Table of Content
To cover the base load I have installed a small 300W balcony power plant for quite some time. I was able to gain some experience and optimize my own use of solar power. Now I am replacing my 300W balcony power plant with a new 800W balcony power plant. In addition to the new PV modules, I renew the substructure, the microinverter and, of course, the connection to the house grid.
During my rebuild, a few questions came up, which I would like to answer with this entry and my video:
👉 What components does a balcony power plant consist of?
👉 How to fix a balcony power station?
👉 Where do I point it to have the optimal yield?
👉 What do I have to pay attention to when connecting to the mains?
What is a balcony power plant and how does a balcony power plant work?
A balcony power plant is a photovoltaic system that converts the direct current of the photocells into 220V alternating current through an inverter. The electricity is fed into the domestic grid where it is directly consumed.
If the electricity yield is higher than the current consumption in the household, the surplus is fed into the public power grid free of charge. If the consumption in the household is higher than the current yield, only the additional consumption is drawn from the public power grid at a charge.
Thus, a balcony power plant serves primarily to cover the basic consumption of electricity in the household. However, the complete, self-sufficient supply of the household or even the charging of an electric car are not practically possible.
Unlike the large PV systems, a balcony power plant usually consists of only 1 or 2 PV modules, each with its own microinverter.
The installation and connection of a balcony power plant is quick and easy. The module is propped up and the Schuko plug is plugged into the socket – done!
Even the extension with another module is no problem. How this works, I have described here: Balcony power plant – build 2nd module and connect it with first module.
- - Solakons Solarkraftwerk bietet Ihnen per Software-Update einen nahtlosen bergang mit der Gesetzesnderung am 01.01.2024. Statt 600W, speisen Sie dann 800W ins Hausnetz ein. So starten Sie energiegeladen ins neue Jahr!
- - Durch die bifazialen Solarmodule knnen Sie bis zu 25% mehr Energie erzeugen, bei gleicher Wattzahl. Die Technologie ermglicht es, Sonnenlicht auf beiden Seiten der Module (Glas-Glas) zu nutzen.
- - Das Balkonkraftwerk 600W / 800W besteht nur aus hochwertigen Bauteilen. 2x Bifaziale 440W JA Solar JAM54D40 Solarmodule, 1x APSystems 600W/800W Wechselrichter, 2x 1,0m Verlngerungskabel, 1x 5m Kabel zur Steckdose & 1x Wechselrichterhalterung.
- - Mit der Telefon-App berwachen Sie Wechselrichter-Daten per WLAN-Funktion in Echtzeit. Sie sind direkt informiert ber tgliche & jhrliche Solarertrge & CO-Einsparungen! Dank einfacher Einrichtung und intuitiver Bedienung direkt startklar!
- - Die Bauteile der Stecker Solaranlage versprechen eine lineare Leistung bis zu 30 Jahre nach dem Kauf. Somit sind die Ertrge Ihres Balkonkraftwerks gesichert und bereit fr die Zukunft
Optimal orientation and use of a balcony power plant
Since photovoltaic modules produce electricity from sunlight, it naturally makes sense to orient the modules towards the sun. In the northern hemisphere, this should be towards the south.
The most sunlight is captured when facing south. Of course, the obstacles on site, such as trees or houses, must be taken into account. Any shade reduces the power yield, sometimes significantly.
Since the electricity from a balcony power plant is consumed directly, apart from the available storage options, a direct southern orientation is not the best solution for every household. When oriented to the south, the electricity yield is highest around noon – The chart of the electricity produced forms a Gaussian bell during the day.
However, depending on the situation in the household, the consumption is not congruent with the yield. In a household where the members are away from home during the day (work, school), the high consumptions are rather in the morning and evening hours. During the day, on the other hand, the power consumption should only consist of the basic consumption, which is mostly refrigerator, heating and standby devices.
There are now three optimization options for these households:
- The electricity-intensive consumers are used/programmed to run during midday hours. This should be no problem with the dishwasher or pool pump.
- The orientation of the modules is changed so that the potential yield is better distributed throughout the day. It makes sense to align one module to the southeast and one module to the southwest. In this way, consumption at peak times is better covered while the previously unused surplus electricity fed into the grid free of charge at midday is reduced.
- The PV modules are installed on a solar tracker. A solar tracker is a mount for PV modules which follows the sun both horizontally and vertically throughout the day. The PV modules are therefore always optimally aligned to the sun.
- ✅[Mehr Strom erzeugen] Zweiachsige Solartracker sorgen dafür, dass sich die montierten Paneele tagsüber dem Sonnenlicht aussetzen. Im Vergleich zu fest installierten Solarmodulen kann die PV-Stromerzeugung mit dem Tracker um mindestens 40 % gesteigert werden.
- ✅[270°-Drehung] Mit 2-Achsen-Antrieb und empfindlichem Sonnenscheinsensor kann sich der Solartracker um 270 ° drehen und die Paneele so gestalten, dass sie die Sonneneinstrahlung von der Nord-, Süd-, West- und Ostseite absorbieren.
- ✅[Beständig im Wind] Es gibt einen Luftgeschwindigkeitssensor für windige Tage, wenn er starken Wind erkennt (Daten können manuell eingestellt werden), setzt der Solartracker den Winkel zum Horizont automatisch zurück, um stabil zu bleiben. Durch das Bohren der Spreizschrauben in den Boden kann der Sockel auch bei Hurrikan oder Sturm problemlos fest stehen.
- ✅[Für verschiedene Panels] Entworfener Platz für 6 Stück 170W ECO-WORTHY Paneele. Für verschiedene Paneele berechnen Sie bitte nach den angegebenen Längenangaben. Die Querstangenlänge: 114,2 Zoll (2900 mm) Breite: 29,4 Zoll (1000 mm) Vertikale Stangenlänge (jede Seite): 45,6 Zoll (1160 mm) Breite: 30,3 Zoll (770 mm). Mit 1500N Treibgestänge.
- ✅[Für Hof/Hof/Feld] Benötigen Sie nur 114,2 Zoll * 114,2 Zoll Bodenfläche, 3,93 Fuß Höhe. Es kann problemlos auf Hof, Bauernhof, Feld und Flachdach montiert werden.
What are the components of a balcony power plant?
The kit for a balcony power plant is quite manageable. The main component is of course the PV module which produces the direct current with its photocells. The inverter, in balcony power plants much smaller micro inverters are regularly installed, converts the direct current into ~220V alternating current and synchronizes this with the applied current from the socket to ~50Hz.
For mounting and fastening, there is a wide variety of brackets, elevations or rail systems.
Suitable DC cables with matching MC4 connectors to connect the module to the inverter and a power cable (usually with a Betteri connector) to connect the inverter to the mains/power socket are also still required.
However, since most balcony power plants are sold in sets, you do not have to worry much about the right choice. In my experience, the sets are well equipped and the individual components are perfectly matched.
How to fix a balcony power plant?
As the name suggests, a balcony power plant is small enough to be installed on a balcony. But, of course, you can install your balcony power plant on the facade, on the roof of the house, flat garage roof, or simply on the ground. Even a mounting on the garden fence or on the carport are technically no problem – as long as the right bracket is used.
In my opinion, a simple, safe and proven support for a balcony power plant is an elevation with angled aluminum profiles. These elevations can be used for floor mounting and wall mounting. The horizontal angle can be easily adjusted between 0° and 90° with these mounts.
Another good option for mounting the PV modules is a rail system. These support systems are usually also used for the large photovoltaic systems on the roof.
With this support system, two mounting rails are first fastened on top of each other. This can happen via special roof hooks or also via the above-mentioned elevations. The modules are then placed crosswise or upright on these rails and fixed with special retaining clamps.
The assembly is simple and easy. With a cordless screwdriver and the appropriate bit, the assembly is done in no time.
In any case, the assembly should be stable and storm-proof!
My video for the project: Install and optimize 800W balcony power plant yourself
I documented the setup, the installation, the electrical connection and also the setup of the WLAN connection as well as the apps for monitoring the power output in a video. You can find more exciting videos on my YouTube channel or directly in the matching playlist.
Convert direct current to alternating current? What exactly does the inverter do?
The photovoltaic modules produce direct current through solar radiation. This can be charged directly into a suitable battery via a charge controller. Especially when setting up a photovoltaic island system or for power supply for the motor home or camper, this is a very good solution.
How this works exactly I have described in detail in my YouTube video PV island system build yourself | Solar power for garden & caravan | With power grid backup.
However, first and foremost, a balcony power plant serves as a support in the home for most users. The self-generated electricity should cover the basic consumption, the basic noise, and thus reduce the electricity costs in the long term.
However, 12V or 24V direct current is not sufficient for this purpose. The European power grid is rated at ~220V at ~50Hz.
Why am I writing about ~220Vand ~50Hzhere? Unfortunately, the power grid is not quite so “clean” and “stable”. 230V voltage or frequencies of 49.xx are common to measure. Since the balcony power plant synchronizes directly with its own power grid, however, this plays only a minor role in direct use. For better readability I will write 220V or 50Hz in the further course.
To get the direct current now to 220V alternating current, a voltage converter is needed. This work is done by the so-called inverter. While the normal inverter is relatively large and can “process” a large number of modules, the so-called microinverter is regularly used in the balcony power plant.
This microinverter transforms the direct current of the PV modules to 220V alternating current. At the same time it synchronizes the frequency of the “new” alternating current with the frequency from the house current. The process of synchronization may take a few minutes. Subsequently, however, the newly generated electricity is fed into the domestic grid at the appropriate voltage and frequency.
Modern microinverters often also have a connection for a 2nd PV module, an internal data logger and an integrated WLAN module. The inverter can therefore be integrated into almost any smart home.
But the microinverters have a second function – fast shutdown.
The power contacts in an outlet or on an extension cord are well protected against accidental contact. The probability of getting an electric shock when inserting a power plug into an earthed socket is therefore very low.
It is different with the connection plug for the balcony power plant. The cable ends with the Schuko plug and the metal contacts exposed there. When the sun shines on the PV modules and the power plant produces electricity, these contacts are energized. Electrocution would be quite likely.
However, to prevent this from happening, the microinverter immediately switches off the power as soon as the plug is removed from the socket and there is no longer any grid connection. This happens very quickly and thus protects against dangerous electric shocks at the open metal contacts.
Even if the technology is established and basically works, the Deye case has shown that one should not blindly rely on these safeguards.
Deye had subsequently eliminated the relay that performs the shutdown on some already-approved inverter models. Automatic shutdown when the plug was pulled out therefore no longer took place.
Verlngerungskabel beidseitig Solarstecker Solarkabel rot/schwarz 4mm inkl. Stecker, Made in Germany (2 x 5m)*Price: € 16.95instead of: € 17.95
Hi-Spec 99-teiliger Bohrer Set mit Titan HSS-Stahl 14 Größen 1mm-10mm Holz, Metall, Kunststoff in einem Aufbewahrungskoffer*Price: € 24.99instead of: € 28.99
Price: € 9.39instead of: € 19.49
Betteri BC01 Netzanschluss Buchse Netzstecker AC 3-polig IP67 & Betteri BC01 Netzanschluss Stecker male Netzstecker AC 3-polig IP67*Price: € 11.32instead of: € 12.38
Price: € 250.17instead of: € 377.00
Balcony power plant – Connecting inverters correctly – Betteri, Wieland & Co
The balcony power plant has been constructed and mounted in the correct location with the appropriate bracket. So how does the electricity get into the domestic grid?
First, the PV module must be connected to the inverter. Therefore, there is a plus cable and a minus cable with a matching MC4 connector on each of the modules. These plugs fit directly into the connectors from the inverter. The MC4 connector also protects the connections from dust and splash water. Rain and even snow are therefore no problem.
Since the cables on the modules are only very short, the inverter must always be mounted in the immediate vicinity of the modules. As long as you use a separate inverter for each PV module, this is not a problem. However, modern balcony power plants usually consist of two PV modules that share one inverter with two connections. The length of the connection cables then often no longer allows any play for the alignment of the modules. It therefore makes sense to extend the DC cables. This is done using suitable photovoltaic extension cables with matching MC4 connectors.
But beware: the length of the cables for safe and effective use is limited.
The required cable cross-section in mm² is calculated as follows for direct current:
A = (2 x length x current) / (conductivity of the cable x voltage drop x voltage)
Voltage (see nameplate module)
Connected load (in watts) or amperage (in amps – see module nameplate)
Voltage drop (usually around 1 to 3 percent – 1.5% is a good average)
If the inverter is not to be installed several meters away from the PV module, the usual 4mm² connection cables can be used.
There are currently three options for connecting the inverter to the home power grid – note the disclaimer at the end of the article). Available are the connection via Schuko plug, via Wieland plug and the direct wiring.
In contrast to direct wiring, where the 3-wire power cable from the inverter is permanently connected to the phase, neutral and protective conductor from the house mains, the connection of the Schuko plug and Wieland plug is made with one plug. If required, this could simply be pulled out of the contact box in both cases.
The difference between the Schuko plug and the Wieland plug is the shielding of the live contacts. As I wrote above, the contact pins of the Schuko plug are open. If the emergency shutdown of the inverter does not work, an electric shock is quite possible.
The Wieland plug shields the contacts both in the junction box and on the plug itself. Accidental contact with the live contacts is therefore very unlikely. However, in order to use this system, the Wieland box must first be professionally installed and connected to the home power grid. The Schuko plug, on the other hand, can be plugged into any Schuko socket.
The right socket for my balcony power plant
If the balcony power plant is now connected to the domestic power grid, the connection type, i.e. Schuko, Wieland or direct wiring, is only one aspect. A second aspect is that the power cable in the house is also up to the expected power.
As a layman, I would like to express myself as follows:
A normal 1.5 mm² power cable, as it was and is very often installed in households, is designed for 220V continuous operation of 3600W. Therefore, the safety instructions of the junction boxes always state that the total power of 3600W must not be exceeded.
The cable itself probably still offers reserves of up to 4200W, but many contacts and connectors are not designed for this permanent current flow. The power line would heat up enormously due to the load and a cable fire could then occur at some weak point.
The power on the power line, i.e. the current that flows, is the sum of all the consumers connected to this power line plus the power on the power line. the feed-in of the balcony power plant.
An example –
Watt = Volt x Ampere (W = V x A)
The power line, 1.5 mm² is fused with 16A (~3600W). A fan heater is already connected to this power line via a socket in the living room. The fan heater has a power of 3200W. In continuous operation, the power cable would already heat up.
The balcony power plant is now also connected to this power line via an outdoor socket and supplies just under 100W in the morning. The line is now loaded with 3300W. The cable would get even warmer, but without causing damage or a cable fire.
If the power plant now supplies 600W at noon, the power line is already loaded with 3800W. The cable would become very warm and existing contacts and cable clamps may catch fire. However, the circuit breaker would not trip because only 3200W is still drawn through it.
To prevent a cable fire, connect the balcony power station to a suitable power line. Ideally, a separate 2.5 mm² power line from the power plant to the house distribution/fuse can be used for this purpose. If this power cable is not available or cannot be re-laid, the consumers on the corresponding circuit must be used in such a way that a permanent overload of the power cable can be excluded.
Technically, this could also be solved by replacing the circuit breaker. The 16A automatic control unit secures the power supply of all consumers up to 3600W. However, the output of the balcony power plant would be fed in additionally.
However, if the fused power, including the power plant, is below the 3600W, this would significantly increase safety. Changing from a 16A circuit breaker to a 13A circuit breaker, would activate the protection from a power consumption of about 3000W. Plus the max. Power of the power plant, the power on the power cable would be limited to 3600W. In this case, however, the circuit breaker would always trip when the fan heater is in continuous use.
To which phase must the balcony power plant be connected?
Incidentally, it does not matter to which phase of the power grid the new power plant is connected. As I wrote at the beginning, the generated electricity is consumed directly. Technically, it may well be that the generated electricity is fed into the public grid and the current electricity consumption is drawn from the public grid on another phase.
However, since the electricity meters operate on a net basis, only the difference between feed-in and purchase is counted.
The household consumption on L1 is 250W and the power plant produces 350W on L2 at the same time. The generated current of 350W is fed into the public grid on L2 while at the same time 250W is drawn on L1. The electricity meter calculates a net consumption of 0W (mathematically, the electricity meter should turn backwards due to the surplus of 100W – which is prohibited in Germany).
Total consumption: 250W Chargeable purchase: 0W Savings: 250W
The household consumption on L1 is 500W and the power plant produces 350W on L2 at the same time. The generated current of 350W is fed into the public grid on L2 while at the same time 500W is drawn on L1. The electricity meter calculates a net consumption of 150W, which would then also have to be paid accordingly.
Total consumption: 500W Chargeable purchase: 150W Savings: 350W
The household consumption on L1 is 250W, on L2 200W and the power plant produces 350W on L2 at the same time. The generated electricity is already used within L2 and the surplus of 150W on L2 is fed into the public grid. At the same time 250W are referred to L1. The electricity meter calculates a net consumption of 100W, which would then also have to be paid accordingly.
Total consumption: 450W Chargeable purchase: 100W Savings: 350W
So, provided that the household electricity consumption is equal to (or higher than) the electricity yield, it is worth considering the installation of a balcony power plant.
Reporting obligation and market master register
Once the balcony power plant is in place and the sun is shining, the power generation can finally start – unless you live in Germany! Here it needs then nevertheless still some applications, notifications and other bureaucracy.
As I write these lines, the following applies (without guarantee):
- The balcony power plant may not exceed the max. Output power of 600W per electricity meter/household connection must not be exceeded. The power of the modules can be significantly higher, the decisive factor is what power the inverter feeds into the grid. As of 01.01.2024, this limit is to be raised to 800W, as is already common in many other EU countries.
- The balcony power plant must be registered with the local energy supplier. For this purpose, the EVU (energy supply companies) usually offer their own forms. However, approval by the RU is not required. So the municipal utilities are not allowed to prohibit the operation.
- The balcony power plant must be registered in the market master register.
- Other frameworks from BMI.
How to connect the microinverter to your private WLAN and how to monitor the power generation with the app you can read here: Balcony Power Plant – Set Up Solarman App | Deye Cloud App
Please note that I write in this post my own experiences and thoughts. When rebuilding, the following applies: Inform yourself about the specifications, guidelines and laws to be observed. In addition, work on electrical systems should always be carried out by competent persons!
Feel free to write constructive feedback in the comments section.