The energy cost to freeze is similar to that of the multistage compression/expansion cycle. All the solid state cooling mathods are even less efficient, and you need a cascade. The only way this works is when the excess energy has to be sold at a loss due to baseload excess, and this would allow the power to be time shifted. This, as would other ways of load shifting, would work. Vertical storage via a gravity pond is far better as all stages have high efficiency. Battery storage also works well at high efficiency. https://www.csemag.com/articles/implementing-energy-storage-...