Relationship of engine to payload question

In response to the comment by Tom:
I don't think the power source will really be a factor by itself. The issue is more related to having an equivilant source of power. In other words if I were running a .40 engine, what size electric would I need to produce the same thrust. When those two are equal the payload capacity would be the same. Hope this makes sense.

Electric or Nitro for RC Planes

I am really fascinated by the advent of electric power for RC aircraft. I flew for many years using the traditional nitro fuel for my models and have recently started flyin all electric models. I am not sure why so many enthusiasts have made the switch, but in my case it was a matter of convenience. My free time is very limited for flying and many times it was a last minute opportunity that arose. For example, I might suddenly have a canceled meeting and have a couple of hours open during which I could run to the field and get in a few flights. The problem arose that in that length of time my batteries were not charged and I would need to load my flight box, tool box, etc. No way would I get it all done and have time to fly. I decided to get a simple electric park flyer that I could throw in the truck. With a cigarette lighter adapter, I could easily charge up my batteries on the way to the field and enjoy more time actually in the air. As a result I am moving to an all electric fleet of planes. My first foray was with simple rudder/elevator control and am now ready to move up to larger planes with airelon control and larger engines. I would love to hear from others who went electric power and their reasons.