On this planet there are 1.6 billion of people that do not have access to electricity refrigeration or stored fuels.
The Solution:
An inexpensive refrigeration that doesn’t use electricity, propane or gas. The intermittent absorption refrigerator.
This solution, invented in 1928, could be used for the storage of vaccines as well. It’s low pressure and non-toxic. it could impact the file of a huge number of people. I really hope this goes into production.