1. If you believe in learning curves, you believe that green hydrogen will be cheaper than fossil fuels (per BTU or per kWh) in the foreseeable future. That doesn't mean we should use it for everything -- it will mostly be cheaper to use wind and solar power directly, or through batteries -- but it does mean we're likely to use a lot of it, especially given the following additional points.
2. Hydrogen is one of very few solutions to important classes of decarbonization problems. Basically, hydrogen lets us use electricity to replace fossil fuels in places where direct electrification is difficult. To summarize, this is mostly about contexts where we use fossil fuels as a feedstock (a physical ingredient), eg fertilizers or plastics or steel, or as a high-volume fuel for transportation (eg container ships or transcontinental flights) or energy storage.
3. Speaking of energy storage. Lots of people say hydrogen is a dumb way to store energy; we should use batteries instead. I agree we should deploy more KW of batteries than KW of fuel cells or hydrogen-fired turbines, but I also believe hydrogen is the cheapest solution to seasonal power storage. (NREL also believes this.) Did you know that America uses ~2x as much energy in February vs in October? When we replace gas and coal with wind and solar (or nuclear, whatever) are we going to build enough for February or enough for October? The answer is to build enough for the average load, and to use hydrogen to store the power in vast underground salt caverns. This is much cheaper than the obvious alternatives (overbuild wind+solar+batteries). Basically, a lowest-cost fossil-free system would have more KW of battery energy storage and more KWh of hydrogen energy storage.
4. Hydrogen is transmission, and especially in the US, that means it's a solution to the #1 bottleneck that is preventing the construction of new wind and solar plants. Wind and solar energy are cheap, but there is a literal corrupt monopoly system (power utilities) which prevent it from competing fairly with fossil fuels, or from being transported from resource-rich areas to demand centers. Lots of people don't know this, but "interconnection" (the rules which allow utilities to impose delays, fees, and clandestine sabotage upon new wind and solar projects) is the #1 problem facing renewable energy projects in the US. The "interconnection queue" is like a line that wind and solar projects must wait in for years before they learn if their request will be approved, denied, charged outrageous fees, or simply deferred. In some places (MISO) regulators have approved a "pause" in the interconnection queue, meaning that nobody is allowed to get in line for the next several years. Hydrogen can help clear this up, and isn't subject to the same monopolies in the same way; one hydrogen pipeline can move as much renewable energy as 5-10 giant transmission lines, using one 50' right-of-way and no visible infrastructure (vs transmission towers, 500'-2000' of right-of-way and 100'+ tall towers).
If you're a transmission nerd and you don't already love hydrogen, be aware that we are literally planning a US supergrid today, and it will be operational by 2030. It's just pipes instead of wires; it's arguably jankier (and arguably not https://www.sciencedirect.com/science/article/pii/S2211467X2...) but definitely capable of solving the problems that make us talk about supergrids.
5. Final reason hydrogen is cool: it is not innovative. Innovation in the energy sector is very hard! If nuclear SMRs follow the optimal path, it will be 2035 before they are deployed at GW scale, and 2060 before they are deployed at TW scale. That's because innovation is about things that haven't been done before, and that means risk, which is toxic poison for infrastructure finance. Hydrogen can ramp up that same scale way way faster (electrolyzers are ramping from 1MW to 1GW in annual US deployment between 2013-2023) because it's all dumb 1950s tech that has been extensively studied.
In summary: I'm on a team called "build wind and solar fast to replace fossil fuels", and I found hydrogen in the course of studying how our team wins. It's a really cool tool! Thanks for reading my rant.