this post was submitted on 28 Sep 2024
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Solarpunk technology

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[–] [email protected] 18 points 1 month ago (2 children)

It's often said that probably the biggest challenge with switching over all the cars and heating to renewables here in Germany, is going to be the transport of so much electricity to all the homes.
That's what I also really like about the balkonkraftwerk, that it produces electricity right where it's used.

[–] DacoTaco 7 points 1 month ago

I agree. I often discuss this with friends and the argument of "our electricity network cant supply all that power" (which is true) is one i often counter with adding more solar panels, even to apartments.

[–] [email protected] 2 points 1 month ago (2 children)

Where but not necessarily when it’s needed. Still it’s good to connect to grid through a wall plug, without expensive or permanent equipment.

[–] [email protected] 4 points 1 month ago

There are now small scale storage systems available to flatten the curve of production and increasenlocal consumption.

[–] [email protected] 3 points 1 month ago

The idea for the when-part is that people will have electric cars at home, which can double as a big battery, or as the other guy already said, you can buy dedicated storage, too.

You could also hook these storages up to the grid, and then have an algorithm decide to sell to the grid when electricity is expensive, or to charge from the grid while electricity is cheap, possibly even taking the weather forecast into account.
Definitely still lots of details to figure out, but I expect things to head that way...

[–] DacoTaco 12 points 1 month ago* (last edited 1 month ago) (3 children)

My brother, who lives in germany, has told me about this before and i love the idea so much. Its so simple to implement and has no downsides whatsoever. The person renting the appartment buys the solar panel and if they leave they can easily take it with them.

And yet, i can not for the life of me get my land lord convinced to allow me to do this too despite it needing no permanent changes to the apartment... Solar panels rules are too strict here too, and i love that germany just embraced them like its nothing

[–] [email protected] 10 points 1 month ago (2 children)

Yet, some landlords refused it. There have been talks about a new regulation, but currently a landlord can more or less arbitrarily deny solar panels.

My "landlord" is a company owned 100% by the city I live in, they claim to embrace solar, but in order to get the permit to install a panel I need a structural review of the balcony, which a) costs a ton of money and b) I need some documentation (blueprints/plan) from my landlord. So far that sounds kind of reasonable, buuuut they refuse to give out any information about their buildings, so even if I would pay someone to prove the balcony won't collapse, this guy can't finish the report without knowing what the wall is made of.

So effectively, they managed to pull ye olde Kafka not-really-denial.

[–] scrion 9 points 1 month ago* (last edited 1 month ago) (1 children)

If you are talking about Germany, that is no longer true - landlords can not deny installations without sound reason:

https://www.tagesschau.de/wirtschaft/verbraucher/balkonkraftwerke-mieter-gesetzesaenderung-100.html

The surrounding laws were updated July this year, so it is a recent change.

[–] [email protected] 10 points 1 month ago (1 children)

If your balcony collapses due to 800W worth of solar it'd also collapse due to a couple of planters or a fat friend coming over so I guess you should take such worries as an admission on their part and withhold rent until they prove that the balcony is safe to use.

[–] scrion 1 points 1 month ago (1 children)

I think you might have replied to the wrong comment.

[–] [email protected] 2 points 1 month ago

Yes and no, I think withholding rent is a quite German thing (or, rather, courts siding with you when you do it) and "it's not structurally sound" sounds like a thing rabidly anti-solar landlords would come up with to get around the law.

[–] DacoTaco 1 points 1 month ago

typical hehe
governments are often more strict in rules than normal people, and those rules often prevent other rules from being enforced hehe
it shouldnt be though, they should set the bar with their own buildings :)

[–] [email protected] 1 points 1 month ago (1 children)

You can safely feed in a lot more than 800 W if you know what you're doing, but it's illegal.

[–] [email protected] 2 points 1 month ago (1 children)

It's not illegal you need to talk to your utility. For one, they probably want you to produce three-phase.

[–] [email protected] 1 points 1 month ago

I am talking about simple plug-in Balkonkraftwerk. Larger PV installations are a different regulation framework, and need to be signed off on by licensed professionals. Much more expensive, mich longer ROI.

[–] [email protected] 0 points 1 month ago (2 children)

It's only fine because the panels do not do much of anything.

When large swaths of the population become even partially self-sufficient, it's an enormous issue for the electric grid. Again, not an issue over an occasional few hundred watts, but when whole neighborhoods cover their roofs in solar panels the following happens:

  • These (comparatively rich) people stop contributing to maintaining the grid. Half of electricity costs are distribution costs, so unless you have no net metering and a separate distribution line in your bill the rich are being subsidized by the poor to install solar capacity at home. Of course changing the billing system fixes that, but it also makes solar much less financially interesting and really pisses off people who already paid for solar and now won't be having a positive ROI for an additional decade.
  • The panels are not remotely operable so their aggregate power generation sometimes causes enormous stress on the rest of the grid, forcing old nuclear/gas/coal PP to spin up and down much more quickly and frequently than they were designed for.
  • Locally the voltage fluctuations may be very large. Nominal where I live is 230 V, but it's not unheard of for rich neighborhoods to be pushing 250 V on very sunny days. Then the inverters shut down automatically, but it's always whoever happens to have the most sensitive inverter who ends up not being paid on sunny days.

Anyways apartment solar is not really the issue here, it's the people with 10+ panels. But there are good reasons for solar to be heavily regulated.

[–] [email protected] 3 points 1 month ago (1 children)

There's plenty of fixed fees in German electricity bills, on top of that the Wh price contains infrastructure levies. As the network changes so will the mix between fixed and consumption-based prices.

That said yes the Green party and its core voting demographic are notoriously bourgeois. "Let them install heat pumps" they said, caressing the one they installed, completely ignoring that at scale district heating is much more sensible. Their non-bourgeois core voters (the ones with a permaculture garden in the countryside) will then defend that by "but we don't want centralisation" MFs municipality-level is not centralised.

[–] [email protected] 1 points 1 month ago

I was thinking of other countries where the billing system has only variable fees. Which used to work when you didn't have many people who are dependent on the grid but have a (almost) net zero power bill.

[–] DacoTaco 1 points 1 month ago* (last edited 1 month ago) (1 children)

thanks for those very interesting points. its great to know those.
i do believe the point of the power grid is changing, and its point is changing. and yes, many people dont like it because they have to pay more despite having solar panels, but somebody has to pay for the maintenance on the power grid and paying those people costs money, lots of it.

i didnt think about the startup time of power plants, but how do they do that now? i cant imagine them being able to do these operations now, or do they really predict power usage constantly? also, i assume the 250v is because putting load on the grid would lower the 250v to the normal 230v, and because people use their solar power that load is reduced so its voltage is too high?

That said, i do believe its regulated too much. It has issues, yes, but regulating isnt making the issues go away...

[–] [email protected] 2 points 1 month ago (1 children)

Yes power usage is constantly predicted by utilities. Production must match consumption exactly at every moment. This means weather forecasting is an essential part of managing a power grid, and doubly so with intermittent renewables.

I think the local overloading has something to do with transformers not being able to handle the massive local overproduction. It's not just power not being consumed, it's power being injected into the grid.

[–] DacoTaco 1 points 1 month ago (1 children)

but it outputs 230v, how would that ever get to 250v? keep in mind, im not an electronics engineer just guessing with what i know

[–] [email protected] 2 points 1 month ago (1 children)

For current to flow out of your house the voltage inside the house has to be slightly higher than outside. Not by much, but a little. So the inverter has a higher output voltage than line voltage by design. If everyone does this and some of the power has nowhere to go, then the average voltage goes up measurably.

This wouldn't be a problem if the grid had been designed to be able to bring power out of residential areas, but my casual understanding is that this doesn't work very well with existing infrastructure, so with a bunch of extra power that has a hard time getting out the voltage keeps climbing until some inverters hit their safety shutoff.

[–] DacoTaco 2 points 1 month ago

Ah ye that makes sense! The grid is pushing 230v in, so to get power out you push harder back, so for example 240v. Thanks!
I know inverters have a safety feature to shutdown if the input voltage is not in range so it doesnt push power on a open net etc. Have had people tell me that inverters doing that was a problem, but discovered they shutdown if the input isnt right!