[alexey-salmin]

Exactly, like growing potatoes made economic sense to my parents' generation.

Economic sense is largely defined by the economic policy set by the government. No one puts balcony solar in France, somehow their economic sense is different.

[piva00]

France has changed permitting laws to allow small-scale solar, i.e.: balcony solar, the difference is that the nominal output is much lower (350W vs 800W for Germany) which, by policy, makes it less attractive.

So it isn't that France economic policies have made installing balcony solar unattractive, it's the permitting policies which are blocking people from installing more.

You have it inverted, pun intended.

[kragen]

Germany could allow 2000W, or 4000W, instead of only 800W, but you seem to be missing Alexey's point.

Germany has very high electricity prices, even higher than the US (see https://worldpopulationreview.com/country-rankings/cost-of-e...), and this is due to policy failures in Germany. That's what makes these balcony systems so appealing.

I'm not sure that the outcome of having a lot of decentralized solar generation is a bad outcome.

[adrianN]

The 800W are to prevent fires. You can’t just arbitrarily raise those limits.

[kragen]

What do you mean about preventing fires? 800 watts at 240 volts is only 3.3 amps. Are you saying there are German houses where you could plug a solar power system into an outlet whose wires would pose a fire risk if they carried 4 amps? Because I think the minimal rating for a German residential outlet is 16 amps, which would be 3520 watts at 220 volts.

While I agree that you can't just arbitrarily raise safety-based limits, not all "safety-based limits" are actually safety-based, and I'm pretty sure you've misidentified the safety concerns in this one.

[adrianN]

That's 3.3 amps behind the breaker. So if your wiring is set up for 16 amps you can now draw 19.3 amps before the breaker kicks in. That's within the safety margin. But if you allow PV to feed in more you exceed the safety margins and can cause the wiring to overheat.

[kragen]

Hmm, I guess you're right. If your oven is plugged into a different breaker than the one where you plug in the solar panels, that doesn't happen, but most people won't know which outlet is on which circuit. Thank you for explaining!

[baq]

caveat - 20 amps on a b16 breaker will take a very long time (minutes to hours) to trip; in practice, you may never see it tripping during normal usage, but yeah your walls will get a bit warmer.

[piva00]

No, I didn't miss the point, I know they were talking about electricity prices. My counterpoint is that France is not seeing balcony solar not only because electricity prices are lower but due to policies which limit it.

It's a both-things can be true, even though France has also been getting more issues with electricity generation from its nuclear fleet caused by droughts, and high temperatures in their cooling water supply.