I love stories of successful implementation of “appropriate technology“. Here’s a refrigeration device that uses no electricity being set up in northern Nigeria. It is built by placing a clay pot inside a slightly larger pot and filling the gap with sand. By wetting the sand, the evaporative properties create a significant cooling effect (much like the old water bags on the front of jeeps kept water cool). Food that used to last only days, now lasts weeks.
A side issue is that young girls that used to be saddled with the daily duties of retrieving fresh produce for the family, now are increasingly able to attend school.