This is as good of a place to start as any. After all it is a building block of sorts, the fusible link within a star and the plus sign in most combustible chemical equations.
[https://www.iea.org/reports/the-future-of-hydrogen]
In the early 1970’s, we saw the ‘oil embargos’ and huge increases in gas prices, 300% in a couple of years and that left fewer and fewer cars traveling for any distance. In the summer of 1974 I noticed the need for alternative fuel sources had struck home. My first inclination was to question why hydrogen had not been used, it is omnipresent and easily accessed. My immediate conclusion was the resulting exhaust would cool the atmosphere – this prior to any common knowledge of ‘global warming’ and I actually thought that cooling might be harmful – (HAH!) I am still a proponent of hydrogen power, and even tried to reach out to Bill Lear, who was an early pioneer; saying: “I am going to make a car that runs on water”, however, at the time, he was in failing health, but I did talk to one of his engineers, who said they had 14 different prototypes, much research has gone into it by now and several containment methods developed, from nickel hydrides and compressed gas combustion to fuel cell membrane transmission and all with good results.
I was still puzzled as to why its use was inhibited, that is until the economic impact on an already established corporate conglomerate revolving around fossil fuels and efforts to preserve the stability of that cash flow. The inability to regulate hydrogen was soon evident, it’s everywhere – go figure! [a small example of its impossibility to regulate, as an engineer – Clinton Power Facility – I researched why they didn’t use hydrolysis to store ‘ramp up’ energy that was currently going to waste, nearly 25% of all energy produced, I discovered it had been tried but didn’t produce sufficient revenue to abandon the tax credits which had been offered in lieu of legislation governing when and how they produce and sell their power] all now much outdated since the advent of brokering power.
So shade tree implementation has to run its course, patents are abundant and I even had my own multi-valve diesel style engine idea. The Japanese are so far out in front on this technology it would behoove the world to take note. powering homes, and indeed I have seen designs where (natural gas found hydrogen) fuel cells support entire communities, autos included and the batteries in the autos are a reserve power supply. Fuel Cell technology has come a long way.