MIT researchers have discovered a fairly cheap and easy way to store solar power so it can be utilized when the sun is not shining – a development they claim will make solar power a mainstream energy source within the next decade. Until now, one of the major hurdles to solar energy’s commercialization is that current energy storage methods are prohibitively expensive and inefficient. Now, however, Daniel Nocera a professor of chemistry at MIT, reported in Science magazine that a team he is leading has developed an unprecedented electrolysis process that uses the sun’s energy to split water molecules into oxygen and hydrogen gases. The gases can then be stored and later run through a fuel cell to produce electricity as needed.
Key to the process is a newly developed catalyst that produces oxygen gas from water. Inexpensive and easy to make, the catalyst consists of cobalt metal, phosphate and an anode, placed in water. When electricity – from a photovoltaic cell or any electrical source – is run through the catalyst, the cobalt and phosphate form a thin film on the electrode’s surface, creating oxygen gas. When combined with a cathode capable of producing hydrogen gas from water, the two electrodes create a system that mimics the way plants use sunlight to split water and create energy during photosynthesis.
“The new catalyst works at room temperature, in neutral pH water, and it’s easy to implement,” Nocera says. “That’s why I know this is going to work.”
While wind turbines or other energy sources could also be coupled with the same storage system, Nocera believes sunlight has the greatest potential of any power source to solve the world’s energy problems. In one hour, he claims, enough sunlight strikes the earth to provide the entire planet’s energy needs for one year. Researchers envision a future where sunlight could be used to generate hydrogen and oxygen from seawater. The gases would be piped to industrial-scale fuel cells for conversion to electricity and fresh water.
Nocera says more engineering would be required to integrate his discovery with existing photovoltaic systems. He will tackle this task during the upcoming semester. His work is being funded by the National Science Foundation and the Chesonis Family Foundation, which recently gave MIT $10 million to explore solar alternatives to fossil fuels. As for the significance of Nocera’s findings, Karsten Meyer of Germany’s Friedrich Alexander University, who was uninvolved in the research, says, “For solar power, this is probably the most important single discovery of the century.” James Barber of Imperial College London, echoed those sentiments. “This is a major discovery with enormous implications for the future prosperity of humankind,” Barber says, calling the breakthrough a “giant leap” toward generating clean, carbon-free energy on a massive scale.