I'll admit this sounded cool when I first heard about it; but it's actually a lot harder to program if you want to be able to recover from sudden power outages (which would be the main reason for having persistence in the first place).
No, it sounds good, because it's realistic and then you can build mitigation strategies.
I was recently involved in an outage that occurred because the sama datacenter was hit by lightning three times in a row. Everything was redundant up the wazoo and handled the first two hits just fine, but by the time the power went out for the third time within N minutes, there wasn't enough juice left in some of the batteries!
Now would it be possible to build an automated system that can withstand this? Probably. But would your time & money be better spend worrying about other failure modes? Almost certainly.
For a prolonged power outage, the hibernate feature is probably more useful. And a UPS to perform it. But generally not impossible to survive such an event.
You would basically need to isolate yourself from the grid to be immune to any blips...it takes a while for a backup to come on line and even things out.
Absolutely, and I think that is why a lot of people are reluctant to do it. It's a fragile process and if you lose power or have a random cosmic ray hit at the wrong time it's game over.
But there is a difference between "quite hard" and uneffected by sudden losses of power. It is easy to make it the later, and then suddenly the "extra safety" is simply unfounded paranoia.
The grid is not that simple, and many/most solar installs will not work in an outage to prevent islanding. It's extremely dangerous to have a section of wires live during an outage.
4-9's of uptime doesn't match my lived experience in the US, that's one days worth of power outage every 10000 days, or about once every ~30 years. 2-9's is closer to what civilians in the US are used.
The over provisioning could be considered more of a feature than a bug, offering new economic periods where the marginal energy cost of production go negative at times.
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