Maryland regulators ordered power companies such as Pepco to improve their systems to make them more reliable after storms.

The new rules, released Wednesday by the Maryland Public Service Commission, come in the wake of last summer's derecho, when about 992,000 customers statewide experienced outages and about 32 million hours of service were interrupted.

The commission will not make the utilities pay any fines for their performance last summer, when the storm blew through quickly with strong, straight-line winds, because it found that they did not violate the Public Utilities Articles or the Code of Maryland Regulations. However, the PSC said that "a significant and unsatisfactory disconnect exists between the public's expectations of distribution system reliability ... and the ability of the present-day electric distribution systems to meet those expectations."

The PSC ordered utilities to develop plans to harden the distribution system within five years, examine their staffing levels, improve communications and review how to reduce the duration of power outages to "acceptable" levels.

The commission ordered them to do cost-benefit analyses to create long-range plans on how best to restore power to 95 percent of their customers within 50 hours after an outage.

Pepco spokeswoman Myra Oppel said the company, which delivers power to 305,000 customers in Montgomery and Prince George's counties, said the company has received the report but hasn't had time to review it and will comment on it at a later date.

The fast-moving derecho struck late on June 29, blowing down trees, power lines and traffic lights, and knocking out power to hundreds of thousands of Washington-area residents, some for as long as a week.

The PSC order comes several weeks after Montgomery County officials learned they do not have the authority to take over Pepco's control of the county's electrical grid. County officials moved last year to see whether the county could take control of the grid because of Pepco's poor performance after major storms.