Evaluation of Photovoltaic Offer and Components

Whether a private storage helps the grid is questionable. They don’t even relieve the correct phase. Then there is the fact that most regulate very poorly. So always charging in the morning when the grid doesn’t have enough yet and only giving back at night when the grid has enough. And in winter, when the actual demand is, they stand empty in the corner. To help the grid, they would have to use information from the grid and not just try to save the owner a few cents...

Then there is also the fact that most regulate very poorly. So always in the morning, when the grid doesn't yet have enough, it charges

Is that so? Are there not already systems that can be set so that storage only occurs above a certain yield or that a maximum of 20% of the yield is stored?

Are they really just standing completely idle in winter? I mean, apart from a few days, we really had photovoltaic yields all year round in our old house. We only had a 4.55 kWp system then. Now we get over 12 kWp. The highest load we ever saw in the old house was 6 kWh, my husband said. Usually, our house consumption is well below that. I would expect to at least get partial cycles even in winter. Maybe you can’t get it fully anymore, but it should bring some benefit even then?

The winter days are probably the reason why people rather calculate with 170-200 cycles per year, not with 365. =)

I still have my old Sunny reports. The numbers should roughly be tripled, since we are getting a system about 3 times as large. You can't fully charge the storage with that, but a few kWh will probably go in on most days.

Of course, the storage is not left empty all winter long. I reached a total of 260 cycles with my storage in 2021. In 2022, it was 230 cycles (due to the weeks-long remote shutdown of the storage by Senec). Here are some values of how much the storage charged during the winter months: November 2022: 223kWh December 2022: 91kWh January 2023: 103kWh February 2023: 190kWh March 2023: 200kWh

The larger the photovoltaic system, the more likely it is that something naturally ends up in the storage even in winter, yes. But you have to convert these small daily yields into "production hours" to see whether the household doesn't consume all the yield anyway. Especially when working from home. On the other hand, there is also a maintenance charge from the grid. 260 cycles is quite a lot. You would need to learn more about the system size and your own usage behavior. Individual values can be very misleading.