Massachusetts Institute of Technology professor Daniel Nocera is a "huge centralised energy person", but when he looks at the world's energy challenges, he thinks the key is to make energy generation cheap and distributed.
MIT last year announced that a technology developed by Nocera's lab — a catalyst that can split water — could be used store solar energy. Earlier this year, Nocera formed a company called Sun Catalytix, backed by venture-capital firm Polaris Ventures, to commercialise that discovery.
Engineers are now working on a prototype design for the system, Nocera said at the EmTech conference on emerging technology on 24 September. He added that the company has also hired Art Goldstein, the retired chief executive of water desalination company Ionics, which was purchased by General Electric, to be chairman.
"This technology is moving really fast. We're already at the engineering prototype design. I'm hiring no scientists — I'm just having a massive engineering effort right now," he said. "Within two years, we want to have a totally working kilowatt system."
However, a fully functioning system will take more like eight or 10 years because it requires multiple components, including hydrogen storage, cheaper solar panels and cheaper fuel cells.
Shooting for the moon
The team at Sun Catalytix is pursuing a technology and commercial breakthrough — not an incremental improvement to solar technologies, as fellow MIT spin-off 1366 Technologies is doing.
The core of Sun Catalytix's technology is a cobalt phosphate catalyst that is more efficient at splitting water into hydrogen and oxygen than other materials, according to Nocera. During his talk, he said that it will work under ambient temperatures and with a wide range of water quality — the lab has tested water from the Charles River in Boston and it operates well.
There are already commercial electrolysers that split water to make hydrogen, but they are expensive and require a significant amount of energy to run. Sun Catalytix is testing an electrolyser, built around the catalyst, that can be manufactured using cheap PVC plastic, Nocera said.
The idea is to use solar panels to power the electrolyser to produce hydrogen which would be stored in tanks. When people need electricity, the stored hydrogen would put through a fuel cell.
Nocera calculates that three litres of water a day could power a home, or a fuel cell car in the "legacy world", or rich countries with a high standard of living. In poor countries where people do not use much energy, three litres would make a dramatic difference, providing power for several people, he said.
Billions of people in countries of Africa or in India use little energy today, but that is changing rapidly. So even if richer countries use energy efficiency, the world's energy needs will continue to explode in the coming decades, making cheap, distributed energy essential, he said.
"The solution, assuming the legacy world does the right thing [and uses energy efficiently], to this problem for the future is attacking the non-legacy world and they don't have any money. That's the challenge," he said.
Typically what happens in energy research is that engineers try to shrink large-scale systems down, but that approach does not work because the costs of manufacturing do not go down enough, Nocera argued. Batteries, in his view, do not have sufficient energy density to be cheap enough for storage on a wide scale, while fuel cells offer more promise.
"What you need in my opinion is to start with a blank piece of paper and start inventing. Don't take what's there and try to re-engineer it."
For Sun Catalytix's vision to take hold, however, it needs more than a cheap electrolyser. Also required is a hydrogen storage tank, which is not a big technical or commercial challenge. A cheap a hydrogen fuel cell still needs more work but is attainable.
"I don't need a fuel cell that's in a Toyota or Honda car. I need all the technology they threw away 20 years ago because they couldn't get high enough power density for a car," he said.
Similarly, relatively inefficient amorphous silicon solar panels need to be cheaper but would suit the application he envisions a distributed power source for poor countries.
"We have to get away from how we think about how we live in the legacy world [because] that will not be the solution for the non-legacy world," he said.
