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Green energy: the bionic leaf

Will this leaf be the next alternative energy source?

Researchers at Harvard University have developed a bionic leaf that turns sunlight to energy at 10 times the efficiency of natural photosynthesis. What does this mean? Well, the artificial leaf gives us a new alternative energy source to fossil fuel, and could help our (and the wider world’s) quest for greener energy.

  Bionic leaf 2
Better than nature
Natural photosynthesis normally works at a maximum of 1% efficiency, but the bionic leaf produces biomass (energy from living things) from sunlight at around 10%.

Developed by colleagues Daniel Nocera (Patterson Rockwood Professor of Energy) and Pamela Silver (Elliot T. and Onie H. Adams Professor of Biochemistry and Systems Biology), the system uses water, carbon dioxide and energy from sunlight to make energy – just like it does in nature. 

Nocera said: “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.”

Put simply, water-splitting is where water separates into oxygen and hydrogen (via a chemical reaction). The bionic leaf uses solar energy to split water and hydrogen-eating bacteria to make liquid fuel, which can be stored. This is an exciting development because we may be able to use the artificial process to generate green fuel in the future, and it could even be used to help developing countries.
Catalyst for change
It wasn’t all smooth sailing – earlier versions of the leaf used a metal catalyst made from a nickel-molybdenum-zinc alloy, but this produced a type of oxygen that destroyed the biomass-producing bacteria in the system. The researchers had to use high voltages when running the system, which led to a reduced level of efficiency.

The new catalyst, made from a cobalt-phosphorus alloy, meant Nocera could lower the voltage when running the system, making it more efficient for producing the biomass.

“It’s an important discovery — it says we can do better than photosynthesis,” Nocera said. “But I also want to bring this technology to the developing world as well.”

A greener future
This is an achievement that could change the way we power our world - it’s even been suggested that it could be used to power cars.

But there is still plenty of work to do to secure a greener future, especially as fossil fuels are still the main source of energy today. By keeping our home energy efficient, we can help reduce carbon emissions and dependence on fuel sources like gas and oil.

Learn more about carbon emissions and climate change, or find out how boiler cover can ensure your central heating works properly and efficiently around the clock.

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