Burning fresh brown's gas in the engine is good because the fuel has less energy than the gas. Meaning the accumulator energy make the hydrogen and oxygen provides more power than was applied to produce it, the gas is mainly free.
Never point it at someone or get too close about the industrial diesel generator you're cleaning (you may hit by flying debris or water bouncing back off the surface). Ideally, wear safety glasses and close toed sneaker. If using a noisy gas or diesel powered model, discover wear proper hearing defense.
Get the fuel efficient branded appliances. Sure they will cost a bit more than a plain model however the efficiency and reliability of the branded models will certainly save you money in the longer term. The above Honda model example above can consider 8 hours without refueling!
Living Off-Grid can include of a way to economize but that would require free energy.