Consultation for photovoltaic system

So if we now have a sunny day in April or May, the photovoltaic system first charges up. The storage should of course be charged first. It is full in 2 hours. Photovoltaic yield is from 08:00 to 16:00. So on a sunny day, ideally 50 kWh. (7kW x 8 hours) Everything has to happen during this time. Laundry and dishwashing, cooking, vacuuming, etc. The next day is rainy. Here the storage then covers the base load. We don’t need laundry and dishwasher every day. According to my calculations, the 7.2 kWP photovoltaic system should be optimal for the 10 kW storage. If it turns out that it is not enough, then a few more modules just have to be put on the roof.

According to my calculations, the 7.2 kWP photovoltaic system should be optimal for the 10 kW storage. If it turns out that it is not enough, then a few more modules will just have to be added to the roof.

There are two factors that must be considered if a storage system is to pay off: It must be fully charged as often as possible throughout the year. For this, a ratio of module power to storage of about 3:1 is needed. It must be emptied as often as possible throughout the year. For this, a small storage or very high, unavoidable electricity consumption at night is needed. If this leads to over 200 full cycles and the system was not purchased too expensively, the storage will probably break even. Maybe better if electricity prices explode, maybe worse if the storage explodes. ;-) The risk remains, of course. What worsens storage profitability are a heat pump and e-cars (because they are naturally prioritized to avoid storage losses). One should be aware that within the lifespan of a photovoltaic system, no one will get around these two things. But since you are building it yourself, if I remember correctly, you can easily retrofit. Maybe it makes sense to keep this in mind when you run empty conduits, buy inverters, or place modules on the roof, so you don’t limit yourself.

very little fits with your numbers. The storage is too large and the photovoltaics too small to be particularly economical or environmentally friendly. As already said several times. In summer, you don’t manage to drain the 10kWh at night and in winter not fill it up. But I find it very commendable that you want to align your lifestyle habits with the sun. However, that has nothing to do with a storage system. And once again, in general, why is it so difficult to distinguish between kW and kWh? Most people manage m vs. km and m/s vs. km/h quite well. This isn’t about being a know-it-all, it is often simply very confusing what is actually meant.

oder umweltschonend zu sein.

This is by no means a home storage system. It is simply another electricity consumer (and not a small one!) that has to be produced with great energy expenditure. And it prevents all neighbors from obtaining good green electricity directly from the neighborhood. Almost loss-free.

There are usable calculation models for the price that a kWh from the storage costs over its (realistic!) lifetime. Based on that, one decides whether it is worthwhile. Environmental aspects of the hardware aside. Currently, it is likely moving in that direction, but still below economic profitability.

During this time, everything has to happen. Laundry and dishwashing, cooking, vacuuming, etc.

I’m telling you, with your behavior you actually wouldn’t need a storage. Invest the saved money in additional space, then enough will come off the roof even on rainy days. And as someone once wrote in the Photovoltaik Kaufhaus: Grid consumption is not an illness ;)