Strong sunlight powers passive cooling device

https://discovery.kaust.edu.sa/en/article/1174/strong-sunlight-powers-passive-cooling-device

"powerful cooling effect that occurs when certain salts are dissolved in water. After each cooling cycle, the system uses solar energy to evaporate the water and regenerate the salt, ready for reuse... After comparing a range of salts, ammonium nitrate (NH4NO3) proved to be the standout performer... NH4NO3's solubility reached 208 grams per 100 grams of water... it is very cheap... The system... has no electrical components"

Related:

Passive cooling system could benefit off-grid locations

https://techxplore.com/news/2022-09-passive-cooling-benefit-off-grid.html

Self-cooling tent runs using just water and sunshine

https://techxplore.com/news/2023-01-self-cooling-tent-sunshine.html

MIT fusion of two existing passive cooling technologies augmented with thermal insulation enhances cooling efficiency

https://www.spikeswipe.com/post/a-leap-towards-sustainable-cooling-mit-s-trailblazing-passive-cooling-system