Commonwealth Edison has investigated its distribution network and found it to be inadequate.

David Helwig, senior vice president with ComEd, said: "The outages during the summer revealed that we have substantial problems. The issue isn’t about generating enough power, its about not being able to deliver it."

So far, ComEd has carried out an initial survey which was critical of the system. It carried out 4346 inspections and completed 2300 repairs on its distribution network. The utility is continuing with its inspection programme. So far, the investigation has cost $20 million.