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points by pyrale 3 days ago | 0 comments

> I have no idea how serious these reasons actually are.

Basically, the grid was built with the assumption that plants produce power, and that households only consume it. That means opening a breaker between the transport grid and the distribution lines should allow to safely work on the consumer-bound side.

That assumption no longer works if consumers energize the network, and while I assume workers have safety guidelines to check the line before starting work, there is still a risk.

Fixing this issue would require new remotely-operated breakers to be installed, which is costly, and it's hard to justify installing them proactively just in case.

[–] bluGill 2 days ago

Linemen have long be trained that a wire is either live or they have personally shorted it to ground. Even before solar, there are a lot of people with generators who didn't disconnect correctly.

[–] pixl97 2 days ago

When things like power lines fall down the system will detect and disconnect that portion of the grid, one problem with things like personal solar generation is you can keep feeding power to the fault and melt things down.

[–] bluGill 2 days ago

While possible, the reality is in almost all cases your home system will shut itself down from overload first.

[–] grumbelbart2 2 days ago

> Fixing this issue would require new remotely-operated breakers to be installed, which is costly, and it's hard to justify installing them proactively just in case.

No, the fix for this issue is that the inverter of your local solar installation checks if the grid delivers a 50 or 60 Hz waveform, and breaks if it does not. This is pretty much the standard in any installation today, and it's mandatory whether you declare your installation or not.

Side note, there is recently a push to vary the allowed deviation from 50/60 Hz a bit for each installation. The risk is that if all installations stop delivering at, say 50.1 Hz, then if the grid exceeds that value for some reason, there would be a very sudden drop in supply since all solar installations shut off at the same time.

[–] pyrale 2 days ago

> No, the fix for this issue is that the inverter of your local solar installation checks if the grid delivers a 50 or 60 Hz waveform, and breaks if it does not.

It's hard to apply regulation to people who already decided to skip declaring their setup. If everything was done by the book, the stuff would be declared.

[–] rsynnott 2 days ago

Generally the fix is to either have the inverter shut down if the grid fails, or automatically isolate the premises if the grid fails.

[–] cestith 2 days ago

Isolation via a transfer switch or breaker lockouts is the right solution. If the grid fails and your power inverter shuts down, your house is without AC power.