Waldo JaquithThis is brilliant. In Germany, it's popular to buy €200 solar panel / inverter combos that plug into a nearby power outlet, feeding the power back into the grid, running their power meter backwards. "Installation" just takes a minute. Folks in apartments simply hang them from their balcony “like wet laundry.” Over 500,000 have been sold. With power at €0.25/kWh, the payback time is about 27 months—after that, it's just free electricity. https://www.nytimes.com/2024/07/29/business/germany-solar-panels-climate-change.html?unlocked_article_code=1._E0.zL83.1FCeoxOrFDBY&smid=url-share
Peter Griesar@waldoj this company has beem around a while in the US. https://legionsolar.com/getStarter.html
@griesar What we need is for Costco et al to sell 200 watt panels that people can put in their cart, take home, and plug in.
Samhain Night@waldoj this company is on Amazon now, but point taken. I wonder if a regulatory issue is why there isn’t a market selling these at Costco.
@griesar I’d love to know how this prevents back-feeding into the grid when the grid goes down, to prevent electrocuting the repair crews. The product doesn’t mention that, which is troubling!
Sim@waldoj that guy in the video has a lot of standing water on that flat roof!
@sim I was also concerned about this
robloblaw
Osunderdog
Brooks Davis@waldoj sounds like an exciting place to be an electrician…
Nonya Bidniss 🥥🌴@waldoj AYFKM and I recently heard that people in CA are paying, PAYING, the local utility because they are feeding back into the grid with their massively expensive solar installations.
Phil Landmeier@Nonya_Bidniss @waldoj Big corporations make the laws through their lobbying efforts. The electric utilities want to maintain their business model.
Ian Dees@waldoj at https://www.reddit.com/r/SolarDIY/comments/yj6kdo/balcony_pv_in_the_us/ they say:
> Balkonsolar is probably OK in Germany because the lines are buried and they don't have unexpected outages. Plus I believe the (required!) meters are regulated and won't feed the grid if no grid voltage is detected.
Very German
Andreas
vampirdaddy@ian @waldoj
There are very rigid requirements for the shutoff times (<10ms), residual voltage drop (30ms to below 10V or so, from memory) and two redundant shutoff mechanisms (at least one with physical disconnect).
PowerOn / reconnect must wait at least 10s (IIRC), but has to be randomly spread over 5min after stable mains connection to prevent feeding spikes after an area outage is resolved.
There are norms for that in Germany (of course) 🤓
Nelson Minar
Kevin RussellPayback for two is just 27 months as well, payback for three is still 27 months.
Only one world saved.
zl2tod@waldoj
Running electricity meters backwards only works reliably with old electro-mechanical power meters.
Most modern electronic meters not so much.
Local generation will offset your electricity usage though.
Running electricity meters backwards only works reliably with old electro-mechanical power meters.
Most modern electronic meters not so much.
Local generation will offset your electricity usage though.
Matt Godden@waldoj meanwhile, in Australia it’s against the law to make your own Ethernet patch cables, unless you’re a licensed electrician.
BavariaNephro@waldoj @pkreissel small correction from germany: you‘re not allowed to run your meter backwards.
Philip Kreißel@BavariaNephro @waldoj With the new law you can run it backwards for a limited time. I also never heard of anyone who got problems because of it.
isbjørn@waldoj
just a few words from germany:
Typical electrical installations in German homes are fused with 16A, while the cables allow a load of 20A or even 25A. So, there is a reserve of at least 4A.
Balcony power stations (BPS) with (soon) 800W are therefore permitted, as they can feed in 800W/235V => ~4 A current.
If more powerful BPS were installed, more current could also be drawn on one circuit, but then the cables would blow instead of the fuses in the event of an overload.
/1
@waldoj
The current regulation also provides for the installation of a special “Wieland” plug [1] so that the contacts cannot be touched. In addition, the inverters must switch off if they cannot find any mains power, i.e. if they are not plugged into the household grid.
But -- quite honestly -- most BPS probably run without an electrician having connected them, most of them have not been registered and some probably have a significantly higher output 👼
[1] https://m.media-amazon.com/images/I/516f1-TM9PL._AC_SL1500_.jpg
/2
@waldoj
From a purely technical point of view, it would certainly be possible to connect BPS with a higher output if they were connected directly and via a separate line to the domestic power distribution system -- but this is not permitted in Germany, or would then be a “normal” PV installation with all the usual requirements.
I don't know the details about the US, but I suspect that the electrical system differs significantly from that in Germany (not only because 110V instead of 235V)
/off
@waldoj
/addon
Some fuses are also only designed for 10A, so there would be a larger reserve if the more capable cables are installed (probably not) -- to be on the safe side, however, only 800W are permitted.
I also remembered another point in favor of the “Wieland” plug:
The ordinary “Schuko” socket is only designed for 10A continuous load, it only has to withstand 16A for 10 minutes :-)
/off^2
diesUndDasMitTassen 🇺🇦@waldoj "Reverse rotation" only happens if it is an old mechanical meter. However, many new digital meters have been installed in recent years (they shall all to be replaced). These new meters measure feed-in and consumption, and count it up. If you are using a so called balcony power station with only 600Wh (a new law will allow 800) and not consumpting all energy produced, you will give it away to the grid.
tessarakt@waldoj Well, the meter only runs backwards if the operator does not exchange it.
Felix Frank@waldoj this is spotty second hand knowledge from a friend who lives outside the city: He has lots of PV, but technically he is supposed to register them now, at which point they will install a special meter. The „just run it backwards“ still works, but is frowned upon by regulators.
Richard "RichiH" Hartmann@waldoj not quite. It will usually take you an hour or so in the trivial case of putting it into the balcony. That will give you really bad returns though.
Installing the panels on the outside requires proper installation, wind load consideration, etc. An average glass panel weighs 35kg, which can easily kill or maim if it falls on someone.
The incoming new law will privilege these installations so landlords can't do much any more as long as they are installed properly.
@waldoj importantly, proper installation won't require professional installers. The point is currently fuzzy in law, hopefully it will be tightened, or else some courts will need to clarify.
I expect newer sets on the market to come with certificates for X amount of load, and that load being higher than some same worst case. That would allow for layperson installation and high confidence in things being proper.
Beni@waldoj The concept is beautiful, unfortunately one has to register those "balcony power plants" and then one gets a power meter that cannot run backwards. Thus, when legally used, most of the energy goes to the grid for free.
deBaer@waldoj This is mostly correct. But there are just a few legacy meters left that can actually run backwards. Most meters either just ignore power going back to the network, or they count it separately, but there's no claim to get paid for the surplus power. It's basically a mandatory free gift you're giving to your power network provider monopoly.
@deBaer @waldoj
It’s not a mandatory gift.
You can choose for a simple plug & register (and nothing after that).
That’s the go-easy Balkonsolar approach. No hassle, but also no pay.
or
You register energy production as (side) business and have a proper, full, formal electric installation and accounting processes.
In the latter case you get compensated (quite decently) for the generated electricity.
Martin@vampirdaddy @deBaer @waldoj
I get 0,079€ per kWh I feed into the grid, but have to pay a fee of about 12€/year .
I buy from the grid for about 0,40/kWh.
So, will I feed enough to bring in at least 12€?
The real bonus is having not to buy from the grid.
I get 0,079€ per kWh I feed into the grid, but have to pay a fee of about 12€/year .
I buy from the grid for about 0,40/kWh.
So, will I feed enough to bring in at least 12€?
The real bonus is having not to buy from the grid.
Lord Tom Klopf of CZ 
@waldoj are there any examples of vendors doing this? I couldn’t access the article. Thanks !
@waldoj wait, what? It just... works?
tf@waldoj @simon_brooke they will have to clamp down on this sooner rather than later, feeding electricity back into the grid in such a way is a disaster in waiting for grid stability, cheap inverters aside, domestic solar generally only provides electricity back to the grid when the grid doesn’t needed it, which leads to overloading it, so the ‘buy-back’ must be controlled centrally by the grid. 500k installations in the context of Germany is nothing, and it doesn’t scale.
Simon Brooke@tf @waldoj Or the make the grid resilient to it, as we were doing at Smarter Grid Solutions (yet another of Scotland's great companies which have been bought out by foreign capital).
This isn't rocket science.
DERMS software for utilities and asset owners and operators | Smarter Grid Solutions
Smarter Grid Solutions is a software company providing DERMS that delivers extremely fast, highly reliable and fine-grained control. With global live systems working 365 days a year for some of the worlds largest utilities.
@simon_brooke @waldoj not what this is though, is it? This is just people plugging random inverters into the mains socket. Rooftop solar is of course workable, and one of the better options, but not this way. But perhaps it demonstrates that the official rooftop installations are priced with huge profit markups.
@tf @waldoj well, exactly. And it really wouldn't cost much to mandate a standard protocol that such devices must implement which would allow them to be selectively switched on and off in real time as loads on upstream transmission lines varies. That's essentially what's done with commercial solar farms and wind turbines, and it's only a little bit more (probably #OpenSource) software to add to the existing controllers.
The_SunAustralia leads the world in roof top solar. There is a lot of solar being feed back into all across the grid.Some days Rooftop solar has supplied 101% of South Australias demand.
Most Australian grid inverters just shut off if the line voltage is above what is allowed and do not have any other central control. With out problems Only in the last few years have new inverters have had to be able to be turned off to help in the rare case of system instability.
Martin Marheinecke@waldoj
Such balcony solar systems can be very useful even without a grid connection - for example to operate an AC. And it is really uncomplicated and inexpensive, you can buy them not only in specialised shops but sometimes even as a special offer at Aldi or Lidl.
Such balcony solar systems can be very useful even without a grid connection - for example to operate an AC. And it is really uncomplicated and inexpensive, you can buy them not only in specialised shops but sometimes even as a special offer at Aldi or Lidl.
Michael@waldoj My neighbour literally just had 3 of these installed on the rear of their house, as it's south facing and catches the sun almost from dawn to dusk. I'd love to have some myself, but our house is the German equivalent of Grade Listed, and we aren't allowed to fit them.
@waldoj Also worth noting that many more of us would do proper full on solar installations, but the government has, at every step, made it impractical, or financially ruinous to do so, because they seem to have a permanent erection for coal still, especially here in Bavaria.
2¢@waldoj how do they manage backfeed hazards?
Christian Tietze@waldoj what do you mean, power at 0.25 EUR/kWh :) We still pay 37¢
@ctietze I'm just repeating what the article says. ("Electricity prices in Germany jumped after Russia invaded Ukraine, and have now settled at around 25 euro cents per kilowatt-hour. But they remain among the highest in Europe.") I've got no special knowledge of your power rates. :)
@waldoj I just read the article, and I'm even sadder to hear that 25¢ was considered to be expensive
Good thing is our solar panels will payback even sooner 🥲
Florian Schmidt@waldoj
That's right, many cities even subsidize the "balcony power plants" to become more resilient, driving down payback time even more.
There were many fights with German technology angst though (and powers that be), @balkonsolar has much background info on this.
That's right, many cities even subsidize the "balcony power plants" to become more resilient, driving down payback time even more.
There were many fights with German technology angst though (and powers that be), @balkonsolar has much background info on this.