13h ago

‘If 1.5m Germans have them there must be something in it’: how balcony solar is taking off

www.theguardian.com ‘If 1.5m Germans have them there must be something in it’: how balcony solar is taking off

Balcony solar panels can save 30% on a typical household’s electricity bill and, with vertical surface area in cities larger than roof space, the appeal is clear

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2mo ago

‘If 1.5m Germans have them there must be something in it’: how balcony solar is taking off

www.theguardian.com /environment/2024/dec/18/if-a-million-germans-have-them-there-must-be-something-in-it-how-balcony-solar-is-taking-off

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2mo ago

‘If 1.5m Germans have them there must be something in it’: how balcony solar is taking off

www.theguardian.com /environment/2024/dec/18/if-a-million-germans-have-them-there-must-be-something-in-it-how-balcony-solar-is-taking-off

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2mo ago

‘If 1.5m Germans have them there must be something in it’: how balcony solar is taking off

www.theguardian.com /environment/2024/dec/18/if-a-million-germans-have-them-there-must-be-something-in-it-how-balcony-solar-is-taking-off

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78 comments

“Plug-in solar is part of the whole array of options,”
I don't understand how this works? For our system we need an inverter that cost about $3000.- (half if it doesn't have to handle a battery), and it needs to be installed by an authorized electrician.
For a small system as the one shown, the price of panels are peanuts, the 2 panels shown should cost less than $150 combined. While the cost of inverter and getting it connected is way way higher. There's a lot more to this than not being on the roof!?! But which isn't disclosed.
The article says nothing about how the power from those panels is made usable.
- Balcony solar is a set of diy technologies that require no utility permissions.
  In Germany, NL, you can just plug it into socket and it works somehow.
  In us you can use powerstations and also adapters that sync draw from battery as it charges from ac in house.
  It pays for itself even with more expensive equipment, by not needed license, permission, that can lead to cheap efficient panels costing over 3$ per watt. Small systems that just offset use instead of selling back, have higher revenue offsets in high per kwh priced markets.
- There are two main inverter approaches. One big inverter that takes the DC from a bunch of panels and converts it into AC and micro inverters where each panel gets it's own small one placed directly under the panel.
  The micro inverters cost around $150 each. So you need around 10 panels before the single inverter becomes a good choice.
  Installers love the micro because the install is easier. However as a owner with say 30 panels you now have 30 points of possible failure instead of the 1.
  
  Oh boy, apparently there's a lot I don't know. It's really cool there are those cheaper options now.
- The "balcony" bit isn't the defining characteristic, it shouldn't be taken literally. Some people do have their "balcony solar power" on their roofs.
  What defines it is limitation to 800 W and inverters that come with a normal Euro Type F ("Schuko") plug and no legal requirement for professional installation. A layman can literally plug it in to an existing wall socket. Given that they are capped at 800 Watts, the inverters are also the simplest type and dirt cheap (although often they are literally just software-capped and identical to higher power ones, make of that what you will). Complete systems (2 panels, cabling, inverter) cost between 299€ and 800€ depending on quality. You genuinely only have to buy a fixture that suits your needs and a mate to help you install it.
  Proper several-Kilowatt-systems are very expensive in Germany too.
  
  Thanks really good info. 👍😀
  A layman can literally plug it in to an existing wall socket
  That's amazing, I had no idea that is possible??? Is that special for Germany? (sorry for keeping on with new questions). 😋 I've never heard of that option here in Denmark.
  cost between 299€ and 800€
  No wonder it's a popular option, our system is of course bigger with 11.2 kWh and 7.5 kWh battery. but it was $17000 1½ year ago. Prices have dropped to $12500 for a similar system, but still such an 800W system is dirt cheap by comparison.
  
  I had no idea that is possible??? Is that special for Germany?
  I mean, the regulation seems to be, but there's no fancy tech going on. I'm not an electrician but I think I can explain, as I have recently tried to understand myself. To understand why it's possible it's best to understand why the limit is at 800 W precisely.
  So German wall outlets usually have a 16 A fuse and the wiring in the walls is dimensioned to accommodate slightly higher current (I think they are 2.5mm² gauge allowing up to 20 A but don't quote me on that particular part) for safety reasons. I suppose it would be the same or very similar in Denmark, or maybe most of Europe that uses 230V/50Hz AC.
  Now, normally, if you have dangerously powerful load that would melt your wires, let's say 5 kW, and you plug it in to an outlet the fuse will just pop and you're safe. If however you have a 2 kW PV system connected to a wall outlet nearby, it would theoretically be possible that your 5 kW load draws 13 A (3 kW) from the mains through the fuse and another 8.7 A (2 kW) from the PV system over the same wire in the wall that is only rated at 20 A but now carries 21.7 A. And the fuse would never pop at 13 A, making it a huge fire hazard. 800 W is basically just what will always comfortably fit into the safety margin of the wiring in German houses. All systems above 800 W need to be hardwired by professionals "behind" the fuse box so that every Amp from your PV goes through a typical 16 A fuse.
  still such an 800W system is dirt cheap by comparison
  Absolutely. I guess the low threshold for installation allows some kind of mass market economy of scale whereas systems like yours are homeowners' luxury goods.
  
  Great post! Thanks for doing the math and explaining the concepts!
  
  There are already a few requirements for operating the balcony panels, At least here in Germany:
  You need a suitable electricity meter
  You have to register with a relevant authority and inform the electricity provider that you are operating a “balcony power plant”.
  The microconverter should run on its own secured circuit. (“Should”, will certainly do very few) But technically it is simple:
  Set up panels
  Connecting necessary plugs
  Microconverter to the socket
  Be happy that you produce up to 800 watts of your own electricity
  I think it's almost irrelevant how many panels you ultimately split up. However, no more than 800 watts may be fed in.But if you have panels with, let's say, 2000 watts, you can of course charge various batteries with them beforehand. Nobody can say anything against it.
  
  You need a suitable electricity meter
  That makes sense, we also needed new meter, and that was about €200.- with installation. Not a big deal for a big installation, but for a system that can cost only €300.- an extra 200.- would be pretty significant.
  
  Just for your information : belgium is allowing the balcony solar panels this year, but they have put limits on which you can install. The power supplier needs to have approved the kit you install. This is just to prevent people from getting cheap crap from the internet.
  Other than that, same rules!
- If you pay 3000€ for an inverter then that's probably included installing and whatnot. You can get a cheap 50€ 4kW inverter on aliexpress, or an expensive 500€ 10kW one.
  
  No the price was not including installation, We have 11.2 kW panels and 7.5 kWh batteries. Installation was almost $5000.- !! That was probably mostly the 28 panels on the roof. But we had one installer handling everything, who was also responsible for the electrician.
  
  That's a massive installation though! Wow!
  Also, you got a biig roof!
  
  When we bought the house, that was one of the parameters on our list for "the perfect house". So the roof to the garden is also almost perfectly towards the south. 😀
  Even in January we've made 41% of our power consumption from the solar panels. 😎 You are right that it is a bit oversized according to "normal" recommendations which are 8 kWh for a house the size of ours, but we went a bit bigger in preparation for air to water heat pump, so warming the house will be electric, (currently wood pellets), and also we plan to buy an electric car within the next 2 years.
  Also it was a bit for fun, because of the movie spinal tap, so our panels go to 11 instead of just 10, because we need that little bit extra. 😋
- Have a look here: https://en.m.wikipedia.org/wiki/Balcony_solar_power
  
  OK thanks, so they are indeed complete systems including inverter, so it can be connected to the grid.
  I suppose they've made some cheap low power inverters then, but the power still needs to have stable voltage an frequency and synchronization. So I wonder how cheap it's possible to make?
  I also suppose it still needs an authorized electrician to connect it? Unless Germany has some fancy system that is prepared for "plug in" connection of a local power source.
  
  In the EU, as long as it's under 800W it can be plugged directly into an outlet in your home without any kind of installation, back-feeding the grid that way.
  You're not getting paid anything for the power you send back into the grid so anything you don't use you lose.
  
  Still very cool, because selling surplus power is almost completely worthless anyway. (at least it is here)
  In the summer when you can sell, prices are generally extremely low, we have sold about twice what we use, but the value of selling is only about 5-10% on average, compared to the savings of using it ourselves. That's because the price often drop to close to zero in the middle of the day, and sometimes even below.
  Electricity itself is dirt cheap, the reason the prices are high are transportation and taxes, and short peak prices in the evening. Here transportation alone is more than the electricity itself during winter.
  And we are only paid the pure electricity price here, which I suppose is the case most places.
  
  It literally plugs into the wall.
  
  That's amazing. 😀
- I wonder if a whole building could use one or two inverters?
  I feel that'll make the cost reasonable
  
  For apartment buildings I don't think that's possible, since electricity is a per household connection with separate meter.

78 comments