New York’s newest clean-power artery is already showing why grid planning hates single points of optimism.
The Champlain Hudson Power Express, a 339-mile underground and underwater transmission line from Quebec to Queens, began operating in May. On July 3, during a regional heat wave, New York imported 52 gigawatt-hours of electricity from Canada, according to the U.S. Energy Information Administration. That was enough to cover about 9% of the state’s electricity use that day, and some of it moved over the new line.
The project is not a decorative cable. Developers say it can eventually supply as much as 20% of New York City’s electricity demand, mostly from Quebec hydropower. For a city still tied to fossil-fueled generation, that is the kind of interconnection that can change dispatch decisions, emissions, and how much local capacity planners think they need to build.
Then the line went down.
CHPE has had two early outages. RTO Insider reported that the first, on July 1, was caused by a trip at a converter station on the Canadian side. A second outage began July 4, and the line was still offline on the morning of July 22.
Officials traced the later problem to damaged cable on the U.S. side of the border, RTO Insider reported. The cable manufacturer sent specialists to examine what happened. Hydro-Québec spokesperson Lynn St-Laurent said the damaged section had been removed and replaced, with remaining work and post-repair testing expected to finish by the weekend.
Some engineers are not treating the bumpy start as a scandal. Normand Mousseau, a physics professor at Université de Montréal, told the Montreal Gazette that large new power lines can run into startup problems because equipment is not fully tested until it is operating on the grid. That is not comforting, exactly, but it is less exotic than a mystery failure in a riverbed megaproject.
The project took a long time to get here. Planning began about 15 years ago, and the formal permitting process started in March 2010. Transmission Developers, owned by Blackstone, partnered with Hydro-Québec, which manages generation and transmission in the province. Construction started in late 2022 and finished earlier this year. The privately financed line cost $6 billion.
The engineering is bluntly physical: two high-voltage direct-current cables, each about five inches wide, buried underground or laid underwater across New York. Large portions run along the Hudson River bottom, where specialized vessels used water jets to cut trenches into the sediment for the cable.
The grid logic is straightforward. Quebec gets more than 99% of its electricity from renewable sources, mostly hydropower, with wind growing. New York has hydropower, nuclear and wind, but still gets most of its generation from fossil fuels. More transmission lets regions trade power rather than each building enough plants to solve every local peak alone. Research has found that stronger interconnection can reduce emissions and system costs.
New York was not counting on CHPE for this summer’s reliability. Kevin Lanahan, a spokesperson for the New York Independent System Operator, said NYISO planning studies did not assume the line would be available during the heat wave, and said reliability planning does not depend on one project.
That restraint looks prudent. A similar Quebec-to-Maine project, the 145-mile New England Clean Energy Connect line, opened in January and has also had outages, with little added energy flowing into the Northeast, according to Canary Media.
Even after the cable problem is fixed, CHPE has another constraint: water. Quebec has faced severe drought for the past three years, reducing the reservoirs that feed its hydropower system, according to the New York Times. A working line can move electricity only if there is electricity available to send.
This story draws on original reporting from MIT Technology Review.
