After actually testing the mod I stand corrected. I didn't realize that using H2 wouldn't allow an Oil Generator to produce its maximum output. I thought that it would simply consume much more fluids per second, like a boiler for instance.
So, for 10 Oil Generators 3, it's:
- 2,7 MW (Hydrogen)
- 20,4 MW (Hydrazine)
- 35 MW - max (Fuel Oil/Naphta/SynGas)
So yeah, since it works that way and not like boilers, you actually need a whole lot of Oil Generators to get anywhere with Hydrogen. Without even taking into account the production cost you mentioned. So, as you say, that's reasonable and once again, I stand corrected.
What's more, it's great to power oil boilers.
But at the same time, it's great to power oil boilers. And turbines. Which circumvents the inherent limitation of oil generators. (But that's anyone's business to decide if they want to exploit such flaw or not.)
About Hydrazine, I meant it the other way around actually. It's a good thing that it can be used everywhere. (Wouldn't make much sense otherwise, since it has a fuel value.) But…
It's a massive pain to produce, and even more so massively enough to power a factory.
Despite that, its fuel value is much, much lower (340 KJ vs 1,5 MJ) than something easily produced (Naphta/Fuel Oil and depending on whether or not you're using SynGas loop, SynGas). So the only saving grace would be the Hydrazine generator. But even then, I wouldn't imagine myself going out of my way, producing Hydrazine (with its resource/power/infrastructure cost) just to get a theoretical gain of 0,5 MW per generator.
Crude Oil
Crude Oil is less refined than Naphta and Fuel Oil, but has a 1,9 MJ fuel value which is actually higher. So perhaps some incentive to use Fuel Oil/Naphta might be needed. (Well, you can use both, coming from crude oil, to power generators so it might not be needed. Just wanted to bring that up in case you wanted to do something with it.)