Customers with Pennsylvania utility Peco Energy Co. will now feel the zap of higher energy bills after the Philadelphia-based company implemented its 21.5 percent residential electricity rate increase on Monday.

According to the Philadelphia Inquirer, the increase will bring electricity rates up from 8.64 cents per kilowatt hour to 10.5 cents per kilowatt hour – a roughly $13.95 per cent increase for the typical homeowner who uses 750 kilowatt hours per month.

The large increase is spurring outcries from customers all over the city, and is expected to lead many customers to begin shopping for the best electricity rates offered by alternative energy suppliers.

Peco spokeswoman Cathy Engel Menendez said that because the company does not even earn any money through electricity supply, it may even encourage its customers to look around for the best electricity rates.

"The smart Peco customer would be shopping," Menendez said.

According to Pennsylvania Live, when state regulators implemented energy deregulation laws in 2011, it was considered a major win for the state's ratepayers, who are now allowed to switch to those suppliers with the best energy rates.