Honestly, I think all the talk about seasonal storage is a misguided attempt to "not waste" energy when an economic system would likely "overbuild and curtail" as a seasonal solution. @cody_a_hill nails that point here (in an interesting discussion on storage economics). https://twitter.com/cody_a_hill/status/1110681523684954112 …
Seasonal storage of thermal energy is a big part of why geothermal heat pumps are Beneficial Electrification.