in a portable gen set I can see gasoline and LP dual fuel but why natural gas.
By default, you get the ability to use natural gas when you add the demand regulator to the generator :C
Slightly off topic;
In my case I have a few natural gas quick-connects outside my home that are used for the BBQ grill and patio heaters. When I installed the conversion on my EU2000i I also bought some hose and appropriate connections so that I can simply "plug in" the generator to the gas line. In the 10 years I have lived here the power has never been out for more than just a minute or two, but if we ever had an extended power outage I have the option to use my generator as a power source almost indefinitely (that is, as long as the city had natural gas available) to keep the fridge & a couple of lights running. Given the fact that I live in an area of the world with
extremely reliable power, I could never justify the expense of installing a dedicated whole-house generator.
Cheers,
-Mark