Germany outfitted half a million balconies with solar panels • Hacker News Board

Re: Germany outfitted half a million balconies with solar panels

#591

Post by Archelaos » Mon, Oct 06, 2025, 8:46 PM UTC

StopDisinfo910 wrote: post #482

Archelaos wrote: post #402

Earlier quoted context omitted.

Nuclear technology is a dead end. Renewables and saving energy is the future. Nuclear and fossil are in the same boat. They are both more risky and have huge hidden costs that the general public and future generations will have to bear. The only good reason to go nuclear these days is if you want the bomb, like Iran. Interestingly, it is the same people who supported fossil in the past who are still promoting nuclear…

Nuclear and intermitent energy sources have no place in the same sentence. Germany didn't avoid nuclear by switching to renewables. It does so by burning coal and building gas-fired power plants. How to manage a grid fully on intermitent power sources is an open question. There is at this point in time no answer to this. At the moment, Germany fires up extremely dirty power generation capacity every time there is a s…

This is all propaganda of the nuclear lobby.

> Germany didn't avoid nuclear by switching to renewables. It does so by burning coal and building gas-fired power plants.

Germany is constantly reducing gas consumption.[1] From 2000-2024 it reduced electricity generation from coal by 61%.[2]

> How to manage a grid fully on intermitent power sources is an open question. There is at this point in time no answer to this.

Only details are open. (Compared to the open question of long term storage of nuclear wast these are very minor problems.) The general strategy is clear: use constantly available renewables (offshore wind, geothermal), connect distant regions for mutual compensation, energy storage.

Personally I think it neglegible if a very small percentage of fossil technology were held in reserve for emergency power generators.

> At the moment, Germany fires up extremely dirty power generation capacity every time there is a shortage.

We are in a transition period. It is impossible to suddenly move to complete renewables. Responsible for the rather slow progress are not those people who pushed for the switch to renewables a long time ago, but those who wanted to drag it out as long as possible. These advocates of fossil fuels were the same individuals and companies that wished to extend the use of nuclear energy.

> Meanwhile, all europeans bear the costs of Germany shortsightedness - as usual - since the beginning of the war in Ukraine.

Since September 2022 Germany imported no gas from Russia.[3] Meanwhile, the nuclear industries of France remains the sole buyer of enriched uranium from Russia in the EU. Admittedly, it has considerably reduced its imports from Russia itself,[4] but is still heavily dependent imports from Russia's sphere of influence (Kazakhstan and Uzbekistan).[5] The same applies to the USA.[6]

> With nuclear, it's pretty clear how to run a grid. Heck, France has been doing so for decades. The question is how to build it cheaply at scale but at least we have some good ideas and experience about how to do that.

I do not deny that it is possible to operate a reasonably stable electrical network with dirty energy, apart from the regular shortages in dry summers and during heavy frosts. But Germany is ambitious and is going to show the world that it is possible to do it with clean energy. The nuclear lobbyists fear most that this will be successful. This is the only way to explain why they are attacking Germany so fiercely, even though they could actually sit back and wait to see if it succeeds. They fear for their business.

[1] https://energiewende.bundeswirtschaftsministerium.de/EWD/Red...

[2] https://www.iea.org/countries/germany/coal

[3] https://www.statista.com/statistics/1332783/german-gas-impor...

[4] https://bellona.org/news/nuclear-issues/2025-01-eu-and-us-re...

[5] https://en.fergana.news/news/137148/

[6] https://www.osw.waw.pl/en/publikacje/analyses/2025-06-18/rus...

Re: Germany outfitted half a million balconies with solar panels

#592

Post by kragen » Mon, Oct 06, 2025, 8:50 PM UTC

ssl-3 wrote: post #252

kragen wrote: post #242

Earlier quoted context omitted.

Possibly you have misunderstood.

Can you elaborate? Which part is it that you think I may have misunderstood? What problem (or solution) is the concern, here?

A hypothetical microinverter is completely capable of kickstarting the "grid" within a single house. You can try it yourself: get a 2000-watt car inverter, connect it to a car battery, turn off your house's main circuit breaker, and plug a suicide cord (male to male) between the car inverter and one of your house's outlets. The electrical appliances in your house will work fine unless one of them starts trying to draw more than 2000 watts (or, as hedora says, unless you're powering only one phase of a split-phase system). This is dangerous: if someone turns the main circuit breaker back on while in this setup, the car inverter will probably be destroyed and may start a fire. But it's far from a technological impossibility. It's achievable even with redneck duct-tape-and-baling wire engineering.

Re: Germany outfitted half a million balconies with solar panels

#593

Post by alexey-salmin » Mon, Oct 06, 2025, 9:01 PM UTC

Slartie wrote: post #544

alexey-salmin wrote: post #525

Earlier quoted context omitted.

30 years lifetime (if there are no heavy storms), 5-10 years to recoup energy, that's 3-6 EROI. Then you also need to include inverters which are energy-heavy. If we're talking of any meaningful scale, then you also need to include batteries because without them panels get shut down during sunny hours lowering the EROI even further. In the end you're lucky if you get EROI of 1.5-3. That's an extremely bad deal. All o…

> Then you also need to include inverters which are energy-heavy. Scientific publications say otherwise. It's quite hard to come by any numbers, but page 11 of https://www.wisdomlib.org/uploads/journals/mdpi-sust/2025-vo... says that typical solar inverters require about 15 MJ/kW of power for their production in total, which would amount to approx. 4 kWh per kW of inverter power. A solar panel square meter produces a…

> > This makes sense in certain situations but presenting this as a green solution or as future of humanity is just delusional.

> which is probably the reason why China installs absolutely HUGE numbers of panels. But according to you, they must be "delusional" over there.

State-run economies get delusional pretty easily, but in this case China is safely on the "makes sense in certain situations" side:

* keep electricity prices low

* invest heavily in nuclear

* install solar within reasonable limits (currently around 8% of the grid)

* for better or for worse they burn more and more coal every year

They certainly don't make insane green commitments and they don't say solar is the future of humanity. I don't like China much, but I don't see how they can fall into "delusional" category according to my criteria above, they have none of it.

Now Germany's policy is the complete opposite of China's, except for the "burning coal" part. Germany killed their own economy over high electricity prices because they wanted to go green, but then somehow they've got almost 2x CO2 emissions per capita compared to France.

If someone says "I sacrifice A to get B", but then never get the B and still lose A, and then insist that the plan was a great success -- he's certainly delusional, that's like the definition of the word.

Re: Germany outfitted half a million balconies with solar panels

#594

Post by MagicMoonlight » Mon, Oct 06, 2025, 9:09 PM UTC

Aren’t these the ones where you plug a live wire directly into the wall socket, with zero hardware to prevent surges or fires?

Not sure it’s a good idea really

Re: Germany outfitted half a million balconies with solar panels

#595

Post by bhelkey » Mon, Oct 06, 2025, 9:15 PM UTC

slightwinder wrote: post #397

walthamstow wrote: post #339

Earlier quoted context omitted.

I'm not German nor do I live there, but I would have thought the legacy of Habeck would be more negative due to his opposition to nuclear.

Nuclear has no relevance in Germany, never really had. The plants barely added any value to the market. When Habeck became Minister, most Nuclear plants were already gone, and the last remaining were phasing out, lacking nuclear fuel and permits. Habeck even gave a permit for the last plants to run some more months, squeezing out even the last parts of fuel as much as they could, just so they could serve as an additi…

> Nuclear has no relevance in Germany, never really had.

In 2011 ~25% of Germany's electricity came from their nuclear reactors [1]. Germany closed their last nuclear reactor in 2023.

[1] http://large.stanford.edu/courses/2019/ph241/noland1/#:~:tex...

Re: Germany outfitted half a million balconies with solar panels

#596

Post by ProllyInfamous » Mon, Oct 06, 2025, 9:21 PM UTC

john61 wrote: post #175

I have cut my warm water costs by 80% with balcony solar panels. I have a warm water heating pump with 600 W electrical power. My little server turns it automatically on when the solar access power is greater than 540 W (measured by the smart meter). This generates usually enough warm water for our household. Also the solar panels cover to idle power of the house of 50-100 W very easily during daytime. This pays off…

The hybrid (heat-pump & heat-elements, both) water heater I installed 2 years ago has already paid for itself in savings. This design literally pulls the heat out of your conditioned space, providing both cooling and dehumidification (I live in a humid temperate rainforest so win-win). During the brief winter months I just set it to heating elements only, and it behaves like a traditional watertank heater (i.e. doesn't cool house in the winter, using only resistive heating).

Re: Germany outfitted half a million balconies with solar panels

#597

Post by subscribed » Mon, Oct 06, 2025, 9:42 PM UTC

mytailorisrich wrote: post #474

jillesvangurp wrote: post #246

Germany did one simple thing (uncharacteristically) which is removing all the bureaucracy here. Just go ahead and do it. It's fine. Cost in the article is cited at 550 euro. I just browsed amazon.de and you can buy complete plug and play kits here in Germany for as little as 239 euro. Most kits are priced between 300-350 euro. I did not see a many kits over 500. I pay about 70 euro per month for electricity. If it sa…

Not obvious that this is "good" for the environment overall, though.

And how that would be bad, specifically?

Considering Germany is still getting 30% of the electricity from the fossil fuels[1], I wonder how that would be a net negative for the environment.

[1] https://www.cleanenergywire.org/factsheets/germanys-energy-c...

Re: Germany outfitted half a million balconies with solar panels

#598

Post by alexey-salmin » Mon, Oct 06, 2025, 9:43 PM UTC

kragen wrote: post #585

alexey-salmin wrote: post #344

Earlier quoted context omitted.

> Your generalization that any kind of decentralization amounts to collective action failure is wrong. Some kinds of decentralization do; ... Others don't. That's correct, yes. I too prefer a decentralized washing machine to coin-operated laundromats which are very common in France where I live nowadays. However I still believe that electricity generation has more in common with steelmaking than with laundry. Today s…

You mean energy payback time? Just on an economic basis we can bound the energy payback time to about four years, and in https://news.ycombinator.com/item?id=45488310 we found a Fraunhofer report by Simon Philipps and Werner Warmuth with a more detailed estimate arriving at a 1.1-year energy payback time in Northern Europe, 0.9 years in Southern Europe: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p...…

> Just on an economic basis we can bound the energy payback time to about four years

If you use electricity prices to make that calculation, you need to take in account that solar panels are produced in China off cheap coal-based electricity. If you produce a panel in Germany it would take much longer to break even economically (if ever). That's what I mean by "enabled by economical disbalances around the world".

> we found a Fraunhofer report by Simon Philipps and Werner Warmuth with a more detailed estimate arriving at a 1.1-year energy payback time in Northern Europe, 0.9 years in Southern Europe

This article doesn't explain how they make their calculations and I struggle to replicate them. The usual estimate to produce a PV panel is 600-1000 kWh per 1sqm. Measured (not projected) yield in Germany is 160-180 kWh per 1sqm per year. A balcony solar panel will yield even less than that because it's not positioned optimally. Then you won't consume all that it produces because you're at work during the day and there are no appliances running except the fridge maybe. In the end you may get anywhere between 10 and 100 kWh per 1sqm per year (would love to see some real measurements by the way, not projected ones).

So my view is very simple: these balcony panels make sense economically because German economy is cooked. However from the physics/ecology perspective they make no sense at all and many of the panels installed today will never recoup the electricity used to produce them, making them a net-negative impact for the environment. Which by the way could be a reasonable price to pay for autonomy in case of power failure but these balcony setups can't run when the grid is off.

Re: Germany outfitted half a million balconies with solar panels

#599

Post by kragen » Mon, Oct 06, 2025, 9:48 PM UTC

martin_a wrote: post #539

kragen wrote: post #96

Earlier quoted context omitted.

Are those retail prices? Are you buying them in a store, or what? 440Wp/60€ is only 0.136€/Wp, which is higher than the wholesale 0.100€/Wp price reported on Solarserver, but only barely. The word "diffusion" does get used in this way in English, but many native English speakers may be unfamiliar with it.

Panels etc. have become really cheap now: https://www.globus-baumarkt.de/p/schwaiger-balkonkraftwerk-8... That's 0,38 Euro/W of panel power, including inverter and cable. And there might be a solid price uptick on that because of the shop that's selling it. Wholesale from specialized shops is probably much cheaper...

Just for the record, that seems to be an 860Wp "Schwaiger Balkonkraftwerk 860 Wp Wifi fähig" for €325, "inkl. gesetzl. MwSt.", but not including "Versand- & Lieferbedingungen + 99,99 € Versandkosten". So it's €424.99, which is €0.494 per peak watt, about five or ten times the wholesale price of just the solar module.

Re: Germany outfitted half a million balconies with solar panels

#600

Post by martin_a » Mon, Oct 06, 2025, 10:56 PM UTC

kragen wrote: post #599

martin_a wrote: post #539

Earlier quoted context omitted.

Panels etc. have become really cheap now: https://www.globus-baumarkt.de/p/schwaiger-balkonkraftwerk-8... That's 0,38 Euro/W of panel power, including inverter and cable. And there might be a solid price uptick on that because of the shop that's selling it. Wholesale from specialized shops is probably much cheaper...

Just for the record, that seems to be an 860Wp "Schwaiger Balkonkraftwerk 860 Wp Wifi fähig" for €325, "inkl. gesetzl. MwSt.", but not including "Versand- & Lieferbedingungen + 99,99 € Versandkosten". So it's €424.99, which is €0.494 per peak watt, about five or ten times the wholesale price of just the solar module.

Yes, but you could also just drive to one of the roughly 2.000 home and garden markets and just take one of the sets home with you in your car. Or get yourself cables and an inverter and buy the cheapest panels you can find, maybe even used ones.

The thing is: Prices are falling fast and that's great for everybody.