Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Germany outfitted half a million balconies with solar panels

grist.org

Post reply on HN
Print view View original

581–590 of 651 posts

Re: Germany outfitted half a million balconies with solar panels

#581

Post by StopDisinfo910 »

nmehner wrote: post #567
StopDisinfo910 wrote: post #482

Earlier quoted context omitted.

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…

On short sightedness: https://www.dw.com/en/russian-gas-in-germany-a-complicated-5... "Several commentators, business leaders and academics have identified that 1970 deal as a significant fork in the road of the Cold War, as it established a mutual basis for economic cooperation between Russia and western Europe." There are certainly different opinions on that. Gas imports started long ago and in the cold war that ap…

You are entirely missing the point. The issue is what do you do when you have no renewable because it’s the winter and there is no sun and no wind. German answer to that - like it or not - is building gas fired power plants and using coal in the meanwhile. That and buying a ton of nuclear energy from France a fact you are conveniently forgetting.

The ratios you quote are meaningless. The issue is that it can’t scale so as to fully decarbonise the grid. Thankfully the current German government seems to finally have seen the light.

Re: Germany outfitted half a million balconies with solar panels

#582

Post by kragen »

pfdietz wrote: post #381
kragen wrote: post #172

Earlier quoted context omitted.

As I understand it, their market is dependent on it. They can't store electrical energy, only thermal energy, and their system is designed to store it at fairly high temperatures (they don't say explicitly, but I'm guessing 800° and up from the problems they report having to solve) which you can avoid doing if you're just targeting the process heat market. So turning their stored heat back into electrical energy is n…

No, their market is not dependent on it. Generation of power from stored thermal energy is significantly different from directly using solar: it is completely dispatchable. As such, it serves a role even in a situation where most solar energy (or most solar + wind) is used directly. It enables solar to be used in places, like at high latitudes, where it is otherwise strongly disadvantaged by seasonality (something ba…

Generally speaking, steam circuits have large thermal masses, resulting in ramp-up times measured in hours, so most thermal energy is nowhere close to "completely dispatchable". Completely dispatchable thermal power is internal combustion engines (diesel or Otto) and open-cycle gas turbines, and Standard Thermal is not targeting temperatures high enough to operate those machines. Adding Standard Thermal to a baseload coal plant will not make it dispatchable; you will still have a baseload plant, not a peaker. It just won't consume coal.

I agree that it would make solar usable in situations where it would not otherwise be usable, and high latitudes are a good candidate.

For reasons like these I do not think that they will result in a cost reduction.

Standard Thermal has been bending over backwards to store their heat at the high temperatures I mentioned, resulting in a lot of engineering challenges that a lower-temperature thermal store (say, 400° or below) wouldn't have to deal with. For the most part, process heat is lower in temperature than 400°, so I think that isn't their market either.

Re: Germany outfitted half a million balconies with solar panels

#583

Post by lenkite »

micwag wrote: post #573
Scea91 wrote: post #526

Earlier quoted context omitted.

Right at this moment Germany's electricity mix has 364gCO2eq/kWh carbon intensity, France is at 21. That is because 37% of Germany's production comes from gas and coal. Even from an environmental standpoint, France is doing much better than Germany and that is thanks to nuclear. Also, by closing operating power plants, Germany weakened European energy production at the time when we geopolitically need it the most. ht…

> Also, by closing operating power plants, Germany weakened European energy production at the time when we geopolitically need it the most. Ironically that was France which needed to shut down a lot of its nuclear reactors in 2022 and 2023 due to repairs. So according to your own logic France "weakened European energy production at the time when we geopolitically need it the most." Here in Switzerland the reason give…

Looks like that maintenance did a LOT of good. In 2024, France’s net electricity exports (gross exports - imports) reached ~ 89 TWh, a record.

France's total nuclear generation was ~ 361.7 TWh in 2024. It is expected to be even above that in 2025.

https://www.argusmedia.com/en/news-and-insights/latest-marke...

France is currently the nation that exports the MAXIMUM electricity in Europe.

Re: Germany outfitted half a million balconies with solar panels

#584

Post by kragen »

slow_typist wrote: post #295
kragen wrote: post #248

Earlier quoted context omitted.

It wouldn't be an upper bound if energy were free , but it isn't. https://worldpopulationreview.com/country-rankings/cost-of-e... lists China as US$0.08/kWh, but that's the residential price; industry pays a bit more. But it's a countrywide average. Intensive investigations of Chinese "subsidies" from the US Department of Commerce have come up with embarrassingly little. The current €0.100/Wp price level (12¢/Wp) com…

Process energy will still be a lot cheaper than .08 US$/kWh in China. I doubt they process glass with electric ovens. OTOH that is primary energy then, which kind of supports your argument. Still other emissions in the silicon supply chain that cause global warming are also relevant. If I find the time, I‘ll look for recent LCA.

I'm delighted to see Fraunhofer's report! I'll read it carefully.

You are probably right about the glass. Processing glass in electric furnaces has been a well-established technology for many generations, but it is more expensive than fossil-fuel-fired furnaces, and is used for making more expensive kinds of glass. But the glass in solar panels is an especially cheap kind of glass.

Coal is probably the cheapest form of energy. https://www.coal-price.com/ says that currently in China coal is on the order of US$100 per tonne. Coal has up to 33MJ/kg, so that works out to 0.3¢ per megajoule, or 1.1¢ per kilowatt hour, or more if the US$100/tonne coal isn't the best anthracite. You probably can't literally run a glassmaking furnace with a coal firebox, because of the contaminants from the coal, but you almost certainly can't run it on cheaper energy than that. If 100% of the cost of the solar panels were coal energy instead of electric, that would extend my upper bound out from 7 months to a bit over 4 years.

This seems to be in rough agreement with Fraunhofer's more informed estimate that you cite.

Re: Germany outfitted half a million balconies with solar panels

#585

Post by kragen »

alexey-salmin wrote: post #344
kragen wrote: post #264

Earlier quoted context omitted.

Around here I have a backyard washing machine, a backyard grill, a backyard clothesline, and my neighbors have backyard childcare, backyard parking, and a backyard motorcycle. And actually inside my house I have a flush toilet and an oven. Your assertion seems to imply that if instead I had to wash and dry my laundry at a coin-operated laundromat, eat at a cafeteria table with all my neighbors, and piss in a portapot…

> 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...

Maybe you can explain in more detail what you mean by "enabled by economical disbalances around the world and not by their long-term value", but on my assumption that you're talking about EROEI and energy payback time, your assertion is profoundly incorrect.

Re: Germany outfitted half a million balconies with solar panels

#586

Post by kragen »

stronglikedan wrote: post #553
kragen wrote: post #149

Earlier quoted context omitted.

In the US? Where do you buy it from, and are we talking about a system that feeds power back onto the grid?

Not an answer to your question, but I was amazed at how wildly varied the pricing was when I was getting estimates. This was a few years back and I didn't go with it at the time, so I forget what the exact estimates were. But I remember that the highest was literally double the price of the lowest for all the same equipment. All I'm saying is don't trust any pricing you get from folks online, and do get a lot of esti…

Probably prices now are much lower than they were a few years ago, since solar modules are now at a historically low price that is one third of their price in early 02023.

Re: Germany outfitted half a million balconies with solar panels

#587

Post by kragen »

fweimer wrote: post #347
kragen wrote: post #139

Earlier quoted context omitted.

For many years I have been writing about how bad Germany is for solar panels because of, mostly, how far north it is. Specifically, the capacity factor for utility-scale solar in Germany has historically been about 10%, which is mostly because of the unfavorable latitude and cloudiness. You can see this quantified at https://solargis.com/resources/free-maps-and-gis-data?locali... . The capacity factor for utility-sca…

To put the 700 km² in context, that's approximately 30% more than what is currently (not historically) used for lignite mining in Germany: https://www.cleanenergywire.org/factsheets/germanys-three-li...

Holy shit, I had no idea.

Re: Germany outfitted half a million balconies with solar panels

#588

Post by kragen »

shellfishgene wrote: post #293
kragen wrote: post #80

Earlier quoted context omitted.

Is it discouraged so hard that you can't get it at all? I'd think it would be pretty hard to keep people from importing solar panels from Vietnam or Thailand—although of course you'd probably have to put it somewhere that surveillance drones could see it, if you want it to get any sun. (In that case, if you have a rooftop, maybe you could put it under a frosted-glass skylight.) If anything, I'd expect the prices to b…

https://www.tokopedia.com/ is the Indonesian Amazon. You can get everything it seems, also grid-tied inverters, but the prices are higher than in Europe from a quick check. Probably import taxes.

Thank you very much!

Re: Germany outfitted half a million balconies with solar panels

#589

Post by kragen »

adrianN wrote: post #416
kragen wrote: post #279

Earlier quoted context omitted.

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…

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

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.

Re: Germany outfitted half a million balconies with solar panels

#590

Post by benjiro »

chickenbig wrote: post #487
benjiro wrote: post #420

Earlier quoted context omitted.

Those 3 plants had been running on "deferred maintenance" as the plant shutdown was planned years ago. Keeping the plants open will have resulted in a ton of money to maintain the safety of the plants going forwards. This was one of the biggest factors in the shutdown. Even if the plants stayed open, multiple reactors needed maintenance (and thus shutdown of those rectors). Remember, they kept the open even longer th…

> Those 3 plants had been running on "deferred maintenance" as the plant shutdown was planned years ago. They had > 95.4% unit capability factor in 2022 per https://pris.iaea.org/pris/WorldStatistics/ThreeYrsUnitCapab... . It doesn't sound like they were being run into the ground, rather things were operating very efficiently. > Keeping the plants open will have resulted in a ton of money to maintain the safety of th…

> They had > 95.4% unit capability factor

That is not the issue. Let me give you a example. Belgium decided to extend the life on several nuclear reactors, that originally had plans for decommissioning.

So they started to do actual deep maintenance for the extended life. Then they ran into issues of cracks in the concrete, issues with cracks in metal storage tanks, and a whole lot of other issues.

Reactors down for a long periode for the repairs, AND a ton of extra costs. These costs of those repairs, i can not find them no matter where i look. Its interesting how hidden those are.

For the 2025 extension, the initial estimated 1.5 billion for the life extension. And still the whole issue about the reactors issues their full fix cost price is unknown. In other words, they did a patch job and for the next extension, they need to do a major maintenance / repair.

The extension of the German reactors was estimated at 3B+ if i remember correctly. And that does not include if any issues are found.

That is the problem... This type of deferred maintenance start to stack up over time, when you have a phase out time for reactors. So issues becomes a big black money hole when you already committed to the extension.

Post reply on HN