I often daydream about electrolysing water to generate oxygen and hydrogen and store them to use for heating and like welding torches and stuff.

To make electric energy I would have to make a small steam plant to run a turbine.

>To make electric energy I would have to make a small steam plant to run a turbine.

Or a hydrogen fuel cell: https://en.wikipedia.org/wiki/Fuel_cell

The round-trip efficiency is of course abysmal compared to batteries, but if the input energy is "free", the increased density could pay off.