With modern technology,

There MUST be a way to have off the grid Air Conditioning.

I know caves yearround temperatures between 52 and 62°F.

I live in a swamp city. Literally built on marsh, and surrounded by viney swamps. Caves are not present unless one made a cellar 30 ft under a forested hill, steel walls to keep the moisture out. Cold air is heavy so it would stay cool; dark, so only be used for sleeping.

Mechanical energy is 4x more efficient if it directly turns the AC, instead of being converted to and from electricity first. If there were a coastal wave energy collection and storage mechanism this would work, or residential wind farms with drive-shaft appliances.

Last I heard the future fuel was to be solar-generated hydrogen. I have not kept up with this research.

Anyone else have interest in this?

Look into geothermal HVAC systems.