Cheap non lithium electrical storage

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

peakbagger

Minister of Fire
Jul 11, 2008
8,676
Northern NH
This flow battery tech just popped up on my radar. No strategic materials, looks like its commercially available. Definitely not for transportation (low energy density) but a nice duck curve solution which can be mass produced and quick. I would see it as nice match with a small neighborhood microgrid.

 
Yes, ESS has been making news lately.
 
The biggest issue is power density. Its takes up a lot of space and usually space is money but for the right site maybe not an issue. There was similar tech with better density http://www.viznenergy.com/news/ but they ran out of funding and I think is defunct.
 
Sounds like a local outfit here in PA bought a system. The local paper has some pictures and numbers:


A 400 kWh capacity 'Energy Warehouse' system costs 'about $200,000', or about $500/kWh. This is reasonable for a new tech system (not cell) cost, given its projected long service and cycle life.

For comparison, a much smaller 13.5 kWh Tesla Power wall is $11k MSRP and about $8.5k after rebates. This is about 50% higher per kWh than the ESS system. The price per kWh drops somewhat for higher capacity systems. Both Tesla and ESS appear to have a 10 year warranty (suggesting similar 20k cycle lives)

The EW system lives in 40' shipping container, with a dry (no electrolyte) mass of 20 tons. The electrolyte weighs another 19 tons. So that works out to about 10 kWh per ton, or 100 kg per kWh. This is more than 2X the weight of a lead-acid system (that has much poorer cycle and service life).

The question here is ESS's margins. It seems likely that their price point for the above system is set to compete with lithium systems and get units out the door and into the field. I would bet that at low production volume, they will struggle to make a profit. The production scale where they do make a profit is unknowable. The new 10% rebate from the IRA could be helpful. The price surge in lithium battery minerals will probably help them MORE.

What I liked from their website is that their 'second generation' cells delete all the O-ring seals and half of the plumbing fittings of the Gen 1. Yeah, 40 tons of cells held together with O-rings and (presumed off the shelf) plumbing fittings sounds like a prototype. They also have a robotized cell manufacturing system. This will be important for price reduction at scale.

Good luck to them!
 
My limited experience with these new tech companies is they do whatever they have to get some orders and equipment in place that are "good enough". These days there are plenty of SPACS out there desperate for a good prospect and if ESS has a few units in the field they will not want for investors. Once the SPAC happens, all the investors get a pile of money and some of it hopefully goes into the actual company to make viable company (some dont like Nikola, Lordstown and Canoo). Even if they have to replace the first deployments with new units, it still got them to the point where there is a gen 2.
 
A couple of alternative storage systems are under development. The first is the largest compressed air power system. This system is by Hydrostor is going in the San Joaquin valley. It will use solar energy to store compressed air in large, manmade caverns. The system is set to come online in 2028.

Another interesting approach is by Noon Energy. They are developing a carbon-oxygen battery based on work done by a NASA Mars Rover project scientist. The battery uses electricity to split carbon dioxide into solid carbon and oxygen gas. To discharge, it reverses the operation, oxidizing the solid carbon.
 
I've seen some of the experiments with storage reservoirs, pumping water in and out to store and retrieve energy. But water has relatively low density, and the height to which it is being lifted is not that great... seems we could do better with less space using a metal cube on vertical rails.

Just spitballing out loud here, but even a fairly inexpensive lead cube lifted to 15 meters would store 1.7 MJ. Make a simple 3x3 array of them, and you have 15 MJ (4.2 kWh) stored on a 9 m2 footprint. Double the height or material density, and the storage scales linearly.

These are pathetically small numbers, when compared to chemical storage, but still... way better than a reservoir filled with water. Metals have density 10x to 20x higher than water, and there's less issues with arranging it vertically to favor small footprints in dense environments. I guess the big advantage of the reservoir is that they're already existing, but to where do you move this water when pulling energy from the reservoir?
 
  • Like
Reactions: Ashful
Stored hydro takes up lot of acreage and the variable water level required means wildlife is impacted significantly. There was a project in Maine called Dickey Lincoln that pretty well shut the door on new stored hydro in New England. It was intended to store power overnight from nuclear power plants and then would discharge the power during the day. There was a pumped storage hydro built in Western Mass on the CT river intended to the do the same thing. The VT Yankee has been shut for several years but the pumped storage system is still running

Stacking concrete blocks is a pretty good storage method https://qz.com/1355672/stacking-concrete-blocks-is-a-surprisingly-efficient-way-to-store-energy
 
The concrete blocks seem like a very intermittent cycling reserve as the crane returns to get the next block. Perhaps that could be solved with multiple cranes working multiple stacks simultaneously. Seems like it might not work well in earthquake-prone regions.
 
I think the concept is multiple cranes on the same tower moving multiple blocks. I agree seismic design is a challenge.
 
Keying square blocks to fit together (like legos) might help mitigate some seismic concerns, but that is a tall tower of blocks. I wonder what the duration of sustained output is planned.
 
I've seen some of the experiments with storage reservoirs, pumping water in and out to store and retrieve energy. But water has relatively low density, and the height to which it is being lifted is not that great... seems we could do better with less space using a metal cube on vertical rails.

Just spitballing out loud here, but even a fairly inexpensive lead cube lifted to 15 meters would store 1.7 MJ. Make a simple 3x3 array of them, and you have 15 MJ (4.2 kWh) stored on a 9 m2 footprint. Double the height or material density, and the storage scales linearly.

These are pathetically small numbers, when compared to chemical storage, but still... way better than a reservoir filled with water. Metals have density 10x to 20x higher than water, and there's less issues with arranging it vertically to favor small footprints in dense environments. I guess the big advantage of the reservoir is that they're already existing, but to where do you move this water when pulling energy from the reservoir?
There is an example of stored hydro reservoir at the Holtwood dam on the Susquehanna river in PA that's been using hydro power to lift water for generation to meet peak demand times. Not exactly experimental, it's been in operation for decades (since 1968). Just pumps up to the reservoir at night, and down through the day. I remember seeing it 30 some years ago, it was fenced off and covered with waterfowl.


Also, I don't know how big the cooling towers are on nuclear plants like Limerick and Three Mile Island (yikes!), but capturing some juice by draining through a turbine seems like a good idea.
 
Last edited:
  • Like
Reactions: Ashful