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Comment by dotancohen | Hacker News Reader

Unlike Lebanon, though, one cannot legally operate their solar panels to power a home while the electric grid is down in Israel.

From what I understand, the Lebanese are used to working around the failings of their government in all aspects of life: work, shopping, now banking, and even education where possible. I don't know about water supplies or roads, but from what I heard the Lebanese view their government more as a siphon of their earnings and resources than as a provider of services and order.

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> Unlike Lebanon, though, one cannot legally operate their solar panels to power a home while the electric grid is down in Israel.

That’s fascinating! Can you say more?

Not the parent.

It's likely a safety issue in the case of grid-connected solar installations. These panels are designed to send excess electricity to the grid, and if the grid is down, the utility needs to make sure that busted cables are not carrying electricity... for the safety of the repairmen.

https://www.cnet.com/home/energy-and-utilities/do-blackouts-...

Preventing backfeeding during an outage isn't a hard problem, technically speaking...

It's a default feature in grid tied inverters from what I've been told.

Yes, but the most common way they do this is just by shutting down completely and not accepting any input from the solar panels.

You need to move up to more expensive models that support “islanding” to be able to use solar power while the grid is down. For some reason it appears that this type of inverter isn’t legal in Israel?

In Sweden the same applies, at least if you have panels that can feed back excess into the grid for payment.

In case the main grid goes off, your equipment is supposed to stop working so that it doesn't feed power backwards into the grid while some person is trying to fix whatever broke, so unless you have a battery/UPS and a large switch to flip, your solar panels "die" along with the grid.

The alternative would be to have totally separated panels, but many opt in to selling excess back, since it gets more and more profitable as prices go up.

>The alternative would be to have totally separated panels, but many opt in to selling excess back, since it gets more and more profitable as prices go up.

Totally separated solar panels would also mean you barely have any electricity on that circuit for half of the year.

Another option is an inverter that can sense the net and switch that flip automatically, but they are more expensive and still not legal everywhere because it's not really needed in Western European countries.

Adding a battery and switch is the obvious solution to the problem. I'm in the UK and ended up going for the Powerwall 2 and Tesla Gateway, alongside our panels.

The installation had to be certified by the electricity company to ensure that it operates safely in the event of a grid power outage, but (in theory as we've not had a power cut since installation) it should all work fine.

Nevertheless you should regularly test it, at least once a year.

Many a datacenter outage could have been prevented had there been more regular testing of all the components involved.

> The alternative would be to have totally separated panels, but many opt in to selling excess back, since it gets more and more profitable as prices go up.

AFAIK the latter part is now less and less true in Germany because the price for selling excess back is only a fraction of the cost of getting power out of the grid, so people are installing batteries, heat storage and controllers that switch heavy consumers like their heat pump according to other loads in their house.

I have a phocos anygrid 5kwh solar inverter. It is a regular grid tie inverter but once grid goes down, it continues in off grid mode even without batteries so this inverter would be perfect without breaking any laws

I have this kind of system too, but when I wanted to get solar for the other side of our roof after our neighbors took down a tree I learned that they're no longer allowed in MA for new installs. Starting with the 2014 National Electrical Code (NEC) you need to have some form of rapid shutdown to protect firefighters in an emergency, and in the 2017 revision it got much stricter to where the SPS functionality would have to be completely redesigned to qualify. The only option now, as far as I can tell, is the recently released Enphase IQ8 Sunlight Backup. It's very expensive: I got some quotes and it added about $7k (23%).

I think you can by simply disconnecting from the grid. This is a obvious prohibition, same reason why male-to-male electrical cables are prohibited and not sold: doing so will electrocute anyone trying to fix the grid.

The solar power inverter needs the grid sine wave to sync to. Without seeing that sine wave, it will not produce power.

The naive solution would be to have a small 12v automotive battery and 240v inverter to generate the sine wave, and to use it only after fully disconnecting from the grid. However the sine wave that 240v inverters create are "digital" sine waves - they are easily discerned from the real analogue sine waves that a power station produces with spinning armatures and flywheels.

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