Interesting question.
Although some Professional Cleaners here in the States run their System using a generator, more do not. Instead, they run long extension electrical cords.
When I owned a Carpet Cleaning business in the seventies, we had 11 trucks running and never used a generator. Why? Because I felt that if we could lay out 100-150 feet of hoses, why couldn't we also do the same with cords?
In the end, this was never a problem (here in the States) and was very cost effective (more profitable) in regards to the bottom line--something the Bank & I really appreciated.
"Convience" is something we usually pay for, and this can sometimes be a very good thing; or it may not be to our advantage in added benefits; on the other hand, in terms of this on-going (overhead) cost. However, it is strickly a personal element.
Good Fortune to allBrits;
Ed Valentine
Cross-American Corp.