When we are on site without electric, we sometimes put the genny on to watch TV, charge up things and run a bit of air con if very hot.......... But, did you know that they consume about a gallon of fuel per hour? This 'fact' was taken from an American site, so although an american gallon is slightly smaller, it does give an indication of fuel consumption. I also found this - which seems incredible, but some people must do it - 'Never run your generator when you are sleeping! Even with a carbon monoxide detector. Carbon monoxide is deadly and it's not worth the risk. Generators are designed to run for long periods of time if they have the correct percentage of load on them. You should consult the generator owner's manual for load ratings.'