Hydrogen has started to become more prominent since (most of) the world started talking about getting to net zero carbon emissions, rather than, say, 80% cuts by 2050. A net zero system needs to meet several needs which renewables and nuclear don’t meet well and which batteries don’t yet do much to help with.
The three biggest problems that come to mind are (a) meeting peak energy demand, (b) process heat for some industrial processes where there’s no current adjective to a burner, and (c) fuelling long distance vehicles like planes, ships and long distance truck and train routes away from big electricity infrastructure.
Hydrogen looks like a good candidate to be at least a part of the solution to all of these as it is currently expected to be the cheapest chemical fuel to produce at sufficient scale in a net zero manner. Multiple (proprietary, not all publicly available, but see [0]) predictions say that as scale grows hydrogen from electrolysis powered by dedicated renewable plant could reach prices comparable to those of natural gas in most parts of the world (not the US) today. The recurved advantage of hydrogen could disappear, but there’s no clear alternative today.
For (a) meeting demand peaks - a big problem in cold regions where space heat is a big part of energy demand and the occasional winter is very cold - hydrogen can be produced when the wind blows and the sun shines and then stored. This is easier in places with the right geography to store hydrogen directly (e.g. salt caverns), but hydrogen may still play a part elsewhere. Batteries are energy efficient, but very cost inefficient at long duration (in this case, months to years) energy storage.
For (b) fuelling industrial processes, hydrogen can usually be used as a direct alternative to oil or natural gas. Sometimes this would require new plant, sometimes not.
For (c) transport, batteries are more likely to develop to solve many challenges. Where they don’t (my guess: all but short distance aviation and shipping; very long distance trucking), hydrogen is the most likely chemical starting point to create net zero fuels - maybe hydrogen itself, maybe synthetic hydrocarbons, maybe ammonia.
Note that none of these is an immediate challenge anywhere today, so hydrogen is seldom a commercial solution. But they all will be to get a net zero future.
Now none of this means today’s hydrogen companies will be successful. In fact, based on past transformations, most will probably fail. And those that do succeed and grow, whilst technology driven companies, may well not be anything like either software developers or oil producers in terms of return. I’d guess a mix of smaller technology providers (maybe c.f. Arm if they’re very lucky) and something more like regulated utilities or merchant renewable developers: relatively low risk and thus return, capital intensive industries.
[0] https://about.bnef.com/blog/hydrogen-economy-offers-promisin...