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Comment by cassianoleal | Hacker News Reader

Utility-scale solar might be cheaper but doesn't make my house resilient to grid failures. It also only benefits me when the grid is upgraded enough that ... well, it benefits me.

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Plug in solar doesn't make your house resilient to grid failures either. You would need an inverter that can generate an AC output without having an existing one to follow; a disconnect to isolate you from the grid during an outage, batteries to smooth the output, an electrician to install it, and an inspection to certify that it was all done correctly.

If you are going through all of that, there is not much benefit to plug-in solar instead of traditional.

Most of the balcony solar packages already include what you need. They include a battery and on that battery is a receptacle that will supply power if there is no mains. The dogtail that you insert into your house outlet only supplies power if there is mains, but the receptacle on the battery supplies power regardless.

So when the power goes out you unplug your fridge from the wall and plug it into the battery. In essence it operates like the standard camping battery/"solar generator", a la Jackery et al.

To gp’s point, if you’re going through it all just implement it at your panel/subpanel. Mine does auto switch over to power the entire panel and I only know about it from an app notification. Then I can decide if and where I want to power down usage in the house to conserve battery.

Having to plug in individual appliances seems to defeat the entire purpose. What happens if you’re away on holiday? Come home to a fridge full of trash? If power is back, do you even know how long the outage lasted? What about other devices that generally should have nonstop power or are typically hardwired? Sump pumps, HVAC equipment, water heaters, etc.

Spending $3000 to add auto-switch to a $500 battery is not something most people are going to do.

What’s the cost of these half baked solutions? My cursory search shows about half of that or more.

You can go as far down the rabbit hole as you want. Most people don't have anything critical that needs to have power 100% of the time, a few hours without power won't hurt your fridge. The odds that the power goes out for long while you are on vacation is low enough that you can ignore it - besides most people tend to have less in their fridge when they go on vacation.

Where on the risk spectrum do you fall? I have a battery backup sump pump because I learned the hard way what happens when the power goes out and the generator doesn't start. If I fixed my generator though I'd have an automatic system that would run my sump pump, furnace, fridge, well, water heater, lights, computers, range, - and lots of other useful things as well so long as I'm careful about I run at the same time (anyone know how to fix a 1970s generator?)

I live in an area that has outages a few times a year. It's usually weather induced so rather unable to plan. But, I know we usually have 2-4 days without power and I just want to be comfortable in my home. Sometimes 1 day at a time, sometimes a full week. We also have regular short outages (eg rolling "brown outs" in heat of summer), more of an annoyance than a risk but if the investment can also smooth these out then it's just extra reason to do it. The biggest actual fear is the winter version means broken pipes since I'm in a warmer climate and houses aren't built to survive freezing temps without heat. But, I want to also be comfortable in my home while hunkering down (need the HVAC equipment to run), I want my food to stay good (fridge), I want warm water (water heater), and since it's an extended duration I want entertainment (internet/TV to work). I can do without a lot and do power off many things when I'm running off battery (eg. no laundry, dishwasher, etc). Since these are all over my house, different circuits, and some are hardwired appliances with no "plug in" ability - the solution is at the panel. My arguement is that most people should invest at the panel too, because they can't expect what would change. But, I suppose most people buying these value portability as balcony may hint towards rent vs own. That's a whole other topic, if you don't own the property then anything portable is probably best even if the solution is inferior.

These panels do not work without the grid.

(And this is intentional to avoid electrocuting line workers who are working to fix the grid when it breaks)

Line workers ground everything before they touch any conductors, except in some cases where they intentionally work "live."

This is the truth. Aside from solar there are plenty of folks with backup generators that automatically come on whenever grid power fails. When maintenance crews came through my neighborhood to upgrade the old pole fixtures, they grounded out each block to keep any backfeed off what they were working on.

Yes. A properly installed generator or solar/battery setup should not backfeed when the grid is offline, but the line crews don't depend on it.

No, it's more than that, it's not just a safety feature that you could disable: the plug-in panels need an existing waveform to synchronize to, if the grid is dead they can't produce an AC voltage signal on their own.

We know how to make inverters that can produce an AC voltage on their own. It is not particularly difficult or expensive. The reason why we do not put those inverters in plug-in solar units is entirely because we don't want them to have that ability.

Nobody claimed we didn't know how. You're misunderstanding the point of these panels.

Those are a different design inverter than cannot plug into a wall. It isn't hard to design either type, but they need different designs in some critical areas. (you can design one that will do both as well, but it would be more complex)

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