The brilliant folks over at MIT have just announced a ‘major discovery’ that could open the door for the solar power revolution: power at night! Using a catalyst consisting of cobalt metal, phosphate, and an electrode, Daniel G. Nocera and his team of MIT researchers, have created a simple and efficient method to split water molecules and produce oxygen gas and hydrogen—thereby overcoming one of the major obstacles to widespread solar adoption: energy storage when the sun doesn’t shine.
Traditionally, solar power that is not directly used upon collection is stored in largely inefficient chemical battery banks. This method has proven to be costly, wasteful, and potentially environmentally hazardous. However, Nocera’s efficient method for splitting water molecules allows solar systems to store excess energy as hydrogen, which can be used in a fuel cell generator at night or on cloudy days.
From the MIT announcement:
Inspired by the photosynthesis performed by plants, Nocera and Matthew Kanan, a postdoctoral fellow in Nocera’s lab, have developed an unprecedented process that will allow the sun’s energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.
The key component in Nocera and Kanan’s new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity – whether from a photovoltaic cell, a wind turbine or any other source – runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.
Combined with another catalyst, such as platinum, that can produce hydrogen gas from water, the system can duplicate the water splitting reaction that occurs during photosynthesis.
The new catalyst works at room temperature, in neutral pH water, and it’s easy to set up, Nocera said. “That’s why I know this is going to work. It’s so easy to implement,” he said.
Currently available electrolyzers, which split water with electricity and are often used industrially, are not suited for artificial photosynthesis because they are very expensive and require a highly basic (non-benign) environment that has little to do with the conditions under which photosynthesis operates.
More engineering work needs to be done to integrate the new scientific discovery into existing photovoltaic systems, but Nocera said he is confident that such systems will become a reality.
“This is just the beginning,” said Nocera, principal investigator for the Solar Revolution Project funded by the Chesonis Family Foundation and co-director of the Eni-MIT Solar Frontiers Center. “The scientific community is really going to run with this.”
Nocera hopes that within 10 years, homeowners will be able to power their homes in daylight through photovoltaic cells, while using excess solar energy to produce hydrogen and oxygen to power their own household fuel cell. Electricity-by-wire from a central source could be a thing of the past.
This breakthrough accomplishes a few things:
- Makes fuel-cells viable due to easy on-site hydrogen production. (Replaces current electrolysis methods.)
- Replaces oil as the leading cheap energy source.
- Decentralizes power generation.
- On-location power production recaptures electricity lost due to inefficiencies in power distribution (powerlines).
- (Potentially) Removes energy companies from global power.
Here’s a video of Nocera.