Crashing at friend’s houses, blessing our gas stoves and plugging into trees, New Yorkers are all wondering -- why does it take the power so long to go back on?

Con Edison’s said it could take as long as four days to restore power in Manhattan, and as much as a week in the outer boroughs. For many of us, desperately trying to preserve the flickering life of a laptop or cellphone battery, that seems too long to ponder.

Here’s why it will take that long, whether we like it or not.

According to Virginia Tech professor and infrastructure expert Saifur Rahman, an electrical grid like New York’s has several key parts, each of which are essential to getting electricity to homes. First, there’s the generator -- a power plant that generates electricity for large swaths of the city. That power is then pushed, at very high voltage, across transmission lines -- thick bundles of metal cables that handle enormous amounts of juice. Power from transmission lines is then sent into transformers, machines that bring down the voltage of the electricity, before sending it into small distribution lines, which transport that electricity into our homes.

All of these pieces are uniquely vulnerable. “Power lines are underground in cable trenches, and if they get flooded, you have short circuit possibilities,” says Rahman. Small or backup power generators, he continues, are often in basements which flood and short-circuit the generators when a storm hits, and “substations that contain transformers are open air and they’re subject to storm damage.”

Storm damage to transformer wires can prevent the machines from detecting spikes in electricity coming from the transmission lines. This in turn causes circuits in the machine to overheat and melt. In the best case scenario, this puts the transformer silently out of commission, robbing homes of power but causing no immediate catastrophe. In the worst case, sparks released by frying circuits can ignite coolant within the transformer, causing a massive explosion.

Unfortunately, electrical grids don't work like the web: “On the internet,” says Rahman, “there is a mesh of networks which has multiple alternate paths to get your data from point A to point B in various ways. Electrical power systems are not built that way for many reasons, one is cost, so in many cases you have one primary route and maybe a secondary route and that’s it.” If the primary distribution route for electricity to a cluster of homes is down, Rahman says, the secondary route can get overwhelmed very easily, “and sometimes, in the case of New York, you may have lost the primary and the secondary.”

So, to summarize: we have a grid with many vulnerable parts, and each piece between your power plant and your home must be working correctly for you to get electricity. In a storm like Sandy, every part of the system can be damaged, and Rahman says New York City’s grid is particularly at risk: “it’s very densely populated, a lot of power has to go through those underground cables.”

Given all this, it’s not surprising that multiple types of breakages are being reported all over the city, from downed power lines in the outer boroughs to exploded transformers in downtown Manhattan. And for any particular residence to get its power back on, electrical workers have to first determine where in the system the blackout to that particular residence was caused before they can even think about making repairs -- repairs which could be anything from fixing a massive substation to pinning up a particular local power line.

Also, we're not first on Con-Ed's list.

Disaster analyst Philip Jan Rothstein explains: Power companies "have to perform triage... they have their priorities set by things like military, emergency services, police, medical, fire, so forth.”

Further complicating matters, much of the badly damaged infrastructure is still inaccessible because of winds and flooding. “There’s no telling when a steam line’s going to rupture or a water main’s going to break or something’s going to back up or a pump’s going to fail," says Rothstein.

In other words, Con Edison probably wants the power on quickly, but not so quickly that it puts their workers at risk.

Bottom line, says Rothstein, there’s probably no quick fix. The power companies, he says, "are good at this. They’ve got all kinds of protective measures, they’ve got all kinds of detectors they’ve got all kinds of contingency plans and backups and so forth,” but in a Sandy-style situation, “sometimes something breaks, sometimes something fails.”

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The Huffington Post is eager for insights from our community, especially people with experience in power, infrastructure and engineering, on the adequacy of emergency preparation in advance of Hurricane Sandy, and the degree to which past disasters have informed adequate planning and construction. Please send a note to sandytips@huffingtonpost.com with insights and suggestions for the important questions that need to be asked of relevant private sector and government officials, and point us toward stories that need to be pursued.

SEE: PHOTOS OF HURRICANE SANDY'S AFTERMATH

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  • A casket floated out of the grave in a cemetery in Crisfield, Md. after the effects of superstorm Sandy Tuesday, Oct. 30, 2012. Hundreds of people were displaced by floodwaters in Ocean City and in Crisfield. At the same time, 2 feet of snow fell in westernmost Garrett County, were nearly three-quarters of residents lost power. (AP Photo/Alex Brandon)

  • An ambulance is submerged in floodwaters in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012, in Hoboken, N.J. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • A vehicle drives on a flooded street in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012, in Hoboken, N.J. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • A firehouse is surrounded by floodwaters in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012, in Hoboken, N.J. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • A vehicle drives on a flooded street in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012, in Little Ferry, N.J. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • An emergency vehicle drives on a flooded street in Little Ferry, N.J. in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • An emergency vehicle drives on a flooded street in Little Ferry, N.J. in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • Rescue workers help stranded people out of their flooded homes in Seaside Heights, N.J., following the arrival of superstorm Sandy, Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Julio Cortez)

  • Rescue workers help stranded people out of their flooded homes in Seaside Heights, N.J., following the arrival of superstorm Sandy, Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Julio Cortez)

  • A runway at the Teterboro Airport is flooded in the wake of superstorm Sandy on Tuesday, Oct. 30, 2012, in New York. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Mike Groll)

  • Homes in Bethany Beach, Del. are surrounded by floodwaters from superstorm Sandy on Tuesday, Oct. 30, 2012. Officials said Bethany and nearby Fenwick Island appeared to be among the hardest-hit parts of the state. (AP Photo/Randall Chase)

  • Floodwaters from superstorm Sandy surround homes in South Bethany, Del. Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/The Wilmington News-Journal, Robert Craig) NO SALES

  • Floodwaters from superstorm Sandy surround homes in South Bethany, Del. Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/The Wilmington News-Journal, Robert Craig) NO SALES

  • Downed power lines and a battered road is what superstorm Sandy left behind as people walk off the flooded Seaside Heights island, Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Julio Cortez)

  • This photo provided by the Metropolitan Transportation Authority shows the South Ferry subway station after it was flooded by seawater during superstorm Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/ Metropolitan Transportation Authority)

  • Debris litters the beach north of Indian River Inlet in southern Delaware after waves churned up by superstorm Sandy demolished hundreds of yards of beach dunes and left state Route 1, the major north-south coastal highway, covered in sand. (AP Photo/Randall Chase)

  • This photo provided by the Metropolitan Transportation Authority shows the South Ferry subway station after it was flooded by seawater during superstorm Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/ Metropolitan Transportation Authority)

  • This photo provided by the Metropolitan Transportation Authority shows the South Ferry subway station after it was flooded by seawater during superstorm Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/ Metropolitan Transportation Authority)

  • Streets around a Con Edison substation are flooded as the East River overflows into the Dumbo section of Brooklyn, N.Y., as Sandy moves through the area on Monday, Oct. 29, 2012. After a gigantic wall of water defied elaborate planning and swamped underground electrical equipment at a Consolidated Edison substation in Manhattan's East Village, about 250,000 lower Manhattan customers were left without power. (AP Photo/Bebeto Matthews)

  • In this Monday, Oct. 29, 2012, file photo, Consolidated Edision trucks are submerged on 14th Street near the ConEd power plant in New York. After a gigantic wall of water defied elaborate planning and swamped underground electrical equipment at a Consolidated Edison substation in Manhattan's East Village, about 250,000 lower Manhattan customers were left without power. (AP Photo/John Minchillo)

  • Downed power lines and a battered road is what superstorm Sandy left behind as people walk off the flooded Seaside Heights island, Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Julio Cortez)

  • This photo taken Tuesday, Oct. 30, 2012, shows what appear to be transformers exploding after much of lower Manhattan lost power during hurricane Sandy in New York. After a gigantic wall of water defied elaborate planning and swamped underground electrical equipment at a Consolidated Edison substation in Manhattan's East Village, about 250,000 lower Manhattan customers were left without power. (AP Photo/Karly Domb Sadof)

  • Peter Andrews removes belongings from his father's beachfront home, destroyed in the aftermath of a storm surge from the superstorm Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. Andrews, 40, who was born in the house, said "we had a lot of storms and the only damage in the past was when a national guardsman threw a sandbag through the window." He added, the house was in the process of being sold. (AP Photo/Bebeto Matthews)

  • A small shop that rents personal water craft rests in a huge sinkhole on the bayside in Ocean City, N.J. Tuesday, Oct. 30, 2012 after a storm surge from superstorm Sandy Monday night. (AP Photo/Mel Evans)

  • A beachfront house is completely destroyed in the aftermath of a superstorm Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • The entrance to a beachfront house is destroyed in the aftermath of a storm surge from superstorm Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • A second floor closet is exposed in a beachfront house in the aftermath of a storm surge from Hurricane Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • People stop along the Brooklyn waterfront to photograph the Brooklyn Bridge and the Manhattan skyline, Tuesday, Oct. 30, 2012 in New York. Much of lower Manhattan is without electric power following the impact of superstorm Sandy. (AP Photo/Mark Lennihan)

  • Marcus Konner, 22, boards his home in the aftermath of a storm surge from Hurricane Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • People walk through the houses destroyed in the aftermath of yesterday's storm surge from superstorm Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • Carlo Popolano stands outside his beachfront home, damaged in superstorm Sandy, on Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. Popolano said he was watching the storm with his son and "everything was okay until about 7:30 and then one big wave came and washed away our whole backyard." (AP Photo/Bebeto Matthews)

  • A beachfront house is completely destroyed in the aftermath of yesterday's surge from superstorm Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • A backyard is inundated with floodwaters in the aftermath of Sandy, Tuesday, Oct. 30, 2012, in Lewes, Del. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Randall Chase)

  • A car is upended on a mailbox on Surf Avenue in Coney Island, N.Y., in the aftermath of Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Ralph Russo)

  • This handout photo provided by NOAA, taken Tuesday, Oct. 30, 2012, shows post-tropical storm Sandy off the East Coast of the US. Campaign 2012 is rich with images that conjure the seriousness and silliness that unfold side-by-side in any presidential race. Who could have predicted that a superstorm would overshadow and scramble the presidential campaign in its final days? President Barack Obama and Mitt Romney revised and re-revised their campaign schedules as Hurricane Sandy, a most unlikely October surprise, barreled up the East Coast and then roared ashore in New Jersey. (AP Photo/NOAA)

  • A parking lot full of yellow cabs is flooded as a result of superstorm Sandy on Tuesday, Oct. 30, 2012 in Hoboken, NJ. (AP Photo/Charles Sykes)

  • A beachfront house is damaged in the aftermath of yesterday's surge from superstorm Sandy, Tuesday, Oct. 30, 2012, in Coney Island's Sea Gate community in New York. (AP Photo/Bebeto Matthews)

  • A car is upended on a mailbox on Surf Avenue in Coney Island, N.Y., in the aftermath of Sandy on Tuesday, Oct. 30, 2012. Sandy, the storm that made landfall Monday, caused multiple fatalities, halted mass transit and cut power to more than 6 million homes and businesses. (AP Photo/Ralph Russo)

  • Damage caused by a fire at Breezy Point is shown Tuesday, Oct. 30, 2012, in New York. A fire department spokesman says more than 190 firefighters are at the blaze in the Breezy Point section. Fire officials say the blaze was reported around 11 p.m. Monday in an area flooded by the superstorm that began sweeping through earlier. (AP Photo/Frank Franklin II)

  • Fire still burns at the scene of a fire in Breezy Point, in the New York City borough of Queens Tuesday, Oct. 30, 2012, in New York. The fire destroyed between 80 and 100 houses Monday night in the flooded neighborhood. More than 190 firefighters have contained the six-alarm blaze fire, but they are still putting out some pockets of fire. (AP Photo/Frank Franklin II)

  • East Coast Begins To Clean Up And Assess Damage From Hurricane Sandy

    ATLANTIC CITY, NJ - OCTOBER 30: People stand on a mound of construction dirt to vew the area where a 2000-foot section of the 'uptown' boardwalk was destroyed by flooding from Hurricane Sandy on October 30, 2012 in Atlantic City, New Jersey. The storm has claimed at least 33 lives in the United States, and has caused massive flooding accross much of the Atlantic seaboard. US President Barack Obama has declared the situation a 'major disaster' for large areas of the US East Coast including New York City. (Photo by Mario Tama/Getty Images)

  • Homes damaged by a fire at Breezy Point are shown, in the New York City borough of Queens Tuesday, Oct. 30, 2012, in New York. The fire destroyed between 80 and 100 houses Monday night in the flooded neighborhood. More than 190 firefighters have contained the six-alarm blaze fire, but they are still putting out some pockets of fire. (AP Photo/Frank Franklin II)

  • East Coast Begins To Clean Up And Assess Damage From Hurricane Sandy

    ATLANTIC CITY, NJ - OCTOBER 30: A man walks over debsris where a 2000-foot section of the 'uptown' boardwalk was destroyed by flooding from Hurricane Sandy on October 30, 2012 in Atlantic City, New Jersey. The storm has claimed at least 33 lives in the United States, and has caused massive flooding accross much of the Atlantic seaboard. US President Barack Obama has declared the situation a 'major disaster' for large areas of the US East Coast including New York City. (Photo by Mario Tama/Getty Images)

  • East Coast Begins To Clean Up And Assess Damage From Hurricane Sandy

    NEW YORK, NY - OCTOBER 30: Ground Zero is seen on October 30, 2012 in the Financial District of New York, United States. The storm has claimed at least 33 lives in the United States, and has caused massive flooding accross much of the Atlantic seaboard. US President Barack Obama has declared the situation a 'major disaster' for large areas of the US East Coast including New York City. (Photo by Andrew Burton/Getty Images)

  • US-WEATHER-STORM-SANDY

    Sailboats rest on the ground after being tipped over by Hurricane Sandy on City Island October 30, 2012 in New York. US President Obama declared New York a disaster area. The death toll from superstorm Sandy has risen to 16 in the mainland United States and Canada, and was expected to climb further as several people were still missing, officials said Tuesday. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)

  • US-WEATHER-STORM-SANDY

    Boats rest on the ground after floating from their stands at dry dock on City Island , in New York October 30, 2012 following Hurricane Sandy's impact. US President Obama declared New York a disaster area The death toll from superstorm Sandy has risen to 16 in the mainland United States and Canada, and was expected to climb further as several people were still missing, officials said Tuesday. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)

  • Homes destroyed by a fire at Breezy Point are shown, in the New York City borough of Queens Tuesday, Oct. 30, 2012, in New York. The fire destroyed between 80 and 100 houses Monday night in the flooded neighborhood. More than 190 firefighters have contained the six-alarm blaze fire, but they are still putting out some pockets of fire. (AP Photo/Frank Franklin II)

  • US-WEATHER-STORM-SANDY

    Boats rest on the ground after floating from their stands at dry dock on City Island , in New York October 30, 2012 following Hurricane Sandy's impact. US President Obama declared New York a disaster area The death toll from superstorm Sandy has risen to 16 in the mainland United States and Canada, and was expected to climb further as several people were still missing, officials said Tuesday. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)

  • US-WEATHER-STORM-SANDY

    Residents look at damage left by Hurricane Sandy on City Island, New York, October 30, 2012. US President Obama declared New York a disaster area The death toll from superstorm Sandy has risen to 16 in the mainland United States and Canada, and was expected to climb further as several people were still missing, officials said Tuesday. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)

  • US-WEATHER-STORM-SANDY

    Boats rest on the ground after floating from their stands at dry dock on City Island , in New York October 30, 2012 following Hurricane Sandy's impact. US President Obama declared New York a disaster area The death toll from superstorm Sandy has risen to 16 in the mainland United States and Canada, and was expected to climb further as several people were still missing, officials said Tuesday. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)

  • East Coast Begins To Clean Up And Assess Damage From Hurricane Sandy

    NEW YORK, NY - OCTOBER 30: A truck drives through a flooded street, caused by Hurricane Sandy, on October 30, 2012, in the Lower East Side of New York City. The storm has claimed at least 33 lives in the United States, and has caused massive flooding accross much of the Atlantic seaboard. US President Barack Obama has declared the situation a 'major disaster' for large areas of the US East Coast including New York City. (Photo by Andrew Burton/Getty Images)


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