There are proposals to store renewable hydrogen underground in geological formations similar to those used for storing natural gas. Has this been done successfully and are there technical challenges to storing hydrogen in this way that differ from those encountered when storing natural gas?

Geologic hydrogen storage is not new technology. There are several locations around the world that store hydrogen underground, predominantly in salt caverns, although there are other geologies believed to be suitable for large-scale storage. _________ See: Kobos,...