New Battery Tech Energizes Demand

CEO Craig Evans at the Wilsonville facility. Sander Gusinow CEO Craig Evans at the Wilsonville facility.

The iron-flow battery system is safer, cleaner and more durable than its competitors, but its success will depend on its ability to scale.


In 2011 Craig Evans started Energy Storage Systems from a lab he set up in his Portland garage. His goal, along with co-founder and chief technology officer Dr. Julia Song, was to create an industrial-grade battery that could solve one of the biggest problems preventing more widespread use of renewable energy: how to harness solar and wind energy when the sun isn’t shining or when there is no breeze.

Eight years later, Evans’s production facility in Wilsonville has the same plucky design, though it’s a good deal bigger. It looks more like a science fair than a factory, with reams of exposed wire, glass cauldrons of rose-tinted water, and a gigantic iron tank that looks ready to dive 10,000 leagues under the sea.

Evans’s new battery system, called “iron-flow,” stores energy using iron and other non-toxic materials. Although the bubbling liquid looks like a chemical bath, according to Evans, it’s actually safe to drink (though he doesn’t recommend it.)



“Instead of using organic electrolytes, we use iron and salt water,” says Evans. The CEO claims his patented power storage system isn’t just an eco-friendly alternative to the lithium-ion battery; it’s an upgrade and a more sound investment.

As renewable energy becomes more prevalent, larger batteries, like the ones manufactured by Energy Storage Systems, become more vital to store renewable energy on a larger scale. Batteries have big advantages over other forms of distributing renewable energy since they do not require infrastructure, or be connected to a power grid.

Granted, lithium-ion batteries can store wind and solar energy too, and for the moment, they can do so more cheaply. But lithium-ion batteries are not without cost. The process of creating conventional batteries consumes a staggering amount of water, and has the potential to leak toxic chemicals into the water supply.



Lithium-ion batteries also pose fire and combustion hazards as they degrade over time, and can only be recycled at specialized treatment facilities able to handle the chemicals.

The new iron-flow batteries pose no such risks. The food-grade ingredients that go into the batteries have no threat of fire hazard, nor risk of combustion while operating in hot environments, such as deserts and equatorial regions.

As global temperatures continue to rise, such considerations could become more important.



The components of the new battery system can cycle indefinitely. Unlike the lithium-ion battery you might find in your cell phone or electric car, which loses a bit of its capacity after each recharge, the iron-flow batteries don’t lose their maximum charge.

This durability means iron-flow battery systems are 25-year assets instead of just 5 to 7-year assets like lithium-ion batteries.

According to Evans, scale and price are the keys to making any battery commercially viable. It’s also the biggest challenge facing his startup.

“If you’re going to be competitive as an energy company you’re going to have to offer low cost at low volume. Lithium-ion batteries are low cost due to their large scale, which makes it harder for new players to get into the market,” says Evans.



Although the technology is still in its infancy, investors are already taking note of the energy storage device.

Last month Energy Storage Systems received a $30 million investment from a funding group, which includes Evergy Ventures and PTT Global Chemicals. The new funding will be used to expand and automate the manufacturing process, bringing costs down and production up to scale.

The new batteries may not have taken over the market just yet, but demand is on the rise. At the time of this article’s writing there are 2 iron-flow systems in use and 8 additional units on order.

Time will tell if the iron-flow battery will grow to the scale where it can replace the lithium-ion. The new units might be the safest and the cheapest, but according to Evans, that’s not most crucial piece of the puzzle.

“In terms of what’s important to consumers, it goes price, safety and sustainability in third.”


To subscribe to Oregon Business, click here.

Leave a comment

Make sure you enter all the required information, indicated by an asterisk (*). HTML code is not allowed.