A new analysis by ISO-NE shows about 9,600 MW of offshore wind may be able to connect to the New England transmission system without triggering the need for upgrades.
The study also found connecting offshore wind to points of interconnection (POIs) closer to the Boston area than previously modeled could reduce the overall amount of transmission investment needed by 2050 by up to $4.1 billion.
The analysis builds on the findings of ISO-NE’s 2050 Transmission Study and is intended to “provide high-level information about system constraints” affecting offshore wind interconnection. (See ISO-NE Prices Transmission Upgrades Needed by 2050: up to $26B and ISO-NE Analysis Shows Benefits of Shifting OSW Interconnection Points.)
The updated analysis accounts for the finalized location of the Gulf of Maine lease area, which is located further south than ISO-NE assumed in the initial study.
By shifting two POIs from Maine to Massachusetts and one from Massachusetts to Connecticut, ISO-NE found the region could save up to $2.1 billion in a low-demand scenario (assuming a 51-GW peak in 2050) and up to $4.1 billion in a high-demand scenario (57-GW peak in 2050).
A spokesperson for ISO-NE noted that, after making the POI adjustments, the four transmission buildout strategies evaluated in the 2050 study all cost roughly the same, with any differences falling within the margin of error.
Also in the new analysis, ISO-NE screened 50 potential offshore wind POIs using three 2033 load snapshots. While the original 2050 study, which focused on peak load conditions, modeled offshore wind resources at partial capacity, the updated analysis evaluated system conditions with offshore wind resources operating at full capacity.
The RTO first analyzed the POIs in isolation to determine their interconnection capabilities. It found that 19 may be able to support a 1,200-MW interconnection without upgrades, three could support up to 2,000 MW, and one could support up to 2,400 MW.
ISO-NE said the results should be viewed as “best-case since the viability of each POI could only decrease when subjected to a full interconnection study with more detailed analysis, along with other non-electrical factors such as permitting and siting.”
“Up to 38% of the existing major coastal substations in New England studied may be electrically suitable for a 1,200-MW offshore wind interconnection without constructing any new transmission infrastructure and without upgrading any existing transmission infrastructure to address thermal concerns,” ISO-NE found.
While most substations would need upgrades to support a 1,200-MW injection, ISO-NE found the majority of POIs could facilitate a 1,200-MW wind farm with less than $100 million in transmission upgrades.
ISO-NE also conducted a “multiple-POI analysis” to evaluate how multiple interconnected projects operating at full capacity at different locations on the system would affect the grid.
It found the region could add up to 9,600 MW of offshore wind before risking curtailment during low-load periods. Minimum load concerns could be further exacerbated by continued growth of behind-the-meter solar resources, ISO-NE noted.
However, “if generator owners are willing to accept significant curtailment, or pair wind farms with substantial energy storage, more than 9,600 MW may be able to reliably connect without major upgrades,” ISO-NE said, adding that increasing exports from the region could also reduce curtailment.
