Still, if it could be stored stably in the summer and converted to heat in the winter then possibly helpful.
I wonder how the efficiencies compare to producing hydrogen or other burnable gases.
That being said, there are some "hot rocks" companies who have been working with thermoptovoltaic cells. Which could still work, but the low hanging fruit is in the millions of direct uses for heat.
There are already sand batteries that store heat well and are used in northern climates: https://polarnightenergy.com/news/worlds-largest-sand-batter...
And even then, we already have the ability to create synthetic fuels from electricity, so any new development would need to be competitive with what we can already do.
I will once again point to Austin Vernon and Standard Thermal, which has an approach that could truly solve the problem. The first principles analysis of the issue shows the problem with "sand batteries" and the like.
https://www.orcasciences.com/articles/standard-thermal
"Given that heat capacities of solids are all generally similar at ~3kb per atom, we’d need to store heat in a solid that costs ~$10-30/ton or less and tolerates very high temps. But nothing built on a foundation or made in a factory is sold for less than $100/ton. There’s almost nothing that even gets shipped in the dollar per ton range."
The capex per unit of stored energy in undoubtedly far too high for that to be worthwhile. Seasonal energy storage requires extremely low cost storage media.