Solarpunk technology

2401 readers

1 users here now

Technology for a Solar-Punk future.

Airships and hydroponic farms...

founded 2 years ago

MODERATORS

[email protected]

117

How Germany outfitted half a million balconies with solar panels (grist.org)

submitted 2 months ago by [email protected] to c/[email protected]

23 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] azertyfun 0 points 2 months 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 2 months 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.

[–] azertyfun 1 points 2 months 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.

[–] [email protected] 1 points 2 months ago* (last edited 2 months 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...

[–] azertyfun 2 points 2 months 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.

[–] [email protected] 1 points 2 months 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

[–] azertyfun 2 points 2 months 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.

[–] [email protected] 2 points 2 months 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!