There are better alternatives than just lithium batteries - for example liquid batteries by company with a weird name - RedFlow: https://www.youtube.com/watch?v=4OHstY_kKUY.
Edit: I also wonder how balanced heat and cold is in such system? One side effect could be cooling solar cells to improve efficiency of them. I had an idea few months back - why solar cells don't come with antifreeze that could be used to warm up your hot water in house?
I thought they did. Well, at least I know of installations that use solar power to heat water. Maybe there are combined panels that do both heat and electricity?
Fun fact, that's actually what we had in my last house. My dad wanted to heat the pool like that, so he Googled around, found a guy with a patent, and the guy helped him figure out how to build it for the house.
Edit: I also wonder how balanced heat and cold is in such system? One side effect could be cooling solar cells to improve efficiency of them. I had an idea few months back - why solar cells don't come with antifreeze that could be used to warm up your hot water in house?