Pat Boland, the utility's credit policy manager, said Xcel doesn't like to cut off service but has to keep unpaid bills from getting out of hand during the recession.
The company says some customers were cut off for only a few days until they paid their bills.
Minneapolis-based Xcel is Colorado's largest electric utility.
It supplies electricity, gas or both to about 1.3 million customers in the state.
Since 2006, Xcel has averaged $25 million a year in unpaid bills, and Boland says the write-offs end up being paid by other customers.