[cbkeller]

Seasonal storage is an interesting idea. Rare grid outages seems pretty easy with batteries if the South Australia example is anything to go by though, and for medium-term storage there's also pumped hydro -- not sure where that compares in cost?

[pfdietz]

Rare prolonged outages are bad for batteries, since the capital cost is too high. You want something that has very low capital cost, even if it burns a fuel. Simple cycle gas turbines power plants might cost $0.50/W.

[Retric]

Existing battery technology works best when you don’t charge to 100% or discharge to 0%. On top of this you want oversized batteries to deal with battery degradation over time. This means any large scale battery system includes a buffer beyond normal use which you would only use if wholesale prices spiked.

On top of this grid operators want generation redundancy in case an individual power plant goes offline for whatever reason. Combining both you get quite a lot of excess capacity compared to the current grid.

[eru]

> Rare prolonged outages are bad for batteries, since the capital cost is too high.

You could subsidies that by using your batteries to energy to peak load times?

[pfdietz]

Batteries sufficient for short term leveling would run out too quickly. If you build enough batteries for prolonged outages most of them would be unused during the leveling of short term fluctuations.

[liketochill]

How long can south Australia power their load from batteries? I thought they had the one 100MWH battery so basically could power 100k house for an hour? And that battery was over 100 million dollars.

[defrost]

South Australia’s incredible week: 104.1 per cent wind and solar over seven days

https://reneweconomy.com.au/south-australias-incredible-week...

   South Australia aims to reach 100 per cent “net renewables” within a few years – over a full year – but in the past week it has already done better than that.

It would appear they are aiming to export excess renewable power to Victoria (neighbouring state).

[liketochill]

I thought we were taking about battery capacity preventing a blackout during a major grid outage and not installed renewable capacity meeting the demand.

[defrost]

.South Australia had (maybe still has) the "world's largest battery" (installed by Tesla | Musk) which is an integral part of the SA state power grid that carries it through night times with no wind . . .

If there's "a major grid outage" no large scale battery (or gas fired plant or coal fired plant, etc) will prevent blackout .. as there is "a major grid outage" preventing power from being delivered.

Individual homes would be left to do what individual Australian homes do during bush fires, floods, tree falls, etc and turn to gas lanterns, home generators, and any community hubs that feed local rooftop solar through a local small scale battery (not common as yet, but they're about and increasingly so).