Could hydropower hamper NYC’s building decarbonization law?

A new wrinkle is emerging in New York City's Local Law 97, which requires owners of large buildings to cut their emissions over time. Starting as soon as next month, building owners will be able to buy renewable energy credits (RECs) instead of making their properties more efficient. The credits come from the Champlain Hudson Power Express, a transmission line that began delivering Canadian hydropower to the city in June. Owners can buy the credits from the New York State Energy Research and Development Authority, with the money helping pay for the power line.

Climate groups and some City Council members worry the credits will be cheaper than the law's penalties, letting building owners avoid real upgrades like better insulation or heat pumps. One analysis found RECs could offset up to half of the emissions over the law's 2030 limits, and as much as 85 percent for office buildings. A City Council bill would cap RECs at 10 percent of a building's electricity emissions, but Mayor Mamdani, who criticized the credits as a candidate, hasn't yet said whether he'll support the limit. Others argue the credits are helping fund cleaner power for the whole grid, not just letting owners off the hook.

This mainly affects owners of large commercial and residential buildings covered by Local Law 97, not typical single-family homeowners. But it's a reminder that as cities and states set climate rules for buildings, the details of how compliance works — including credits like these — can shape whether efficiency upgrades actually happen or get delayed.