Cost to run my generator.

[bayview]

generators use very little fuel. IMO you will never save enough to pay for any other system based on fuel use. At full load maybe 0.5 GPH. Look at the makers spec for yours and remember they mostly run at less than full load.

 

[twistedtree]

If you want an easy was to ball-park a generator fuel burn, or the fuel to generate electricity from your engine alternator, you will consume approx 1gph for every 10kw of generated power. Just like your main engine, a generator's consumption is based (mostly) on actual generated power, not the size of the generator.