Question……
If you go to generator power, can you run your entire household, washer-dryer-stove-microwave-hvac-anything else, at the same time as you do when you’re home is on the power grid?
As far as the economics currently our natural gas costs slightly more than a dollar a therm. A gallon of gas contains 20% more energy than a therm but because natural gas burns more efficiently in our generator we use about the same number of therms as we do gallons of gas. We typically use 8 to 10 therms of natural gas or 8 to 10 gallons of gasoline per day. We pay about 10 cents per kwh so our electricity normally costs us $4 or $5 a day depending largely on the time of the year. When we are running the generator on natural gas our electricity comes to $8 to $10 a day. If we were running the generator on gasoline at the current $3.70 a gallon that would come to $30 to $37 a day.
The only “disadvantage” to natural gas in our case is that it limits our peak load just a bit so if that if we do put just a little too much load on one side of the circuit the generator starts bogging down and things start browning out. If we put too much load on one side of the generator when it is running on gasoline it will usually trip a breaker on the generator before it bogs down.
This is actually more convenient than running outside to reset the breaker on the generator. So for example... if my wife turns on her hair dryer and things start getting wonky she knows to plug it into a different outlet. And the house doesn't go black and yours truly does not have to run outside and reset the breaker on the generator.
We typically end up using the generator several times a year, usually for just a day or two and sometimes for just a few hours. It is a little noisy, but does not keep me awake. Some of our neighbors have systems with electric starters and automatic transfer switches that turn on automatically when the power goes out and back off when the power comes back on.
All of our neighbors have generators. Some of them have really large ones and had to pay a lot of $$$ to get a larger natural gas line to their house. Ours is small enough that the line we already had was perfectly adequate. They complain about how much fuel their generators use but if it wasn't for the noise, they wouldn't even know the power was out.
Of course the most fuel efficient generators are those with an inverter built in but they cost more and add a layer of complexity. But looking it up for my response to you I found that Harbor Freight now has a descent sized inverter generator for a reasonable price. I have to admit that this one is very tempting to me and might be helpful to people who want to run a heat pump or electric oven in addition to their normal load.
To convert ours I bought a regulator, some hose and fittings and printed a bolt on venturi of my own design on our 3D printer for the carburetor on our generator and use a motorcycle air filter on that. But I am not sure that it was worth the extra effort to save a few bucks.