Tier 4 Program: Clean, Renewable Energy for New York City

New York City consumes nearly one-third of New York State's electricity, but for decades transmission constraints prevented the city from accessing the State's abundant renewable energy resources—leaving more than 90% of New York City's electricity supplied by fossil fuel generators. NYSERDA's Tier 4 Program was created by the New York State Public Service Commission to address this constraint, by procuring renewable energy certificates (RECs) derived from clean energy delivered directly into New York City through new transmission infrastructure. The program's contract [PDF] is for the Champlain Hudson Power Express (CHPE) project, which reached commercial operation on May 13, 2026, making it eligible to deliver clean hydropower from Hydro-Québec in Canada to New York City.

What is the Champlain Hudson Power Express?

The Champlain Hudson Power Express is a 1,250-megawatt High Voltage Direct Current (HVDC) transmission line running 339 miles from Montreal, Quebec to the Astoria Energy Complex in Queens, New York. It is the longest fully buried transmission line in North America.

Rather than running overhead, the line was strategically buried underground and underwater to increase long-term reliability and minimize environmental and community impact. Because it is primarily underground and underwater, it is less vulnerable to severe weather and other risks that affect traditional overhead transmission lines.

With an expected operational life of 60 to 80 years, the benefits of CHPE will continue well beyond the term of NYSERDA's 25-year contract.

CHPE Construction

Construction of CHPE began in November 2022 with oversight from the Department of Public Service, which coordinated with state agencies under a New York State Article VII permit. The project entered commercial operation on May 13, 2026—a remarkable on-schedule achievement for a project of this size and complexity.

CHPE was built with a strong commitment to domestic supply chain sourcing, using US-based manufacturers for high-volume infrastructure components including custom concrete vaults, conduit systems, and structural steel. The specialized HVDC cables were produced in both the United States and Norway. Following substantial completion, the project underwent a rigorous testing and commissioning phase. This included comprehensive electrical stress testing between Montreal and New York City, to help maintain long-term reliability and readiness to operate within the New York Independent System Operator (NYISO) energy market.

The scale of the construction effort reflects the project's significance:

• 339 miles of total transmission line, the longest fully buried line in North America
• More than 192 miles of underwater cable across Lake Champlain, the Hudson River, and the Harlem River
• More than 147 miles of terrestrial installation buried along existing railroad and highway rights-of-way
• More than 50 miles of horizontal directional drilling to avoid sensitive areas and existing infrastructure
• New converter stations completed in Astoria, Queens and Hertel, Quebec
• Approximately 1,400 union jobs at peak construction, requiring 7 million man-hours over three years

For further information on CHPE's construction activities, visit the CHPE website or search the New York State Department of Public Service DMM system for Article VII permit filings under Case 10-T-0139 . Terrestrial restoration activities are expected to be completed in Fall 2026.

What NYSERDA's Tier 4 Contract Does

NYSERDA does not purchase electricity delivered by CHPE. Instead, it procures the renewable energy attributes—called Tier 4 Renewable Energy Certificates, or Tier 4 RECs—that are associated with the clean energy delivered into New York City.

Tier 4 RECs are only procured after qualified renewable energy has been verified as delivered into NYISO Zone J. The process requires hourly matching where the generation, scheduling and delivery must all be verified on an hourly basis before a REC is minted. This ensures that the clean energy credited to the Tier 4 program is the same clean energy attributed to the New York City delivery.

The verification and payment process:

1. Using independent and proprietary data, NYSERDA verifies that eligible clean energy generation is hourly matched to final energy delivered over the CHPE line into Zone J
2. Once verified, Hydro-Québec imports the associated RECs from a compatible tracking system into the New York Generation Attribute Tracking System (NYGATS)
3. NYGATS mints one Tier 4 REC for each megawatt-hour of eligible renewable energy verified as delivered into Zone J
4. NYSERDA issues payment to Hydro-Québec following receipt of the Tier 4 RECs

The Tier 4 Implementation Plan [PDF] provides the administrative framework for tracking Tier 4 RECs, and their purchase and sale.