Report Finds $500M in Cost Savings and Reduced Environmental Impacts and Risk with Planned Offshore Wind Transmission for New York

A new report on offshore wind transmission by economic consulting firm The Brattle Group finds electric grid cost savings of over $500 million and significantly reduced environmental impacts and project risks in developing a multi-user, planned transmission system for offshore wind in New York. The report, Offshore Wind Transmission: An Analysis of Options for New York, evaluates the challenges of connecting each wind farm to shore individually in comparison to a planned approach—a high-capacity offshore wind transmission system serving multiple wind farms, reducing marine cabling, and optimizing onshore landing points and electric substations.

Brattle's research, supported by engineering firms PTerra and Intertek, underscores the pivotal role of transmission planning in the development of New York's offshore wind industry. The approach of relying on individual generator lead lines would require extensive onshore grid upgrades costing four times as much as a planned approach. By using fewer cable routes and more robust grid connections, a planned transmission system reduces grid congestion and the need for expensive, disruptive onshore transmission upgrades, thereby also reducing the impacts on the marine environment and coastal communities.

"Substantial additional offshore wind development will be necessary to achieve New York's clean energy goals," said Johannes Pfeifenberger, a Brattle principal and a study coauthor. "At the scale considered by New York, a planned approach to offshore transmission will significantly reduce the environmental footprint and the overall costs and feasibility risks of offshore wind generation."

Among the report's other findings:

• Planned offshore transmission significantly reduces seabed marine cabling. A planned transmission approach would reduce cabling by almost 60%, preventing 660 miles of seabed disturbance and significantly reducing impact on fisheries and marine ecosystems.
• Planning and procuring transmission separately from generation increases competition and can reduce transmission costs 20–30%, according to studies of UK offshore transmission and US onshore transmission trends. It also increases competition for offshore wind generation.
• Planned transmission would more fully utilize offshore wind lease areas and more easily reduce offshore wind curtailment. A planned transmission approach utilizing more efficient direct current technology would deliver more power to shore than alternating current technology. In an unplanned system, after each developer interconnects the bulk of their lease site, it may be cost-prohibitive to interconnect the residual areas in the lease, underutilizing potential wind power.

"Developing a shared ocean grid is critical to achieving New York's ambitious offshore wind goals," said Kevin Knobloch, President of Anbaric's New York OceanGrid. "The next phase in achieving New York's goals depends on building transmission infrastructure in a way that reduces overall costs and feasibility risks, protects fisheries, coastal communities and the environment, and enables developing the offshore wind industry to scale."