Try the diesel generator. It is similar efficiency to the burner generator but provides far more power in the same space, and still does not require water input.
I don't mean to speak for Klonan but I get the impression he isn't interested in making tiered upgrades. If you want more power, the answer is to build more generators. If you want higher efficiency, use a later tech, or set up trains to haul in the coal at a higher rate. You can also use efficiency modules in most buildings to make them use less power. The options are there.
