Harvard professor Daniel Nocera has his eyes on six billion people’s energy needs. That’s the six billion who live in developing countries and make up the vast majority of the world’s population. But the developing world, he says, isn’t about to make the same mistakes as richer nations.
“What I’m banking on is that the developing world is going to take their money and take a different path,” he says. Nocera believes countries will opt for lots of smaller grids supplying towns and villages with electricity from solar panels or biomass generators, regardless of whether they are connected to a national energy grid in the end or not.
Nocera is a chemist by trade, but his career really took off when he developed his artificial leaf – an experimental technology that can turn water into hydrogen and oxygen using just sunlight and some catalysts. The resulting gases can, of course, be burned in a fuel cell to generate electricity.
Trying to bring revolutionary energy technology to poorer countries has two main challenges. First of all, energy startups aren’t always popular with venture capitalists looking for a quick return and, secondly, Nocera says, “Nobody can get rich off of poor people”.
There’s also the problem of having to introduce fuel cells to developing markets, a stumbling block in itself. Which is why Nocera went back to the drawing board and came up with a new version of his artificial leaf, which he calls the “bionic leaf”, and which creates bio-fuel that is easier to burn.
It does this with the help of synthetically engineered bacteria. A small rectangle suspended in water is coated with catalysts on either side that uses energy from the sun to dislodge electrons from the H2O molecules, splitting them. As before, this releases hydrogen and oxygen. But this time the hydrogen is consumed by the bacteria which combine it with carbon dioxide from the atmosphere. Their resulting excretions are “liquid fuel”, Nocera explains.
He’s now working with the Indian Institute of Chemical Technology to develop more prototypes and attract investment from local firms who may want to commercialise the system. “If I don’t get a prototype in two years at a pretty large scale, I’ll be pretty disappointed,” he says.
One of the advantages of the technology is that it can split hydrogen and oxygen from practically any water source – it doesn’t have to be pure. His team has even tried to do it with simulated urine samples developed by Nasa. And, remarkably, it worked. “I’m sure some of my students tried to split gin,” he says. “God knows what they tried splitting in my lab with the artificial leaf.”
When it became clear that commercialising the prototype was not going to be easy, Nocera’s former firm Sun Catalytix switched to producing flow batteries. In these, chemical energy flows between two liquid-filled compartments separated by a membrane. Sun Catalytix was later bought by Lockheed Martin and Nocera believes the batteries will soon be used to store electricity generated by renewables during the day, for example, so that it can power buildings at night.
But despite the high profile of his work, Nocera admits he is a divisive figure in scientific circles. “[Some] don’t like me calling out the academic community, saying they’re greedy and that when they make inventions the first thing [they think of] is how much money they can make.” But he says he has a significant public following who, he argues, are tired of being told the future is bleak. “They’re thirsty for people with solutions because they’ve heard for so long how bad it’s going to be,” he says. “That feistiness… that’s certainly helped me with the public.”