Mayflower Wind is seeking to amend an 804-MW offshore wind power purchase agreement with Massachusetts’ utilities to reflect a change in the project’s interconnection point to land. The new location will allow Mayflower to reduce the original project bid price by about 10%.
The joint venture of Royal Dutch Shell (NYSE:RDS.A) and Ocean Winds North America, itself a joint venture of EDP Renewables and ENGIE, wants to interconnect the project at Brayton Point, about 50 miles west of the original interconnection point on Cape Cod, according to May 25 testimony to the Massachusetts Department of Public Utilities by Katherine Wilson, manager of long-term clean energy supply at National Grid (Dockets 20-16, -17, -18).
Eversource Energy (NYSE:ES), National Grid (NYSE:NGG) and Unitil (NYSE:UTL) selected the project in a 2019 OSW solicitation, and the department approved the utilities’ PPAs in 2020 for an initial 408-MW phase and a second 396-MW phase.
A change in the project’s interconnection point stems from the developers’ winning a 405-MW project bid in the state’s latest OSW procurement round last year, which includes interconnection at Brayton. Mayflower plans to build common offshore transmission infrastructure to serve the 804-MW project and the 405-MW project, Wilson said. Doing so, she added, would enable other project interconnections at the original site on Cape Cod, where ISO-NE has determined that only up to 1,200 MW of interconnection capacity is available based on planned system upgrades.
The two projects that Mayflower plans to interconnect at Brayton are in a 127,000-acre lease area (OCS-A 0521) that the developers say has 2 GW of generation potential.
Mayflower’s PPAs for the two phases of the 804-MW project allowed for a maximum price of $77.76/MWh, with potential to adjust the price down based on the developers’ ability to qualify for investment tax credits in the future. The maximum price is based on Mayflower receiving a 12% tax credit, and the PPA allowed for a minimum price of $70.26/MWh should a change in law provide for a 30% credit.
By combining the interconnection points at Brayton, Mayflower said it can lock in a price of $70.26/MWh, thereby eliminating ITC uncertainty. Currently, OSW projects that begin construction by the end of 2025 are eligible for a 30% ITC.
Mayflower’s change to the interconnection includes delaying the commercial operation dates (CODs) for the two phases of the 804-MW project by 18 months, according to a joint motion to amend the PPAs filed by the utilities. The CODs for the two phases would change from February 2026 to September 2027, and from June 2026 to December 2027, respectively.
Eversource, National Grid and Unitil filed a petition May 25 with the DPU (Docket 22-72) for approval of a PPA with Mayflower for the 405-MW project awarded last year. Under that PPA, Mayflower would place the project into commercial operation in March 2028.
