Anyone who wants to install a photovoltaic system today needs patience (and a lot of money): the specialist companies are very busy. But: Can’t you just install the solar modules yourself? We tested it and made a video about it.
transcript of the video
(Note: This is bonus content for people who cannot or do not want to watch the video above. The video track information is not reflected in the transcript.)
Solar panels are super hot right now. A lot of people want some, whether as a small balcony power plant in a rented apartment or a really big one on the roof of their own home. The problem is, it’s very difficult to find people to install it for you. So if you call a photovoltaic company now, for example, they may well say yes, it costs 30,000 euros, but in 2023 we won’t be doing anything anymore.
Does that mean that you have to pay the newly increased electricity costs for a year, even though there is actually still so much space on the roof or balcony? But can’t you just do it yourself? That’s what my three c’t colleagues Jan, Pina and Andrijan asked themselves.
The three of them simply went to the installer and negotiated that they would put the panels on the roof themselves and that the specialist company would only have to check everything and make the connection at the end. He wanted 700 euros for it, which is okay for work.
And that sounds great at first, save a lot of money and also have a running solar system on the roof much earlier. The only question is, what do you need for it? How heavy is this? How long does it take? And above all: can three c’t-lers manage a complete solar roof installation together? We explain all that in this video. Stay tuned.
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So, up to 600 watts, i.e. with two solar panels, a system counts as a balcony power plant. We have already made two videos for this. For all larger systems, a specialist company must act as the installer. But the restriction only applies to the connection to the mains itself. Everything that has to do with bricks, rails, clamps and DC cables, you can in principle do it yourself. So, colleagues, can I simply fill my roof with solar panels myself?
Yes, of course you can basically install a photovoltaic system yourself. That’s not rocket science. You need modules, you need installation material, fastening material and you need inverters. The installation material consists of roof hooks. They come on the roof tiles, carried out under the roof tiles, with a small recess. Then they are screwed tight, an aluminum profile is placed on top of it and the modules and inverters are attached to it.
Okay, that doesn’t really sound that difficult.
But can I really do something wrong there? On the one hand it’s safety, if someone slips it could be dangerous. So working on the roof, I’ve always found something where I have a bit of a queasy feeling in my stomach. Otherwise, the bricks could break. We have to make cuts there. That might be a problem. But you have to look at that.
Okay, but solar panels generate direct current. Alternating current naturally flows in the power grid. All you need is an inverter. How did you solve that now?
We chose microinverters due to the shading of the garage where we installed the system. In other words, smaller inverters that are placed directly on the roof, on the profile on which the solar modules also fly. Unlike larger string systems, where all the equipment is usually in the basement. We have now used two pieces here for a total of twelve modules, mounted directly on the profile. That actually makes total sense here. We actually have a pretty difficult situation.
The garage that we’re talking about here is partially shaded. There is a barn on one side and a house on the other. In between, many modules are in the sun for large parts of the time, but there are always individual areas in the shade. And with a conventional system with a string, the system would immediately perform very, very poorly in the event of partial shading. And with these microinverters, we can surround that.
So the three of them’s system supplies more than four kilowatts, which is more than a normal fuse can withstand. A house is not only connected with one phase, but with three. And as far as I know, 32 amps are allowed to flow through each of them. But the cables in the house have to be thick enough so that they don’t get too hot, right? Do you have to pay attention to anything?
Yes, five times two and a half square are currently arriving in the garage. The entire garage is attached to it. There is also a 16 ampere socket attached. The whole thing is directly connected in a small, relatively small can. We will dismantle everything down to the cable that goes into the garage, we will then put in a small distribution box and put in various fuses, an LS plus FI fuse and two three times 16 ampere automatic machines.
And then the CE socket has its own fuse and the photovoltaic system has three 16-amp combination fuses.
So if you don’t really feel confident installing fuse boxes yourself, you should of course leave this part to the installation company. If you’re lucky, they’ll put the order in at short notice, as long as you don’t have to do any work on the roof yourself.
But what I still don’t quite understand is how long did it take to install the solar system in total?
It took us four days. On the first day we arrived here in the afternoon, set up the scaffolding on the garage and then started with the first of four pure roof hooks, which we then locked on the first evening. About the second day were the other roof hooks. That took a little longer than lunchtime. Then we put the rails on it and we already had one of the modules on the second day.
Yes, on the third day we covered the modules and as far as wired the second, put the second inverter and in the evening started to prepare the electrics in the attic of the garage, led the cable down to have everything ready for the fourth day Exactly, we didn’t need it all day, but we did the electrics in the garage for a few hours.
Test operation is complete. The system was briefly on the grid, is now off again and is waiting for approval from the grid operator. But we are confident so far. The system was running and has already delivered the first energy.
Well I’m pretty impressed I have to say. So I wouldn’t have been able to do that. But I don’t have the do-it-yourself gene like Pina, Jan and Andrjian either. But maybe some of you are just as brave and talented.
This video should give you a little courage to tackle the energy transition yourself. Yes, at least in the end the three have their plant
paid less than 5,000 euros in total in the garage and with the electricity saved and the 7 cents feed-in tariff for the excess kilowatt hours, they should have the money back easily in less than five years. Feel free to write in the comments if you would like to build such a solar system yourself.
I would be particularly interested if you intend to do it, but for some reason it doesn’t work. So too much administrative effort, not enough savings, landlords who are opposed and of course happy to subscribe. Bye!
c’t 3003 is c’t’s YouTube channel. The videos on c’t 3003 are independent content and independent of the articles in c’t magazin. Editor Jan-Keno Janssen and video producers Şahin Erengil and Pascal Schewe publish a video every week.
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