I have a 3KW Honda generator (the eu300is, really good.) It sits in my garage under its cover with a trickle charger feeding it current. On the wall I have a rolled-up heavy gauge electric cable long enough to reach it when it is rolled outside, which feeds the current back to a six-breaker transfer switch installed next to my 200A house panel.

I also keep (3) 5gl red metal jerricans full of gas in the garage, spiked with Stabil. Yes, I know that's a terrible place to store the gas. I run the generator for a few minutes every couple of months.

We recently had a stick-built 12'x12'x7' shed constructed in the corner of our back yard. Two windows, concrete pad floor and both 110V and 220V service (in case I want to add a compressor later.) The shed is not insulated, but it does have a shingled slant roof with a ridge vent. We're using it for storage primarily, camping stuff, lawnmower, power tools, etc.

Naturally I'm thinking about moving the generator to the shed and getting it out of the garage.

Questions: 1. If I open the windows, what's the danger of CO buildup running the generator in the shed during power outages, if no-one is in there while it's running? (Except to run it and refuel/turn it on and off). I like the idea of having it in a protected space during a storm. Right now, it would sit in front of my garage, in the elements, when needed. 2. Is it better to store the fuel in the shed? If not there, or in the garage, then where?