A once-in-a-generation arctic blast hit the Northeast last weekend. The weather system sent temperatures plunging across the region, including in New York and Quebec, with a resulting increase in demand for electricity to keep homes warm. And therein lies the seeds of a future energy mystery. 

New York and Quebec have a long history of sharing electrical power, as both are part of the Northeast Power Coordinating Council, an interconnected electrical grid. And New York has inked an agreement with Hydro-Québec to bring power to New York City via the Champlain Hudson Power Express (CHPE), a new transmission line. 

The CHPE will bring 1250 megawatts of electricity directly into New York City, allowing it to turn off some of its fossil fuel generators in favor of hydro power that doesn’t emit greenhouse gases or particulate matter.  

But that assumes there is enough power available for export, and it is no secret that the agreement does not obligate Hydro-Québec to provide power in winter. 

Which brings us last weekend’s brutal cold snap.  

Almost two-thirds of homes in Quebec are heated using electricity, compared to less than 15 percent in New York. 

Anticipating high demand, Hydro-Québec asked people to take steps to limit their electricity usage, including turning down the heat in their homes, minimizing use of hot water, postponing use of large appliances, and even staying in bed under the covers on Saturday morning.  

That’s all good advice, but it indicates that Hydro-Québec was worried about having enough electricity to keep the heat on – and that’s without sending any to New York City yet. As it turned out, demand across the province hit a record 42,700 megawatts, smashing the old record of 40,500 megawatts set just a year ago. 

So how much power did that leave to potentially send to New York City, where temperatures dropped to near zero? 

As it turns out, less than none – Quebec actually had to import electricity to meet its demand, and one of the sources of its imported power was . . . New York. Ironically, the province at one point was importing 1,200 megawatts of power from New York and Ontario, almost exactly what it plans to send South through the CHPE.  

That means in a future arctic blast, when the CHPE is on-line and New York City needs help staying warm, Hydro-Québec may be around 2,400 megawatts short of meeting demand.  

Where the City will get its power from then is uncertain. Offshore wind will be coming on-line, but it’s undependable. Last weekend, overall wind power production in New York declined as the arctic cold swept in.  

The state will have more solar power, too, but there is no guarantee the sun will be shining when needed, and it certainly will not be available in the evening when people go home from work and crank up the thermostat. 

And by then we may have shut down most, if not all, of the highly reliable fossil fuel generation in the state that kept the heat on last weekend. 

If that’s not enough, electrical demand in the future will be higher than it is now because the City, as well as the state, plans to transition ever more buildings to electric heating. Every building that moves from gas or oil heat adds to the future electricity demand for which there is no guaranteed source of supply. 

The CHPE will provide the City with clean energy most of the year, so perhaps the project is worth the cost. But when there’s a killing cold like last weekend, Hydro-Québec simply may not be able to send any power down the line. 

What will keep Gotham warm then?