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Comment by walrus01 | Hacker News Reader

as a potential owner of a solar home with large (DIY) powerwall type storage: I am not a fan of this idea. I know how cycle life and cycle depth affects the overall lifespan of LiIon, LiPo and LiFePo4 type batteries. I want to control how many times my home cycles its batteries from full down to 10-15%, how deeply it can discharge, etc.

I do not want some remote agency controlling the discharge of my home battery, except in a miraculous future scenario where we invent batteries that are good for 20,000 deep cycles with <5% degradation over 20+ years.

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Nickle-Iron batteries have 50k+ deep cycle lifetime, though they are expensive and have numerous other drawbacks (poor efficiency, high self discharge). They are typically found in applications where cycle life matters more than any other parameter.

> except in a miraculous future scenario where we invent batteries that are good for 20,000 deep cycles with <5% degradation over 20+ years

That future may not be so miraculous since various flow and liquid salt batteries supposedly offer such properties. But you probably won't see them in homes since they only work economically at larger scales.

Would you accept the trade off for significant subsidies on installation?

also, but think the jury is still out on the power walls, there is evidence that Tesla batteries in Model S have much reduced battery degradation than previous experience would suggest. Which is interesting but needs more study

Build and deploy the homebrew system quickly if you want to avoid California Rule 21-style grid support mandates. Depending on where you live and how cooperative (!) your utility is it may already be too late. Good luck

Once off grid solar battery tech is mature it will transform the housing market. Hoping the utility bureaucrats and their captive politicians don't destroy this opportunity by commandeering our batteries

I have a hard time believing this. There's simply not enough lithium in the world to support every house having its own battery, let alone support all of the EVs coming into production.

Besides, there's genuine benefit being hooked up to the grid. I'll gladly pay the $10/month interconnection fee just to have that as a backup to my battery.

There is plenty of lithium. Reserves are low because until recently demand was low and so no one bothered to go and look for more. And then there is virtually unlimited lithium in the ocean, which costs more to get, but would still be a small part of battery costs.

The bigger problem is cobalt,but from what I understand people are working on various alternatives.

Or if they subsidize the purchase.

If this usage means having to replace the batteries more frequently (or at all; for some people they might last a lifetime with typical use) will they subsidize the cost of replacement too?

Otherwise it's a losing proposition for the homeowner.

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