All of which is not to say solar won't be more important than gas, coal or nuclear in central europe going forward. Just that wind will take the front seat.
In case you aren't aware latitudes reduce solar energy collected per square meter of land. This can be motivated by tracking solar panels. But what can't be mitigated are shorter days in winter that get more extreme the further your are from the equator. In Helsinki right now the sun rises at 9:30 and sets just after 3pm.
I don't doubt your critical reasoning ability, but I do doubt the wisdom of treating the challenge of provisioning and operating massive seasonal storage on the order of terawatts as a solved problem because of a few district heating projects.
Yes. Huge problem. Very nice and good faith objection to something that can be done incredibly simply with a few dollars per kWh. What if some hot water or sand leaks out and contaminates an entire country?