Pepco has promised to restore power to 90 percent of the customers who lost it as a result of Friday night’s storms by Friday, July 6, at 11 p.m., but tens of thousands of customers may not see their electricity return until even later.

As of 1 p.m. Sunday afternoon, more than 345,000 Pepco customers in Montgomery County, Prince George’s County and the District were still without power, the company reported.