After ARPA-E, Sun Catalytix Seeks New Funding

The ARPA-E summit this week was flush with startups looking for government grants and VC dollars — and some looking for both. Energy-storage startup Sun Catalytix, which just won $4 million from ARPA-E in January, now plans to seek a new round of venture capital, Sun Catalytix director (and Ethernet inventor) Bob Metcalfe told us in an interview. The Cambridge, Mass.-based startup already has raised $3 million in seed funding and hasn’t yet determined the amount of its Series A round, but Metcalfe said it would be in the “single digit millions” as the ARPA-E contract is helping it keep its capital needs down.
The idea behind the technology, developed by Dan Nocera at the Massachusetts Institute of Technology, is to use an intermittent source of energy, such as solar power, to split water into hydrogen and oxygen via electrolysis. When the energy is needed, the hydrogen and oxygen can either be recombined to produce electricity, such as with a fuel cell, or the hydrogen can potentially be converted into a liquid fuel, like ammonia, and used to power vehicles.

If Sun Catalytix’s energy storage technology is successful, it could help spur the deployment of renewable energy. Solar and wind power are intermittent, meaning that the sun doesn’t always shine and the wind doesn’t always blow, and these events can’t be controlled according to electricity demand. Energy storage has long been considered a Holy Grail for enabling large amounts of distributed renewable-power projects.
But so far, energy storage for these applications has been too expensive. Sun Catalytix hopes to change that and is working with cobalt-phosphate catalysts consisting of compounds in solution, instead of the usual metal surfaces. “The real benefit is that the materials are dirt cheap,” said Metcalfe, who is also a general partner at Sun Catalytix investor Polaris Ventures and the former CEO of defunct biofuel startup GreenFuel Technologies.
Aside from the catalysts, the rest of the device also is made of cheap materials, such as plastic, he added. “All the materials we have [on the device] running in our office now come from Home Depot – we’re talking PVC, not stainless steel.”
Because the compounds deposit themselves on the electrodes, constantly repairing themselves as the device splits water, this technology can also use salty or dirty water, he added, a big advantage where clean water is in short supply. While normal electrolyzers shut down in minutes if they’re run on dirty water, Sun Catalytix’ electrolyzer has already run for days at a time with no degradation, Metcalfe said. In addition, if the hydrogen is converted back into electricity, the reaction produces clean water as a byproduct, a potential plus, say, off the grid in Sub-Saharan Africa.
Sun Catalytix hasn’t yet decided whether its ultimate product will be electricity or fuel, Metcalfe said, adding that the technology could potentially address any application that currently relies on a big diesel generator. For example, the technology could be used to provide backup power for telecommunications towers or mobile land bases for the military – and the hope is the technology could eventually target residential and commercial markets, as well, he said.
Make no mistake, the startup is still years away from commercialization and doesn’t yet have a market plan in place. It’s currently working to meet technology milestones under the two-year ARPA-E contract, Metcalfe said, adding that Polaris generally aims to invest for five to seven years. Sun Catalytix will have plenty to prove, including its efficiency, stability and reliability, as well as its ability to manufacture its devices cheaply and at scale and volume, before it can meet its potential.