If it’s not overly humid, evaporative air conditioners are a cheap to run way to keep cool. The personal units (Convair Classic etc) are typically about 50 to 80 watts, so a single solar panel, battery and inverter should guarantee safe, grid free cooling for one or two people.
These might be worth trying, I don’t know.
https://www.womenshealthmag.com/life/g44762001/best-wearable-neck-air-conditioners/