It looks like the biggest disadvantage to molten salt is the drop in generation efficiency. While the long term storage is fairly efficient, it loses a lot when they try to convert back to electricity. Hydro storage can lose efficiency due to evaporation, but they can still maintain 70-80% efficiency.
There's also geography that has to be taken into account for hydro, as you can't put it just anywhere.
>In a complete PHES cycle, water is pumped from a lower to an upper reservoir and at a later time returns to the lower reservoir, with a round-trip efficiency of about 80%. In other words, about 20% of the electricity is lost in a complete pumping/generation cycle.
>The topic is crucial because, at the present stage of power industry development, molten salt power plants are pioneering solutions promoted mainly in Spain and the US. Molten salt reservoirs have high storage efficiency (above 90%), but the efficiency of the energy transformation from heat to electricity is much lower at about 50%, which is a significant disadvantage.
Squirmin t1_irwr5is wrote
Reply to comment by pastor-raised in Geothermal May Beat Batteries for Energy Storage: Enhanced geothermal systems are well suited to store excess renewable power as heat. by filosoful
It looks like the biggest disadvantage to molten salt is the drop in generation efficiency. While the long term storage is fairly efficient, it loses a lot when they try to convert back to electricity. Hydro storage can lose efficiency due to evaporation, but they can still maintain 70-80% efficiency.
There's also geography that has to be taken into account for hydro, as you can't put it just anywhere.
>In a complete PHES cycle, water is pumped from a lower to an upper reservoir and at a later time returns to the lower reservoir, with a round-trip efficiency of about 80%. In other words, about 20% of the electricity is lost in a complete pumping/generation cycle.
https://iopscience.iop.org/article/10.1088/2516-1083/abeb5b#:~:text=In%20a%20complete%20PHES%20cycle,a%20complete%20pumping%2Fgeneration%20cycle.
>The topic is crucial because, at the present stage of power industry development, molten salt power plants are pioneering solutions promoted mainly in Spain and the US. Molten salt reservoirs have high storage efficiency (above 90%), but the efficiency of the energy transformation from heat to electricity is much lower at about 50%, which is a significant disadvantage.
https://www.hindawi.com/journals/ijp/2019/8796814/