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Comment by laurencerowe | Hacker News Reader

Longer duration battery storage is going to be very hard to make work financially since the capital costs are spread across far fewer charge/discharge cycles. At this point I feel it's more likely that it'll be cheaper to massively overbuild solar generation capacity to provide enough power in the winter than build seasonal battery storage.

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Why do you say that? Researcher Jeff Dahn, who is a co-inventor of the lithium ion battery, has released what he termed a "million mile" electric vehicle battery. That is a pretty high level of charge / discharge cycles and seems like it would make stationary storage batteries, such as Tesla Energy's 3MWh Megapack.

https://cleantechnica.com/2019/09/09/jeff-dahn-claims-new-po...

I read 'duration' as the charge/discharge cycle time rather than the battery's lifetime in number of cycles. Clearly the more cycles a battery can handle the more cost effective it will be (more cycles over which to amortize the capital cost) but you still have to pay interest so even if the battery can handle infinite cycles if you only cycle it once a year (to balance seasonal differences in generation capacity) it will probably not be cost effective.

I think stationary storage batteries are great, but only for short duration storage (1 day) rather than long duration storage (months).

Yes, that's precisely what I meant for the term; storage that is economical even with few discharges cycles per month or maybe even per year.

I am somewhat skeptical that it can work, but flow batteries are still in their industrial infancy, and with the right sort of cheap stuff to add to water this could potentially scale very well for some sources.

I also strongly agree that we will likely build renewable sources to match their output to the seasonal minimum needs, rather than have many TWh of storage, it I have been so wrong in the past that I no longer want to cut off potentially promising avenues.

I see our future as being one of electrical energy abundance at nearly all times, and only a few times a year will there be a crunch to limit consumption; however as we get used to that abundance, conservation could get more difficult, and also people will get far more clever with time arbitrage of energy demand. And once there's a huge market for arbitrage, people will get more clever to serve that economic need, in ways that we have not yet anticipated.

Gigawatt-hours are coming online in the next few months:

https://www.greentechmedia.com/articles/read/say-hello-to-th...

This project is a (very large) lithium-ion battery which will presumably be used daily. It's not designed to store power between seasons.

I don't think you want to use batteries to store power between seasons, since things like Hydrogen or Methane are cheaper.

> Longer duration battery storage is going to be very hard to make work financially since the capital costs are spread across far fewer charge/discharge cycles.

The same argument could be applied to solar panels (25 year warranty) or fibre optic cables. But as so many solar panels are required they will be producing them for decades before the market is saturated. Of course after decades the old ones have indeed started dying, so it isn't an issue.

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