Unfortunately one of the biggest technical problems with renewables is that we still lack an efficient way to deal with energy storage. It's still relatively expensive, inefficient, and creating waste. Maybe in 20-30 years you will be able to live in the winter using the energy produced during the summer and stored in batteries that are cheap and 100% recyclable, but it's not a reality yet.

20-30 years is optimistic IMHO. We're still a huge technological breakthrough in batteries away for large-scale, high-capacity energy storage to be viable.

It might happen, but the technology still isn't there, yet we're going all in on renewables, especially in countries like Germany and Italy where nuclear is politically toxic.

“PV Diverters” supposedly remedy that problem. They use current transformers to detect when the home’s solar supply is outstripping its demand, and then switch on power consuming devices like electric water heating / air conditioning so the power isn’t wasted.