The world receives enough sunshine to supply all of its energy requirements, making the prospect of inexpensive fuel to run machines, automobiles, and large-scale businesses attractive.
This month, a research team led by the University of Tokyo received a €5 million prize from the European Union for developing a revolutionary strategy for producing abundant and affordable fuel from sunshine.
The EU competition sought to stimulate worldwide collaboration over the most potential clean-energy routes while accelerating the development of artificial photosynthesis, one of the most promising emerging technologies in the race to find fossil fuel substitutes.
Big potential
The technology mimics natural photosynthesis in which plants use rays from the sun to transform water into oxygen and carbon dioxide into chemical energy in the form of glucose.
Artificial photosynthesis uses sunlight to split water into oxygen and hydrogen. Oxygen is released into the atmosphere and hydrogen can be used as fuel.
‘Artificial photosynthesis has the potential to provide a huge amount of green fuel,’ Professor Kazunari Domen, the winning team’s coordinator, said in an interview after the European Commission announced the award on 5 December in Brussels.
Composed of scientists from the University of Tokyo and Japanese energy company INPEX, the team was among 22 applicants for the Fuel from the Sun prize and made it onto a shortlist of three finalists before emerging victorious. The two runners-up were from France and Britain.
The contest took place in the framework of a global initiative called Mission Innovation which brings together 24 countries and is spurring research activities and investments in a bid to make clean energy universally accessible and affordable.
‘The prize was awarded to the winning team for the high degree of professional engineering and integration,’ said the Commission.
If artificial photosynthesis can be done cheaply enough, it could replace oil, natural gas, and coal for all sorts of vehicles, machines, and industries including chemicals that cannot be powered by renewable electricity alone.
Although sunlight is abundant and free, many of the methods for converting it into fuel are too expensive – or too difficult to scale up – to compete with fossil fuels.
Engine test
The winners’ prototype has the potential to be both cheap and easily scalable.
Contestants had to develop a device that used artificial photosynthesis to create enough fuel to power a small engine. The devices were run outdoors and tested for the amount of fuel they produced, their composition, and their ability to power the engine.
The winning system used photocatalysts in contact with pure water.
Photocatalysts are ultrafine particles that absorb the sun’s energy and trigger the water to split. The resulting hydrogen was then combined with carbon dioxide to produce methane, which was used to run the engine.
Because photocatalysts are a simple way to convert sunlight into chemical energy, they hold out the hope of making low-cost green hydrogen, said Prof. Domen, a professor at the University of Tokyo and Shinshu University.
Green Hydrogen
The challenge of the contest was to build a fully functional prototype of an artificial photosynthesis-based system that could produce usable synthetic fuel.
‘Our project has so far targeted the production of hydrogen, but thanks to this competition we gained important insights into the synthesis of green fuels like methane that are more favorable for storage and transport,’ Prof Domen said.
The hydrogen produced in the winning system can be deemed green, he said.
Today green hydrogen, made with renewable energy including solar and wind, accounts for less than 1% of total hydrogen produced, according to the International Energy Agency.
The current cost of producing green hydrogen is so high that the activity is unprofitable without government support, according to Prof. Domen.
His team’s priority now is to find a more effective photocatalyst.
The winning device achieved about 0.6% efficiency – meaning that around 99% of the energy was lost. To make such a fuel commercially viable, the catalyst would need to deliver at least 5% efficiency, said Prof. Domen.
‘We have already found several candidate materials which can deliver efficiency of 5% or even 10%,’ he said. ‘So I believe that we can do that shortly.’
Market hurdles
If successful, the team should be able to overcome the remaining barriers to commercialization within years – rather than decades – in collaboration with industry partners, he said.
One hurdle that Prof. Domen is confident of clearing is regulatory.
While the combination of hydrogen and oxygen is ‘explosive’, he said, ‘we know how to handle the mixture safely.’
Another obstacle is developing cheap reactors and improving the separation of hydrogen from the mix.
If successful, the final production plants will comprise very thin containers of water and photocatalysts, which are exposed to sunlight.
About 10 000 plants, each covering 25 square kilometers, would need to be built by 2050 to meet one-third of the world’s energy needs, according to Prof Domen.
profit potential
‘Many industry people told me that if they can make money, then 10 000 plants is not impossible,’ he said. ‘It depends on whether they can make money or not.’
Meanwhile, as his team races to find a more effective photocatalyst, Prof. Domen says the Fuel from the Sun prize will help turn skeptics of the method into proponents of it.
‘Most people don’t believe photocatalysts would work,’ he said.
This article was originally published in Horizonte EU Research and Innovation Magazine.
FUEL FROM THE SUN FINALISTS
The two runners-up for the “Fuel from the Sun” prize were the France-based Atomic Energy and Alternative Energies Commission, also known as CEA, and the University of Cambridge in the UK.
The following are * made by representatives of two contestants at the 5 December award ceremony:
cea
‘We are very happy to have been a part of this very exciting project related to the environmental crisis.’
‘I would like to congratulate the other contestants and, of course, the winner of the prize. We are impatient to discover more about the technology you developed and we are, of course, open to collaboration. And we have young researchers that are open to opportunities in these topics too.
University of Cambridge
‘It pushed us to develop these technologies much faster than we would have done otherwise.’
‘Many congratulations to the Japanese team, a very well-deserved winner. We have all been following their work for many, many years – it’s very impressive. But also many congratulations to the French team. We are very pleased to have been in the boat with you and battle for the prize.
Subscribe to AFK Free Media on Google News.
