‘Bionic leaves’ that can turn sunlight into liquid fuel could drastically reduce the need for large plantations to grow biofuel crops, while combating climate change.
Harvard University researchers working on the project, dubbed ‘bionic leaf 2.0’, believe it could help to protect food supplies and local people's land rights.
The technology uses solar panels to split water molecules into oxygen and hydrogen, with the hydrogen being separated off and moved into a chamber where it is consumed by bacteria.
With the addition of a special metal catalyst and carbon dioxide, the process generates liquid fuel.
The method is described as an artificial version of the photosynthesis process plants use to make energy from sunlight, water and carbon dioxide.
If it becomes economically viable, the technology could replace oil wells or plantations where food crops are grown for fuel, the study's lead author claimed.
"This [new energy source] is not competing with food for agricultural land," said Harvard professor of energy Daniel Nocera.
"This is a true artificial photosynthesis system. Before, people were using artificial photosynthesis for water-splitting, but this is a true a-to-z system, and we've gone well over the efficiency of photosynthesis in nature."
Crops such as corn and sugar cane have been increasingly cultivated to produce biofuels. About four per cent of the world's farmland is used to grow crops for fuel rather than food.
Tens of thousands of small-scale farmers across Africa, Asia and Latin America have been displaced by plantations growing crops to make biofuels, according to GRAIN, a Barcelona-based land rights group.
The new technology could help protect their land rights while also reducing the greenhouse gas emissions that are warming the planet, Nocera said.
"The [land] footprint these solar panels need is about one-tenth the size of what you would need for sugar cane," he said.
He suggested that if governments put a price on carbon-dioxide emissions, the bionic leaf would appeal to investors as a cost-effective alternative energy source.
A carbon tax boosting US gas prices to European levels, although not yet on the cards, would likely be enough to spur investment in the new technology, he said.
Bionic leaf 2.0 is capable of converting solar energy into liquid fuel with 10 per cent efficiency, significantly higher than the one per cent efficiency seen in the fastest-growing plants that use a similar process.
Earlier this year, Chinese researchers demonstrated another ‘artificial leaf’ that is capable of removing toxic pollutants from waste water.