologies could help solve the problem of renewable intermittency in future. The rise of renewable power generation technologies such as wind and solar is putting strain on electricity grids. Storage technologies are needed to help the grids handle the sometimes excessive electricity generation.
Using solar power to split water into hydrogen and oxygen could help solve this problem in future as hydrogen is another source of clean energy that could be used whenever needed.
This process was first investigated in the 1970s, but has only begun to attract increasing attention in recent years.