US-based energy provider Exelon’s unit Commonwealth Edison Company (ComEd) has investigated and upgraded more than 6,200 manholes, underground structures containing large electrical cables, to increase the reliability of power supply in Illinois.

ComEd has examined over 10,000 manholes since 2012 as part of the grid modernization program under the Smart Grid law to improve the electric system’s reliability.

Manholes power skyscrapers and densely populated residential and commercial neighborhoods across the system.

Commonwealth Edison Company executive vice president and chief operating officer Terence Donnelly said the upgrade work results in shorter outages for families and businesses and improve the safety of workers.

"It’s part of our vision to improve the customer experience and be the new model utility," Donnelly added.

As part of the grid modernization effort, ComEd is also increasing its manhole inspection program, capturing more data on the condition of manholes and accelerating work to refurbish them and improve electric reliability and safety.

In order to maximize data gathering efficiency and minimize data entry error, ComEd’s engineers have developed a new online assessment tool for capturing manhole data, including current condition and any unique issue.

ComEd has plans to invest $2.6bn over 10 years to upgrade and improve the reliability of its system as part of the Smart Grid law.