One of the most abundant and amazing processes on earth could be used to provide massive amounts of electricity someday. Plants evolved the masterful and elegant process of photosynthesis millions of years ago. If humans could duplicate the photosynthesis power contained in only an hour’s worth of direct sunlight, photosynthesis power could take over from fossil fuels and do the job much more efficiently.  Read more about Developing a Hydrogen Economy: Challenges and Potential

Scientists from Imperial College London have received a grant of £1million to learn enough about photosynthesis to be able to mimic it artificially. In plants, photosynthesis involves absorbing sunlight and using it to change carbon dioxide and water into sugar. It is easily the most elegant way of converting sunlight to energy. Researchers have calculated that if artificial photosynthesis could capture only 10% of the sunlight that reaches artificial “leaves,” coverage of only 0.16% of the surface of the world could provide enough electricity to meet global energy demand.

The difference between artificial photosynthesis power and the kind that plants use is that artificial leaves would retain and store the hydrogen captured to be used as an energy source. In real plants, hydrogen is released as a byproduct of photosynthesis. We already know how amazing photosynthesis is as far as fueling living things: after all, photosynthesis already provides energy directly or indirectly to every living thing on earth. Ultimately the only truly sustainable energy source is the sun, and scientists are just now seriously considering ways to harness that energy, not only by using new materials in traditional solar energy panels, but also in creating energy through photosynthesis power.

The London research team wants to build artificial photosynthesis power plants that can split water molecules and create fuels like hydrogen and methanol. These could either make electricity or they could be used to power clean transportation. In the Netherlands, the government has set aside €40million for research into photosynthesis power, and the US is expected to spend around $35 million a year on projects that attempt to create fuels from sunlight.

Artificial leaves, unlike the real things, would not be able to remove carbon dioxide from the air, but hydrogen and methanol are considered “clean burning” fuels. Basically the artificial photosynthesis power would begin with sunlight being used to split water into hydrogen and oxygen. A limitless supply of hydrogen could be the ultimate end product of artificial photosynthesis power.

If the technology were used small scale, an artificial leaf that could split a relatively small amount of water – perhaps a few liters – per day into hydrogen and oxygen, it would be enough to power an entire household for a day. While researchers are already able to split water, the process is difficult and involves harsh chemicals used in precisely modified environments. Making the hydrogen splitting process affordable is the key to harnessing photosynthesis power.