Smart Grid, Infrastructure Upgrades Credited with Historic Service Performance CHICAGO (March 27, 2014) – ComEd today announced that its power system reliability in 2013 was the best in company history with the fewest customer interruptions, benefitting hundreds of thousands of residents and businesses throughout northern Illinois. Improvements stem largely from the utility’s substantial investments in building a “smart grid,” implementing vast power infrastructure upgrades and delivering exceptional performance by the ComEd workforce – from frontline first responders to backroom engineers and technicians. Under the Energy Infrastructure and Modernization Act (EIMA) passed by the Illinois General Assembly, ComEd is investing $2.6 billion over 10 years to modernize the power system with digital technology and to replace, refurbish and upgrade electric equipment across a northern Illinois territory that spans from Lake Michigan to the Mississippi River. ComEd’s investments in a “smart grid” – an electricity delivery system that uses digital technology to provide customers with more information and control over energy consumption and costs — are also key to improving service reliability. These investments include expanded use of distribution automation devices or “smart switches” that automatically isolate and re-route power around problem areas. ComEd’s EIMA investments resulted in approximately 300,000 fewer customer interruptions in 2013, creating customer savings of approximately $48 million. “The long-term investments that we have been making are already producing very positive returns for our customers and will continue to do so,” said Terence R. Donnelly, executive vice president and chief operating officer, ComEd. “A fortified and more reliable power system improves the customer experience, saves money and helps attract, retain and expand businesses across the region.” “Investing in next-generation infrastructure, such as modern smart grid electricity, is a key component of Mayor Emanuel’s Plan for Economic Growth and Jobs, currently being implemented by World Business Chicago,” said Jeff Malehorn, president and CEO, World Business Chicago. “We’re pleased to see ComEd’s strong reliability performance for 2013, an attribute that helps us attract and retain 21st century jobs and business in the region.” ComEd’s reliability performance is among the best in the Midwest, ranking in the top decile for 2013 compared to 2012 performance of peer utilities and in the top quartile in four of the past five years. Power reliability and Illinois’ competitive electricity supply market are key reasons why businesses such as Airgas, DuPont Fabros Technology, and aeronautical and energy technology company Woodward have committed to building new facilities in ComEd’s northern Illinois service territory.

“Our reliability is proof of ComEd’s commitment to providing all of our residential and business customers with high-quality, dependable service to power their lives,” said Anne Pramaggiore, president and CEO of ComEd. “We also recognize that our investments in the smart grid will be a key contributing factor in helping establish this region as the Silicon Prairie and in creating competitive advantage, energy innovations and new jobs in northern Illinois.” Further to its economic impact, work under the smart grid expansion legislation supported an estimated 2,800 full-time equivalent jobs in 2013; fostered the development of innovative technology through the Energy Foundry, a private nonprofit venture fund established to support smart grid-related start-up businesses; drove business partnerships with a multitude of minority- and women-owned businesses; and helped tens of thousands of individuals facing financial hardship to pay their utility bills. ### Commonwealth Edison Company (ComEd) is a unit of Chicago-based Exelon Corporation (NYSE: EXC), the nation’s leading competitive energy provider, with approximately 6.6 million customers. ComEd provides service to approximately 3.8 million customers across northern Illinois, or 70 percent of the state’s population.