By JON CHESTO

As the blizzard's fierce winds raged outside, the electric grid operators at ISO New England's headquarters in Holyoke realized they were in for a long night.

They watched the control room’s tennis court-sized main screen, tracking the outages one by one. Transmission lines and power plants dropped off the grid at a fierce pace. They quickly made calls to get other power plants running, but those plants were having trouble buying the natural gas they needed.

By the time the sun broke through the clouds the next morning, on Feb. 9, disaster had been averted: The system operators again had found ways to meet New England’s electricity needs. It would be up to the electric utilities to restore the hundreds of thousands of homes that lost power from downed lines. But at least ISO New England could ensure that there was enough high-voltage juice on the grid.

“It was an extremely delicate situation where we were wondering whether we would have enough resources to balance the system,” said Vamsi Chadalavada, ISO New England’s chief operating officer. “(The event) highlighted how critical it is to have sufficient fuel in New England to get us through storms and cold spells.”

To ISO New England executives, this was just another close call brought on by a fundamental problem with the region’s power market. (A similar, less dramatic rescue took place a couple weeks earlier when pricey gas was imported from Canada during a cold snap.) Roughly half of the region’s electricity generation relies on natural gas. But the two pipelines that bring low-cost shale gas from the west and south into New England are pushed to their capacity on cold days.

A report released in December by the New England States Committee on Electricity, a group of state regulators, argues that this reliance on natural gas will pose reliability risks to the region's electric grid if left unaddressed. Higher-cost imported gas may be available on the spot market during future cold stretches, but Chadalavada says the use of that gas could eventually contribute to price increases for homeowners and businesses. The U.S. Energy Information Administration reported last month that New England already has the highest natural gas prices on the spot market in the country, largely because of the pipeline constraints. The spot-market price for gas flowing into the Boston area on Feb. 13 was $17.85 per million British thermal units, more than five times the $3.28 per mmbtu price quoted at the Henry Hub, the country's primary pricing point.

“This is the single most important energy issue facing the region today,” said PowerOptions CEO Cynthia Arcate, whose Boston-based consortium buys power on behalf of nonprofits. “How we solve it is going to have ramifications for many years into the future, both in terms of cost and in terms of reliability.”

These pipeline constraints didn’t arrive overnight. In 2000, natural gas fueled 15 percent of New England’s electricity generation. Today, that figure is over 50 percent.

To some extent, this was due to oil and coal plants being used less frequently as new environmental rules made it more expensive to burn those fuels. But the main reason was simple: Natural gas became much less expensive as a new technique known as fracking unlocked vast domestic reserves, including in the nearby Marcellus Shale that stretches across much of Pennsylvania. The availability of cheap gas also prompted thousands of New England homeowners to switch their heating systems from oil to gas in recent years, putting an added demand on the pipeline. (Utilities’ heating customers typically get priority for New England’s gas supplies over the power plants.)

There could be enough gas in Marcellus to last for decades. But it didn’t take long for New England to max out on its capacity. There are only two pipelines bringing Marcellus gas to New England, Spectra Energy’s Algonquin line and a line operated by Kinder Morgan’s Tennessee Gas division. Both firms would like to expand their pipeline infrastructure here. But they need long-term contracts with gas buyers to finance those projects.

So for now, New England will have to use some expensive imported gas in times of need. It’s the equivalent of having a direct pipe to the Quabbin Reservoir for your home, but occasionally using spring water from the Fiji islands because that pipe is full. “Having such a source close to our doorstep but not being able to access it is an extreme cost to consumers, and the past several weeks have demonstrated that in spades,” Chadalavada said.

ISO New England is already embarking on a series of changes to the power market to address the issue. The grid overseer, for example, on Feb. 7 asked the Federal Energy Regulatory Commission for a change to better align the wholesale gas and electric markets here. In the longer term, ISO New England wants to alter one of its key pricing systems to reward plant operators that provide power when called upon and penalize those that don’t.

It’s not clear, though, if those changes will be enough to eventually prompt an expansion of pipeline capacity.

Dan Dolan, president of the New England Power Generators Association, said his group’s members don’t want to be forced into costly long-term contracts. “I don’t think there is ... a raw gas supply issue,” said Dolan, noting that the pipelines from Canada aren’t nearing capacity. “It’s that market dynamic of wanting to have more of that really cheap stuff.”

Robert Rio, senior vice president at the Associated Industries of Massachusetts, said he's frustrated that state officials aren't being more proactive. He said he blames the Patrick administration's inaction, in part, on a desire to promote renewable energy: "We're not going to be able to take (full) advantage of the best, cheapest gas coming out of the United States. ... At some point, we're going to hit the wall, and hitting the wall should not be an option."

Jonathan Peress, clean energy director at the Conservation Law Foundation, favors a balanced approach. He said there’s room for improvement by making sure that the region’s gas storage facilities are used effectively. A costly pipeline project, he said, could drive up electricity bills for consumers needlessly if less expensive alternatives aren’t pursued first. “We need to make sure we’re using the existing gas infrastructure to its maximum efficacy,” Peress said. “There is a risk that we could overbuild and create more of a cost burden.”