Construction costs are currently skyrocketing

Compressed air storage

All just hot air

That was good ;) Now you have somehow made me curious. What volumes and pressures for what amount of electricity are we talking about for private households?

and that even without a basic fee?!

That is not true, your subscription fee is your basic fee

I will make a detailed breakdown of all costs and a hypothetical comparison to a normal electricity tariff in the next few days.

Gladly, but as I said, not compared to just a normal electricity tariff, but compared to a normal electricity tariff for grid consumption + self-consumption - storage consumption + feed-in tariff for feed-in (which you have now assigned) + savings in storage costs.
Only then will you know if it was worth it.

Unfortunately, you don't hear anything about pumped storage power plants or compressed air storage for small consumers.

Personally, I find pumped storage very promising. You can basically build them anywhere, they require much less space than pumped storage, much less demanding technology than electrolysis, compressed air, or magnetically suspended kinetic storage. However, I also do not understand why this is not being promoted much more.
In Switzerland, there is an interesting provider pursuing a winch pumped storage concept.

However, I don't understand why this isn't being pushed forward much more.

Most engineers probably find it too archaic.
Lifting large stone blocks is so much 3000 BC.

Hehe Stonehenge is actually a hub storage. The corresponding winches are just missing.

As far as I'm concerned, the blocks should be stored magnetically to reduce friction loss. It would really be interesting if someone with physical expertise could explain this well – I mean why it hasn't been implemented on a large scale for a long time. Especially in the East, on the old combine sites, something like that could be well realized, in my opinion.

Yes, for example I use the Senec power cloud. What I feed in during the summer, I can draw from the grid again in winter. For last year, the kWh from the grid cost me about 20 cents. And I don’t have to pay an additional monthly basic fee.

If you forget the crazy acquisition costs, you can probably hold such an opinion.

Ultimately, a power cloud is a package electricity tariff that is pre-financed by exorbitant acquisition costs for a storage system. In addition, there is partial refinancing through the feed-in tariff that Senec receives. In my opinion, a complete scam package that carries a massive insolvency risk. Senec also has to buy the “cloud power” for the winter from the market... this could get interesting. It wouldn’t be the first “cloud” to go bankrupt. Then the prepayment is lost, leaving at least a storage system under criticism in the possession of the private customer.

That is not correct, your subscription fee is your basic fee

Yes, that is correct. But in the end, with the cloud, I only have one amount, namely the subscription fee. This includes a quota of electricity. With a normal electricity tariff, however, I have two items. Once the monthly basic fee and additionally the usage price. If I calculate the subscription fee down to the usage price, I can compare this with the usage price of the normal electricity tariff. But then I have no further costs, whereas with the normal electricity tariff I still have the basic fee in addition. I hope this is understandable :p