Germany outfitted half a million balconies with solar panels

I don't think so. This is well studied. The LCOE of rooftop solar is terrible compared to utility. I can't imagine what it looks like for balcony.

https://www.investigativeeconomics.org/p/solar-is-only-cheap...

Maybe a most important benefit is it makes people MORE aware of their actual daily electricity consumption ...?

I think you're misunderstanding plantain's point.

Where I live, in Argentina, every house has a water tank on the roof, which is filled from the water main through a float valve, like a toilet tank. Many houses need a pump to drive the water up to the water tank because the water main has such low pressure. This is somewhat expensive, and the pumps, float valves, and water tanks fail sometimes, which is inconvenient. And the tank is not really that high up, so the water pressure at the faucet is not that high, and it's somewhat variable, which is inconvenient when it changes the temperature of the shower.

Some other places I've lived, such as various places in the US, instead have a large shared water tank for an entire neighborhood, town, or even city—a so-called "water tower". If you've been to the US, you may have seen these. Making this work involves several expenses:

- Larger-diameter water mains to reduce head loss when water demand is high.

- Highly responsive repair crews to respond rapidly to water main breaks, because the higher-pressure water with a high flow capacity can be very destructive.

- The construction and maintenance of the large water tower, which is very dangerous if done badly.

- A high-powered pump to get water up the water tower in the first place.

However, these expenses turn out to be significantly smaller per person than the expenses of small per-house water tanks and water pumps. And they provide better service. (Also, because people are stupid, in the US they build many of their houses out of wood, so they need fire hydrants, which require the larger water mains anyway.)

So, the fact that people in my neighborhood Argentina are spending more to get worse water service is a failure of coordination.

Of course, people in the US can still put water tanks in their houses if they want to. In earthquake areas, it's even recommended to have a store of potable water that isn't dependent on the water main. But, because they have succeeded in collectively building excellent municipal water systems, they generally don't need to.

The claim that plantain is making is that people actually choosing balcony solar panels is a symptom of a similar failure of coordination. To me that seems plausible but not necessarily correct, for reasons I've explained in https://news.ycombinator.com/item?id=45487051.

Are deaths per megawatt really better if one looks at total infrastructure deaths from transmission wires and the like?

That page, although it was written only four months ago, is citing LCOE figures from 02021, when mainstream solar panels cost €0.25 per peak watt. Now they cost €0.100 per peak watt—see https://www.solarserver.de/photovoltaik-preis-pv-modul-preis.... Power electronics and batteries are also enormously cheaper now. Also, note that the LCOE numbers it cites are for the US, where most of the costs stem from the US government's anti-renewable-energy policies such as punitive tariffs, policies that are not in effect in Germany.

That page also undermines its credibility by citing the hypothesis that the low cost at the time (which it acknowledges was already down to 36% of the number in 02012) was because the "massive wave of imports" was "subsidized by China’s central bank"; if that were the case, you'd expect that once China owned the world's solar market, the prices would have gone back up to reflect the true costs of manufacturing the panels, so that China's central bank could stop hemorrhaging money in these subsidies. Instead, the prices have continued to drop. They've dropped as much in the four years since that report as they had in the nine years before it. And, if you read the Department of Commerce filings justifying the "anti-dumping" tariffs, you will find that the arguments being made about "subsidies" are transparently ridiculous; the supposed "subsidies" include the fact that Chinese panel manufacturers pay their workers less than Turkish electronic assembly workers, and the fact that they have good public infrastructure to use.

It also incorrectly claims that solar panels need to be replaced after 25–30 years (that's just the warranty period) and that doing so would add US$20–30/MWh to Lazard's US$36/MWh LCOE, which is an obviously an arithmetic error that's off by orders of magnitude.

But its central claim, that rooftop solar is much more expensive than utility-scale solar, is actually true. The reason for this is mostly that rooftop solar requires much more labor and enjoys poorer economies of scale. You have to pay someone to design custom racking for your particular roof and a custom inverter and battery storage system for your house, pay someone to climb up on your roof and possibly die, pay for permitting and inspection, etc. You can find a more detailed breakdown of "turnkey installed cost" in SEIA's Solar Market Insight Report https://www.seia.org/research-resources/solar-market-insight....

However, all of these factors are completely the other way around for balcony power plants. You don't climb on the roof; you walk out onto the balcony. You don't design custom racking; you buy an off-the-shelf retail product. The same thing for battery storage, if you buy a system with battery backup. Instead of spending thousands of dollars, you just hang the solar panel off your balcony like a potted plant and plug the plug into the outlet. The engineering is being done at the factory for a mass-market product, not for your house or for a single utility-scale solar farm. So you're spending less in engineering and permitting and construction costs than a utility-scale solar farm would, not more.

There is one way in which balcony power plants are worse than rooftop solar: they are at terrible angles, so they don't get much sun. But that just means you get less power, maybe two or three times less than you'd get in an optimally-designed utility-scale plant. That matters much less now that solar modules are so cheap.