Solar and wind power have variability in their productive hours, as multi-day weather events can impact output. Therefore, multi-day storage that is cost effective is important in grid reliability.
Boston startup Form Energy developed technology to address this need, revealing recently the chemistry behind their iron-air batteries. The company said its iron-air batteries can store renewables-sourced electricity for 100 hours at system costs competitive with conventional power plants. At full-scale production, Form Energy said the modules would deliver electricity at tenth the cost of lithium-ion batteries.
The iron-air battery is composed of cells filled with thousands of iron pellets that are exposed to air and create rust. The oxygen is then removed, reverting the rust to iron. Controlling this process allows the battery to be charged and discharged.
$200 million in Series D funding has been secured for the project, led by $25 million from ArcelorMittal’s XCarb innovation fund. ArcelorMittal will non-exclusively supply the iron materials for the battery system production, and Form Energy said it intends to source its iron domestically, manufacturing the batteries near where the iron was sourced.
The company’s first project is a 1 MW / 150 MWh pilot installation with Minnesota-based utility Great River Energy, located near the American Iron Range. Form Energy said it expects to have the facility deployed at a Great River Energy power plant by 2023.
Mateo Jaramillo, CEO and Co-founder of Form Energy, said, “We conducted a broad review of available technologies and have reinvented the iron-air battery to optimize it for multi-day energy storage for the electric grid. With this technology, we are tackling the biggest barrier to deep decarbonization: making renewable energy available when and where it’s needed, even during multiple days of extreme weather or grid outages.”
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This one’s got me wondering- their website says they can install 1-3MW of storage per acre. It could be I’m not seeing this right, but does that seem troublingly low? I usually don’t think much of the “renewables use too much land” argument (you can put solar on all kinds of dead space that’s already developed, wind on active ag land, go offshore, mining and drilling and ethanol use space too, etc.), but- does this use too much land? I suppose you could stick panels up on top of the warehouse enclosure for these if it’s sturdy enough?
I think they said 1 MW storage per acre, with 100 hours of output, which would be 100 Mega Watt Hours of storage per acre.
Perhaps they would work as well underground as over?
There’s always mining operations doing reclamation work, for instance, the mine the iron ore was extracted from. Then the surface could be used for whatever is appropriate.
Just for perspective Grand Coulee generates 6,800 MW/81,000 acres so no MW to acre storage seems pretty reasonable. Also I think it could be achieved mostly below ground at a greater cost of course. But the land could still have dual usage.
It also says it is 4 days/100 hours of storage. You have to multiply the MW by hours to get energy in mwhr.
It looks like it is 1-3MW of power for 100-150 hours at that level. So 100-450MWH of storage. That’s around 1500 to 6750 Chevy Bolt batteries worth of storage.
Hope this tech matures for full deployment. One tenth of the cost of litium is too feasible. If it occupies larger land surface area that might make in unsustainable for commercial feasibility it can be offsetted by installing a solar panel above the plant to offset.
In the above picture, the solar panels are spread out separate to the energy storage ‘containers’. I’m sure the PV panels could be mounted on top of the containers?
Also, is there any reason these containers couldn’t be stacked, to create a much less surface area spread for the ‘battery’?
Do they need a certain space between the containers to negate any magnetic attraction between the containers?
If these are big tanks of iron, they’ve got to be VERY heavy- pure iron (they won’t be pure iron, but stick with me) is 500lbs per cubic foot. There are probably some challenges and practical limits to stacking them- that 1-3MW/acre range they offer might be a clue to that.
Re: spacing the containers, the shelter itself makes me wonder if it’s important to keep these in a specific operating temp range, or if they can generate a lot of heat.
I welcome any new battery tech but they really need to start mentioning number of charge cycles and energy density. For many applications, low cost is not enough.
How is this technology different than ESS Inc.?
I wonder about the efficiency. Creating rust is how hand warmers work so the process is quite exothermic. Also if you’re only getting 1 MW of power per acre, that’s a lot of land use. I wonder how fast it can charge.
This technology is already developed and in production currently in a brewery in the Netherlands https://www.iom3.org/resource/iron-fuel-first-news.html