A 3000 watt generator should not have enough max. VA to start the electric motor load. If trying to take the entire load of the generator from a single receptacle, be sure ampere rating of receptacle is not being exceeded. Make sure that extension cords used with generators are properly sized for load and cord length. It is important to use extension cords of adequate current carrying capacity when utilizing a generator to operate portable electric tools.
Undersized cords result in excessive voltage drops and additional power plant loading.
This also causes excessive heating of the portable tool because voltage drop reduces tool capacity. In any power generation system, you have several options. The energy used is still the same, regardless of how it is generated. Personally, I think the first systems must be hybrids, using a combination of several technologies. The basic principle is to convert water to hydrogen and oxygen, mix it with air and explode these intermixed gases to drive an off the shelf engine.