A record-high number of “reportable outage events” impacted electric utility customers across Pennsylvania last year.

The Pennsylvania Public Utility Commission released its Electric Service Reliability Report Tuesday.

The annual report details performance benchmarks and standards for the state’s 11 electric distribution companies, including Citizens’ Electric, Duquesne Light, Metropolitan Edison, PECO, Pennsylvania Electric, Pennsylvania Power, Pike County Light & Power, PPL Electric Utilities, UGI Utilities, Wellsboro Electric and West Penn Power.

According to the report, there were 50 reportable outage events during 2017 — the highest number since PUC began collecting data in 1993, and a substantial increase from 2016, when only 20 outage events were reported. The size and scope of those storms is also noteworthy, with 2017 storms disrupting power to 1.3 million customers — which is nearly twice the figure for 2016 and more than double the 2015 total.

Under the Public Utility Code, an outage event is a service disruption involving 5 percent of total customers or 2,500 customers, whichever is less, for six or more consecutive hours.

Nearly all the 2017 outage events were triggered by severe spring and summer thunderstorms, which brought high winds and heavy rain. This is different from previous spikes in outage figures that were driven by a small number of high-impact storms like Hurricanes Irene (2011) and Sandy (2012), or Winter Storm Nika (2014).

Kurt Blumenau, PPL spokesman, said that PPL customers experienced an exceptional year for reliability in 2017 because of a variety of factors, including comprehensive tree trimming and clearing along power lines, investments in smart grid technology, and replacing older lines and equipment.

“We’re making the grid more storm-resistant, more dependable and more resilient than ever,” Blumenau said.

“In 2017, we reached benchmark performance in all areas except one, where we missed the target by one minute,” Blumenau said. “Top reliability is always our goal, and we’re working hard in 2018 to meet our benchmarks in all areas.”

Blumenau said that PPL continues to perform extensive work to ensure strong reliability for customers, such as trimming trees; installing new, stronger poles and wires; replacing aging equipment; and adopting new technology like smart grid, which can automatically restore power within minutes of an outage.

He said more information on PPL’s reliability work is available on pages 21-24 of the PUC’s report.

Blumenau said PPL is not releasing comparable reliability information for this year, but will report it to the PUC for next year’s report.

“We’re committed to providing safe, reliable and affordable electric service to all the people and businesses we serve,” he said.