NEW YORK -- When Hurricane Sandy struck the East Coast, it flooded electrical substations and knocked down trees, shutting off power for 8.2 millions customers.

While the electric companies got that number down to 4.45 million as of Thursday, it will be days or even weeks before all the region's residents can turn their lights on. New York's ConEd said Thursday that recovery would take until Nov. 11 for most, but could stretch on until the end of the month.

Does the restoration of the mid-Atlantic power grid have to take so achingly long? While the utility companies argued that they're working as hard as they possibly can, several experts said that America's power infrastructure could be more resilient -- even when tested by a once-in-a-century storm.

"The message from Sandy is that it has to be stronger," said James Hoecker, a lawyer who led the Federal Energy Regulatory Commission under President Bill Clinton. Experts suggested various adjustments, such as underground cables, smart grid technology and tree trimming to make future outages end sooner.

Designing above-ground power lines to cope with more of a beating, and hardening critical infrastructure, could help. On the distribution side, most telephone poles and wires are not designed to withstand the 90-mile-per-hour winds that swept through New Jersey on Monday. That, said Otto Lynch, the energy representative for the American Society of Civil Engineers’ Committee on America’s Infrastructure, is a mistake.

"It is embarrassing to me that streetlights are supposed to be designed to a higher level of standard than distribution lines are," he told HuffPost. For perhaps $100 a pole, he argued, we could prevent a lot of downed electrical poles and powerless neighborhoods.

The transmission network, the part of the grid that moves power across state lines and has been implicated before in outages like the blackout of 2003, appears not to have been seriously tested by the storm because of its higher design standards.

But the grid could use some work, Lynch said. It was first built in the 1880s and many of its components are now more than 100 years old, designed for 50 years of life. If something like Hurricane Katrina, which was a Category 3 storm when it made landfall, had hit the New York-New Jersey area, transmission would certainly have been affected.

The solution? "It's called redundancy," Lynch said. "Basically what we need is more transmission lines." That will only occur if regulators and the public become more willing to allow those lines to be built even when they would not seemingly affect day-to-day electricity provision.

Another proposal: the comparatively unsexy but critical regulations around tree trimming. Downed limbs caused up to 90 percent of power disruptions for some utilities during Hurricane Sandy. Many states in the northeast, like Connecticut, have laws that require utility companies to submit ‘vegetation management’ plans, but these laws do not require tree trimming cycles or line clearance specifications.

A fix to the tree-trimming issue could be better training and assessment standards for determining which trees could pose a problem in a severe storm. A team at the International Society of Arboriculture is in the process of developing a qualification program for tree risk assessment and hopes it will launch next Spring.

Sharon Lilly, ISA’s educational goods and services director, hopes the program will be used by all sectors, including commercial, municipal and utility workers who are tasked with protecting the electric grid. Though programs like this could help improve the ability of utilities to identify potential risks, Lilly acknowledged that the issue will likely linger, if for no other reason than that people like trees. “I don’t think society is ready to remove all the large trees that could possibly strike a wire,” she said.

This summer, after a derecho -- an aggressive thunderstorm -- killed power for more than 1 million residents near Washington, the rallying cry was to move more electrical cables underground. A recent report commissioned by Maryland Gov. Martin O'Malley concluded that "selective undergrounding is an effective way to harden the grid."

The idea is that underground wires are less vulnerable to things like wind and fallen trees. Most opposition to undergrounding, as it's called, comes from cost, which could range from $6 to $20 million a mile. Lilly called it “the ultimate solution" that "the U.S. has been reluctant to invest in."

But almost all cables in downtown Manhattan, which is still dark, are already underground -- so what happened? "When you underground a line and it causes flooding, you get problems," Lynch said. "Undergrounding … is not the perfect solution."

While underground lines are less vulnerable, they can take longer to restore when they do fail (though ConEd said customers with underground service will have power as soon as this weekend).

What would make underground lines more resilient to flooding, said Virginia Tech professor Saifur Rahman, is moving buildings' connections to those cables -- cords, transformers and generators -- above flood level. "The cables are fine, but you connect them into your building's electrical circuit,," Rahman said. "Those connections … can never get wet."

The combination of underground cables with a rooftop connector is what kept Goldman Sachs lit up, Rahman said. Elevating such equipment in existing buildings would be pricey, he said, but fairly cheap in new ones. He said he hopes that the city will tweak its standards to require this practice for all buildings. But that's not quite what he saw happen in New Orleans. "They only moved the generator up in some cases," Rahman said. "This is the complacency we all live with."

One more idea is updating both transmission and distribution networks with so-called "smart grid" technology. The 2009 Recovery Act included some $4 billion for such technology with a wide range of aims: making it easier for solar and wind power generators to bring their product to market, making residential consumers' energy use more efficient, and improving the grid's reliability.

"The grid is in a state of transition and this is, I think, going to accelerate the transition, storms like this," said Peter Fox-Penner, principal of The Brattle Group, an energy consultancy.

Smart meters on the customers' side of the distribution network will help utilities determine when and to what extent people are going without power. When outages occur, electricity providers' control center maps are automatically updated.

Making the grid smarter could also open up what some environmentalists see as a holy grail of energy transformation, distributed power -- which means every house could have a solar panel on top. Fox-Penner said that could lessen the impact of distribution failures during severe weather events.

"No one thinks about the power grid as long as the lights turn on when you flip the switch, and that happens well over 99 percent of the time," said Fox-Penner. "But when it goes down, people start asking whether there's any better way to do it."

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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.