A plug-in solar system is optimized to cover self-consumption as soon as the sun shines. However, if electricity is generated when there is no self-consumption, then this remains unused if there is no possibility of storage. The yield can be optimized with little effort. We show how.
Preliminary consideration: Saving and controlling with BalkonPV
Compared to conventional "large" photovoltaic systems, balcony power plants are relatively small. If you want to optimize the yield, the question quickly arises as to whether you are actually saving something or whether you are not spending more money than you can actually save. Solar plugs are designed in such a way that they usually have an upper limit of 600 watts (old) or 800 watts (new), which means that the sun has to shine "fully" for almost an hour and a half in order for one kilowatt hour of electricity to be generated. Hardware doesn't live forever and so the investment should definitely pay off within a few years.
Julian's idea with smart plugs
In his VLOG, Julian presented a solution that works with fairly cheap smart plugs. In principle, it switches a portable memory (power station) with an intelligent socket and its timer function. This enables him to switch on the socket when no one is at home and therefore no electricity is being consumed.
Of course, you can adapt this solution as you like, which we tried out once. However, the power station used costs around €500, which at the current electricity price alone means that around 1000 kilowatt hours must also be made available for this investment to pay off. We took the smart plugs out of our store, which is why no costs were incurred for them.
The power station has a number of outputs, but the consumers must be connected directly to the station. At least in our household, the base load of electricity is caused by the refrigerator, DSL router and notebook. These devices are distributed throughout the house, which is why we made a compromise for the test here. As consumers, we only take the television. The TV consumes around 300 watts and with 2 hours of daily consumption we can use this to empty the memory.
A second intelligent socket with energy measurement is a gimmick. We use this to switch the smart plug in front of the power station a little more intelligently than is possible with a fixed time program. The home energy management system (HEMS) is used for this purpose, which regularly monitors generation and only activates the socket in front of the power station if there is more than the base load. Alternatively, this "measurement function" can of course also be used with the app/API of the inverter (e.g. Solarman).
Storage for balcony power plant "light"
A perhaps simpler variant is the use of a simple multiple plug - without a power station. Smartphones, drones, notebooks, tablets and all other devices are charged at the multiple plug. One thinks this is of no use, but a lot of small animals also make a mess here.
So before you buy a power station for a lot of money, you should think about using multiple smart plugs on devices that already have memory. Because one thing is clear: memory-to-memory charging is not really efficient.