After only five confusions to the perfect balcony power plant
When a product is sold to customers at a discount store at what feels like cost price, you can assume that it has reached the mainstream of society – nationwide, the numbers have shot up massively since last year. And photovoltaic panels, brackets, inverters and cables are now available for a few hundred euros, and not just at discount stores. “Plug-in solar,” experts call the whole thing.
Legislation follows suit: With the recent adoption of the “Solar Package I” the situation has become somewhat more relaxed for those who would like to take green energy production into their own hands. For example, a digital electricity meter is no longer compulsory, power plants will be allowed to feed in more energy in the future (800 watts are currently only officially tolerated, but de facto permitted and harmless), feeding in is possible with a simple Schuko plug and the required registration in the market master data register has been greatly simplified. Registration with the network operator has not been necessary since spring.
1. Can I now achieve the energy transition on my own with a balcony power plant?
The hope is not entirely unfounded that we will be able to become independent of the discourse surrounding the expansion of renewables, the shutdown of nuclear power and the end of coal. Stefan Krauter, who holds the chair for sustainable energy concepts for the energy transition at the University of Paderborn, is involved with photovoltaics professionally. Krauter completed his doctorate on sustainable energy generation using the sun when most people only knew solar cells from their calculators. Since then, solar energy has become a hundred times cheaper – a watt can sometimes be bought for ten cents. Despite the financial accessibility, Krauter is tempering expectations. He is expecting twenty million balconies in Germany: “If you say that everyone now has a balcony power plant, then we would be at 12.8 terawatt hours. That corresponds to around 2.4 percent of German electricity consumption.” Nevertheless, the small power plants would help to relieve the strain on the grid. And in this way it would be possible to experience the energy transition for oneself. Rather than being felt by society as a whole, the benefits are likely to be felt on an individual basis:
2. Can I save a lot of money?
A high-performance system should cost several hundred euros a year. This means that, given the current market situation, the purchase costs will quickly be amortized. Of course, it depends on the current price of electricity. And, for example, on whether you can, in the best case scenario, do your laundry when the sun is beating down on the panels – the opposite of the old night-time electricity, so to speak.
Of course, the conditions are not always ideal. So let’s be realistic and calculate with the following values: Purchase costs 400 euros, electricity price 35 cents per kilowatt hour, location (important for the hours of sunshine) Thuringia, orientation to the west, installation upright on the balcony, no shading. Anyone who manages to use fifty percent of the electricity generated directly will have recouped the purchase costs in five years. The savings are 92.40 euros in the first year and 924 euros after ten years. At least 634 kilograms of CO2 can be avoided. Okay, complicated calculation with many variables – Feel free to insert your own here, without any math tutoring.
There is no feed-in tariff, by the way. But another idea: “Now, of course, there is the possibility of storing energy so that you can watch the evening news using battery power,” says Krauter. Such batteries make the whole system significantly more expensive, but more efficient in the long term. In general, says Stefan Krauter, it is worth choosing panels of proven quality and not the cheapest, if possible. Then you can expect them to last for many years and at the same time do even more for climate protection. If all of this is not enough for you and you own a property, you should think about a rooftop photovoltaic system. But that is another topic.
3. Balcony power station from the discounter – am I naive? (Or do I have to change the inverter?)
There is no need to condemn the cheap products offered by discount chains across the board, says Andreas Schmitz, but one should be careful. He should know. Schmitz is actually an engineer and research associate at the German Aerospace Center. But his YouTube community of 350,000 subscribers knows him primarily as the “battery doctor,” in which he volunteers to “drive the energy transition a little bit forward.” Despite all his modesty, he and other YouTubers have done a great service to the balcony power plant community on his website. And have addressed what has probably been the biggest balcony power plant problem of all in the past: inverters that need replacing.
Wechselrichtiger – this is actually about security-critical stories, but partly also IT security matters
Dr. Andreas Schmitz “Battery Doctor”
Inverters are the central electronic component of a balcony power plant and convert the direct current from the panel into household-grade alternating current. There are massive differences in quality between a large number of manufacturers and even more brands. Some devices even had to have their operating license revoked. Schmitz and his team have examined a large number of inverters. “These are actually safety-critical issues, but sometimes IT security issues, and sometimes devices that simply don’t work or that break down very often.” In addition, not every inverter can convert the same amount of energy (efficiency) – that would be a shame. Before buying, it is important to look at the manufacturer of the inverter supplied and a Comparison with Schmitz’ online database definitely recommended. It is also worth checking whether the supplied cables are sufficient or whether extensions are necessary. And a look at the supplied bracket is also a must:
4. Yes, will it hold? (And does it have to be a balcony?)
One size fits all may be a dream, but that’s what it will remain, even if the marketing text promises sunny times in terms of installation. In a world with a wide variety of balcony variants, there are also a wide variety of brackets. Whether the one supplied fits is a good question. Try it out, but don’t be sad if you have to reorder it. “I can only recommend spending a few euros more on the bracket,” says Schmitz, “it’s really about making sure it’s stable.” Because in the next extreme weather situation caused by climate change with a tornado or at least hurricane gusts, a loose or unstable panel can pose a serious safety risk. The person from whose balcony it was lost is liable for any damage. Liability insurance is therefore mandatory – and the insurance company should be informed about the system in advance.
Generally, you need to consider where the power plant will do its work, and it doesn’t have to be a balcony. They’re only called that because it sounds so cozy and middle-class. But generally speaking, any surface where panels can be securely attached is suitable. Vertical is best: This makes them less susceptible to wind and more productive in winter. The maximum yield will then be lower, but the electricity will flow more evenly throughout the year.
5. Balcony power plant: Am I even allowed to?
“All areas” also means that balcony power plants can be used to liven up the facades of listed Wilhelminian quarters. This is at least what the Balkon.Solar association expects, because such a system “a) is reversible and b) the visible impact is significantly less than a roof system. In addition, systems for generating renewable energy are privileged.” However, there is no clear legal situation as yet. Not even on the question of whether house owners and landlords can thwart the balcony power project. The go-ahead from the Federal Council is still missing here, but Andreas Schmitz is confident that tenants will soon be able to hang a balcony power plant without permission. The Balkon.Solar association also shares this view. And setting one up inside the balcony is no problem anyway.
Bottomless barrel – funding barrel with a bottom: Important links on the topic of balcony power plants
The closer you get to purchasing your first plug-in solar system, the more questions naturally arise:
- Comprehensive information in every conceivable respect is provided by a kind of balcony power plant primer, now freshly published by Schmitz, Krauter and other experts who as PDF free of charge, Available for donation or in print at cost price.
- Meanwhile, consumer centers are checking what standards and laws currently provide.
- Balkon.Solar is dedicated to the most pressing questions in an FAQ.
- The adult education centers now offer Online and face-to-face courses on the topic.
- And even if the contribution to the energy transition is only small, the partial switch to self-generated green electricity is sometimes subsidized. As is to be expected, this varies from place to place, but confusion is part of balcony power plants: in Saxony, for example, plug-in solar systems receive a flat rate subsidy of 300 euros from the development bank, in Leipzig there is also municipal funding for renters, and even 500 euros for low-income earners. If you have any questions about the funding, Finanztip can help.
