If the city of Chicago decides to leave Commonwealth Edison for a different electricity provider, residents who decide to stay with the utility may end up paying higher electricity rates than those who switch, the Chicago Tribune reports.

According to the news source, 250 communities throughout Illinois are already buying their electricity from retail energy providers thanks to energy deregulation laws that have been implemented in Illinois. Those who switch save, on average, 15 to 40 percent compared with ComEd's rates.

Energy distribution experts say that if Chicago parts ways with ComEd, its remaining customers would be forced to pay electricity rates that are twice as expensive as current prices for the same amount of electricity. The math is simple, they say. The left behind customers would be forced to carry the added weight of the expensive electricity contracts the utility has attracted since 2007.

According to Spark Energy, energy deregulation has been a successful move in Illinois, where energy customers now have the option to choose which electricity provider they will receive their electricity from. Many options are available, and retail energy providers typically offer major incentives to entice consumers to switch providers.