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Comment by plantain | Hacker News Reader

You grow herbs at home because it's kitsch, fun, or even convenient, not to save money. Store harvested herbs die in the fridge, electricity does not.

In Australia, our government massively subsidizes putting solar panels on our roof, and batteries in our garages, for a $/kWh price wildly higher than could be achieved with economies of scale in an industrial installation.

Batteries are even more egregious than solar, why install batteries .one. .at. .a. .time. behind switchboxes where they can only be used individually rather than a suburban installation that allows them to be used in aggregate?

I can only imagine how badly the numbers stack up somewhere suboptimal for solar like a German balcony. What if everyone instead gave their 1000 euros to a state organization that built a big solar farm that everyone shared? Oh wait - that's exactly how the state is meant to work!

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The subsidy question is interesting, but in Germany these balcony panels are ~ €600 unsubsidized (depending on the exact kit; see my numbers elsewhere in this discussion) and still pay back in 5 years. The economics work with and/or without government help.

The fact the economics of DIY make sense, is the evidence of the market/state failure. (whether they really do make sense without fanciful efficiency calculations, I leave to you).

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

I think you need to make some better arguments to convince. Your argument only makes sense when wholesale cost of solar panels is significantly cheaper than retail. The better the economics of scale (i.e the smaller the difference between wholesale and retail) the more favourable "DYI" becomes, because the person had home does not need to cover the overheads that are necessary for large scale installations (financing, management, transmission, planning...). It's the same reason that hiring a vps to run all your compute is not necessarily cheaper than buying your own pc.

It makes sense for two reasons: firstly there's limited economies of scale in solar panels: they more or less make the same amount of energy per unit area and per dollar regardless of the size of the installation (rooftop is usually more expensive for installation but these systems have near zero installation cost). Secondly, because the generation is local you're not paying for any margin, co-ordination costs, or transmission costs. This secondary effect is already enough to offset the increased cost of rooftop installation in many cases.

(And maybe you can consider this a market failure, in that it doesn't fit some naïve idea of an efficient market, but you're always going to be paying for someone to make and take on the risk of the big, centralised version of things)

Installing balcony PV is kitsch, fun, or even convenient as well.

What does your vision of perfect solar power look like?

And within that vision, is a free person still able to decide for themselves if they want to buy a solar panel to hang on their balcony?

People are entitled to do as they want, even if it's not profitable. I am just pointing out that if the economics of this add up, people have been seriously let down by their governments.

According to the article, the economics of balcony solar pay off in less than ~5 years. That's really pretty good compared to approximately any other point in the history of solar power. The payoff is small, but the investment is also small.

Now, sure: That quick payoff is only possible because electricity in Germany is very expensive, but there's reasons for that, too: Unlike some nations, Germany isn't sitting on a ton of high-quality fossil fuels.

They do have lots of lignite, and they do mine it and use it, but lignite is so low-energy that transportation becomes a serious financial burden: A train full of lignite can cost more to move around than it can produce, Joule per Joule. They've solved some of that problem by putting power plants right next to the mines (which is smart: build transmission lines instead of rail lines!), but their domestic fossil fuel resources are not a matter of policy. They're limited to whatever they have in the ground.

And for reasons that must make sense to someone, they've completely phased out their domestic nuclear power. (I'm not interested in discussing whether that's good or bad, but it remains fact.)

As far as I can tell, electrical production and distribution in Germany is comprised of a mixture of private entities (eg, companies with profit motive) and public (government-operated) entities -- similar to how it is where I am here in the States, and also where you are in Australia.

And quite clearly: The private entities are obviously interested in maximizing their potential profit. They are, after all, principally in the business of making money.

It's easy to say that it's a governmental failure that ultimately allows balcony solar to have such a quick return... but private enterprise is also involved, so they get to share the blame as well.

If it is profitable to do solar power at utility scale, in Germany, then: Why isn't more of it being done? If the answer is "just rent a few thousand hectares at a few hundred euros per year and cover it all with solar," then why does the private sector not cash in on all the easy money of utility-scale solar power?

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.

You understood my point better than myself.

Thanks! I've been experiencing collective action failures acutely in recent years, so I'm glad my perspective was valuable.

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