I know that storage systems are often criticized, but we have had ours in operation for 3 weeks now and I have to say, it pays off for us very well.
At the beginning, I also did all the math where you calculate the purchase price, compare it to the warranty, and then calculate how many cycles per year you would need to break even within the warranty period. The cycles I calculated were already a rather pessimistic assumption for us – so I considered the probability of not achieving that to be low.
Currently, it is late summer, the air conditioning is running, the car is charging, and there is no question of "not being able to empty the storage." We manage to empty it every single night, and also fill it up every day.
We are curious to see how the winter will be – especially because the demand for the air-to-water heat pump will also increase then. Currently, it only heats water. The air conditioning is therefore off. Whether the higher load plus lower yield will mean that we can no longer fully charge the storage remains to be seen. At the moment it is already full at 12 noon, so there is still plenty of room.
Even if there are fewer cycles in winter – I am optimistic for 3/4 of the year.
