Comment by KirinDave | Hacker News Reader

Comment by KirinDave | Hacker News Reader

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> and most of the energy will need to be thrown away.

I won't speak to the veracity of your numbers. I have no idea your methodology or even if you're qualified to do an analysis here or the quality of your data, so...

But I will point out that the current plan to address this is to repurpose and recycle existing lithium ion battery packs at sclae, while continuing to develop very large electrical energy storage methods.

A real-life example of this is Tesla's Australian contract (https://www.reuters.com/article/us-australia-power-tesla/tes...) which uh... literally started on twitter as a dare between rich people (https://twitter.com/elonmusk/status/840032197637685249?lang=...).

Very large power storage stations like this actually offer a lot of utility in a variety of scenarios. Not only do they make distributed grids much more reliable offer a facility to ground out excess energy on the grid (helping reduce the impact of solar phenomenon over large-scale transport networks), but they also have a lot of value in disaster recovery scenarios.

Sure, my calculations assumed about 48 hours of storage. But there's a pretty big difference between 48 hours and seasonal storage where you need weeks (400 hours).

What Tesla is currently doing is installing about 4 hours of battery for the typical site, so about two orders of magnitude away from being able to scavenge all that wasted power on a fully PV grid, but fairly optimal to ensure full use of stored power.

It is key to understand the seasonal variation of sunlight. This is a much worse problem at high latitudes. But at lower latitudes (say, anything less than 45-50 degrees, i.e. >80% of the world's population), PV is now cheap enough it's cheaper to just over-size the PV array to provide power even when it's cloudy and/or winter than to provide weeks or months of storage.

EDIT: Maybe "wasted" is the wrong word. Is your car engine "wasted" just because it's not red-lining 24/7? Averaged over a year, your engine only has a "capacity factor" of about 0.2%, but the energy is there when you need it, and it's still affordable. Likewise with solar, it's okay if not all the electricity is utilized, as long as it produces enough on cloudier days to not require a ton of storage (up to ~50 hours of storage is fine).

Forgive me, but it seems to me like you didn't read the materials that I passed you in instead based your commentary on Tesla's powerwall product?

> "...but they also have a lot of value in disaster recovery scenarios."

How so?

I'd imagine that you'd need a pretty large capacity battery storage system in order for it to reliably act as a blackstart generation source.

EDIT: I did some quick research, found this recent article about IID's blackstart battery testing - https://www.energy-storage.news/news/california-batterys-bla...

Thank you for linking this, I neglected to do so in my original post.

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