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Zinc-air batteries vs Tesla Lithium Ion for Grid Storage

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user212_nr

Active Member
Aug 26, 2019
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I just learned about the zinc-air battery storage technology that is being tested in NY (Zinc8) and also in use by a California company (NantEnergy).

It seems like a major breakthrough until you consider that its efficiency is only 65-70% (link) vs 99% for lithium ion. The linked reddit thread has a comment "I'm trying to think of a situation where the $45/kWh for additional power and lower efficiency makes sense for longterm storage".

I have the same question. Assuming that the battery is used rarely (ex. blackouts), then it definitely makes sense to sacrifice efficiency of energy for upfront cost of storage, but that is a very niche market. It is not the billion dollar market that these companies are trying to address. Plus, they are mechanical systems that need to be maintained.

article

Lets say you have a 100 kwh battery at $45 /kwh = $4,500. Lets say you use 100 kwh per day (one cycle day + night), then you have 36,500 kwh per year. You loose 30$, or 10,950 kwh, $2,190 per year.

Compare that with $20,000 at $200 /kwh. The lithium ion battery pays for itself (breaks even) in 7 years. That is a long time, I think. Maybe there is something there, especially if lithium supplies are limited. Or maybe both current lithium and zinc-air are too expensive?