Come run it in Finland during the summer months, we have too much solar and wind generation then and electricity is often free or even goes negative every once in a while.

It's useful if you can rig it to solar or wind, but that's about it. Hydrocarbon fuel is convenient because it's compact and energy dense compared to must other fuel sources. If the world ran on nuclear and renewable energy entirely, it would be extremely useful to create a circular carbon economy without digging up new fossil fuels. In our shitty reality though, it's only marginally useful.