Last Tuesday when a storm ripped through the Philadelphia area, more than 400,000 people lost power. For some, the inconvenience lasted a few hours, or even a few minutes. For many, a couple hundred thousand, the outage lingered for a day or two. By Friday, that number had been reduced by more than half. And as of Sunday night, power had come back to all but a few hundred people who get power from PECO or PSE&G, according to outage maps from those providers. Atlantic City Electric wasn’t faring as well. Nearly 10,000 of its customers still didn’t have power, according to its outage map.

Why does it take so long for power to be restored in some cases? What caused all these problems? Thetelegraphfield, with input from PECO’s Cathy Engel Menendez and PSE&G’s Karen Johnson, explains why power goes out and what the companies have been doing to get their customers’ lights back on.

So, why isn’t my power on?

The storm probably knocked down a tree limb onto a power line that at some point connects your house to the main power grid. Fallen limbs or fallen trees in general are the biggest cause of outages after storms like Tuesday’s. Strong winds or lightning strikes can also lead to power outages but that’s less likely.

And this power thing is complicated. It’s possible the tree wasn’t even in your neighborhood or even close to your neighborhood. The tree that’s forcing you to read books by candlelight might have fallen blocks or miles away and hit a power line that was connected to the system that feeds your home. There might even have been damages to the lines that pump power to your home in four, five or six places. Your power can’t be restored until all those problems are solved. And that can take a long time.

Give me an IRL example of how those problems get fixed

Engel Menendez said Concordville, out in the ‘burbs, sustained some particularly severe damage Tuesday night. About 12 trees fell, ruining or damaging 50 power lines. All of those trees had to be removed. Then utility poles had to be repaired or replaced — and the same is true for the power lines. Then the company must test everything to make sure the system works. It’s possible that process would need to be completed in multiple locations before your power is back.

OK, ok, that makes some sense. But seriously, why isn’t mine back on?

You’re probably extra unlucky. The power companies prioritize fixing the damages that can solve many people’s problems all at once. Johnson said if repairing a particular line will bring back service to hundreds of people, PSE&G will do it before it starts on fixing something that would benefit only a few customers. “For example,” Johnson said, “if a tree came down right adjacent to your property and brought your service line down, it’s going to take us longer to make that repair because we have to send an individual crew, truck and a tree trimmer to your location.”

The people who don’t have power at this point likely have a problem that is affecting their home only or maybe a few people’s homes.

Who’s working to fix my power?

At PECO, everybody. When major outages hit, the company goes into emergency response mode, and its 2,800 employees’ schedules change so that many work 12 to 16 hour shifts and people are working at all hours of the day and night. PECO also contracts extra workers to help on the ground, with more than 1,500 coming from Baltimore, West Virginia, New York, Ohio and beyond.

How bad was this storm for PECO and PSE&G?

Bad, but it could have been much worse. Tuesday’s storm resulted in the loss of power for 260,000 PECO customers and 130,000 PSE&G customers. PECO, which services 1.6 million people in Philadelphia, Bucks, Delaware, Chester, York and Montgomery counties, had 750,000 customers lose power after a February 2014 ice storm. About half of its customers lost power after Hurricane Sandy.

Mark Dent is a reporter/curator at thetelegraphfield. He previously worked for the Pittsburgh Post-Gazette, where he covered the Jerry Sandusky scandal, Penn State football and the Penn State administration. His...