Sulphurreal's solar sulphur cycle makes unlimited thermal energy storage

https://www.solarpaces.org/why-solar-sulphur-cycle-ideal-seasonal-thermal-energy-storage/

"Sulphur’s energy density order magnitude higher and sand particles remain stable without degrading at much higher temperatures than molten salt... sulphur is cheap... burning using concentrated solar (no C02 emmissions) enables temperatures 1000° - 1500°C, centrifugal force creates dense particle film absorbing heat... enclosed endless cycles: sulohur --> sulphuric acid (valuable in itself)--> sulphur dioxide --> sulphur... power density >5 MW/m³ at ambient pressure (> 75 MW/m³ at 15 bar pressure)... seasonal storage"

Related: Study finds volcanic ash could store excess solar energy
https://interestingengineering.com/innovation/volcanic-ash-storage-solar-energy