Con Ed is five years late delivering a state-mandated study that would have helped the utility better prepare for outages caused by heat waves like the one New York City suffered last weekend.

The Climate Change Vulnerability study arose after environmental groups petitioned the state in the aftermath of Hurricane Sandy, when nearly two million New Yorkers went without power for as long as six days. As part of a 2014 settlement with New York State’s Public Services Commission, Con Ed agreed to assess how the city’s changing climate—increased humidity, longer and hotter heat waves, wind and other severe weather — would affect the electrical grid and other elements of its operations in the long-term.

According to Con Ed’s original timeline, the first chapter—on heat and humidity—should have been published by the end of 2014. It wasn’t. The following year, the utility told the state that it wouldn’t complete that chapter until 2016, and promised that the full $4 million report would be ready by 2018. That also did not happen.

Instead, the state’s Public Service Department approved a new timeline giving Con Ed until the end of this year to turn in the finished report to the state, according to John Chirlin, a spokesman for the department.

“They dragged their feet,” said Mike Gerrard, the director of Sabin Center for Climate Change Law at Columbia University, one of the groups that originally petitioned New York State to require Con Edison to plan for climate change after Sandy.

“Years went by. Memories faded and the urgency seemed to decline,” he continued. “It was always on their to-do list, but it took them a long time to issue the contracts, to hire the consultants, to get around to doing the study.”

And once the study is published, Gerrard said, that’s just the beginning.

“The next question will be are they willing to spend the money to carry out the recommendations of the study,” he said.

Indeed, even if Con Ed had completed that chapter as originally planned by 2014, it’s unclear if it could have averted the recent power outages. But last weekend was exactly the type of scenario the utility was supposed to be planning for.

Last weekend, many people were at home, blasting air conditioners and watching television, stressing the infrastructure in residential neighborhoods. At the same time, the grid was unable to meet that demand because the wires were so hot from the ambient temperatures.

On Sunday afternoon, Con Edison recorded its highest demand for electricity usage on a weekend, supassing 12,000 megawatts per hour, according to the utility company. (The highest demand the utility ever reached was over 13,000 megawatts on July 19, 2013. But that occurred on a weekday, when most people were at work in Manhattan, where the electrical grid is stronger.)

By Sunday evening, Con Ed preemptively cut power to some 30,000 Con Edison customers in Eastern Brooklyn. The utility explained their engineers had identified 3,000 customers in the area where power systems had failed, and their engineers determined another 30,000 were on the brink of losing service if the rest of the equipment failed. Rather than let that happen, they shut down service, which would be theoretically easier to restore once temperatures dropped.

“You can think about a heat wave as an invisible Hurricane Sandy, meaning that they both push the power grid to its limits,” said Yury Dvorkin, an assistant professor of electrical and computer engineering and New York University who specializes in electrical grids and climate resiliency. “Heat waves are more predictable in the sense that they don’t happen once in a while. They happen regularly.”

New York City is hot and getting hotter. Between 1971 and 2000, the city saw an average of 14 days a year with temperatures above 90 degrees. That number is expected to jump to between 23 and 29 days through 2020 and increase from there up to as many as 64 days a year by 2080, according to projections from a sweeping 2010 report from the New York City Panel on Climate Change. The number of days a year above 100 degrees Fahrenheit is expected to climb from an average of 0.4 to up to four by 2050 and as many as nine by 2080.

Alfonso Quiroz, a spokesman for Con Edison, wouldn’t comment on why the climate change report had been delayed, but said the utility regularly plans for extreme heat and spent $1.5 billion last year to upgrade transformers and replace underground feeder cables.

“That is something that’s an ongoing project for us. We’re always looking to see how we can make the system more robust,” he said. “After the summer time, that’s when we start planning for the summer after.”

Last year’s investments also went towards building battery stations in Ozone Park to serve areas of Brooklyn and Queens. The battery stations would be recharged during regular hours and discharge when demand for electricity spikes, according to the 2018 press release.

In addition, Con Edison has recently instituted a voluntary “demand response management” program. Participants get a discounted electric rate if they agree to let the utility to monitor their usage and dial it back when the grid is reaching peak demand.

While the $1.5 billion price tag might seem staggering to a lay person, Dvorkin, the NYU professor, said much of that appears to have gone towards routine maintenance just to assure the electrical grid keeps functioning.

“Those things [are things] that a utility does routinely anyway,” Dvorkin said. “That’s a fairly standard procedure.”

He said the measures that utilities need to take include installing thicker electrical wires, insulating cables, and changing the location of some equipment. In addition, Dvorkin said Con Edison needs to make more sizable investments to create micro-electric grids powered by different energy sources that can support limited geographic neighborhoods when the main grid is under stress.

Separately from the climate vulnerability study, the state has already approved $1 billion dollars in infrastructure improvements that specifically deal with storm surges and flooding like what happened during Hurricane Sandy, much of which is already in place.

And while Con Edison has been an easy target for politicians like Governor Andrew Cuomo and Mayor Bill de Blasio in the last few days, there are compounding factors that exacerbate the city's electric grid on days like Sunday.

“A lot of the cause of the high demand is the heat island effect, which is the function of decades of construction practices, a lot of it a result of appliance energy efficiency standards, which are mostly set by the federal government,” said Gerrard, the Columbia professor. “A lot of it was also the demand from the transit system.”

Gerrard added that New Yorkers have to play their part too.

“And some of it was consumers who don’t want to turn down their air conditioning when there are public appeals to do that.”