CHICAGO, March 29, 2013 /PRNewswire/ -- ComEd today filed with the Illinois Commerce Commission its annual update of electricity supply charges, the primary component of the "Price to Compare," which will take effect in June 2013. The average residential electricity supply charge for customers who buy energy from ComEd will drop from approximately $.07/kilowatt-hour to approximately $.05/kilowatt-hour, a reduction of almost 30 percent, as a result of lower energy prices. Customers that have switched to alternative suppliers for their electricity supply have likely been realizing lower costs already. As a result of Illinois' longstanding policy to bring electricity choice to consumers, ComEd customers can use the Price to Compare to evaluate offers from alternative retail electricity suppliers. About 75 percent of ComEd customers already have switched to an alternative supplier for their electricity supply. And choices are abundant: More than 40 alternative suppliers in ComEd's service territory are certified to sell electricity supply to residential customers, and more information is available at www.pluginillinois.org. "We know that customers are most concerned with their total bill each month," said Anne Pramaggiore, president and CEO, ComEd. "Whether customers get their electric supply from ComEd or from an alternate supplier, they are saving money as a result of lower energy prices." The Price to Compare is determined using expected electricity supply and transmission charges and makes up about two-thirds of the average residential customer bill. In May 2013, ComEd will file new transmission rates to take effect in June 2013. Transmission costs are expected to increase as a result of service-enhancing investments and are reflected in ComEd's Price to Compare. The other one-third of the bill is made up of delivery charges. Under the Smart Grid law, delivery charges are updated every year in January. In the next few weeks, ComEd will file its proposal for its new delivery charges to take effect Jan. 1, 2014. Under this proposal, delivery charges are expected to increase as a result of grid modernization and other service-enhancing investments, but the increase is largely offset by lower energy prices. "Even with these changes, for the next year ComEd customers' bills are expected to be the same or lower than they were a year earlier, because of lower power prices," said Pramaggiore. "And because energy prices are low, this is the ideal time to invest in grid modernization."