According to a report released by ISO New England (ISO-NE) on July 29, 2022, the grid operator’s reserve margin may need to increase from 15% to 300% by 2040 under some scenarios as more renewables are added to the grid and dispatchable generation is retired.[1] The Future Grid Reliability Study (FGRS), requested by New England Power Pool stakeholders, modeled a variety of decarbonization scenarios through 2040. The deep decarbonization scenario is based in part on assumptions used in Massachusetts’ 2050 Deep Decarbonization Roadmap Study. It includes the addition of 16 GW of offshore wind, 28 GW of solar, 600 GW of battery storage systems, and new transmission. Under this scenario, heating and transportation make up 20% and 18.6% of the grid operator’s total load, respectively.

In a modified deep decarbonization scenario where reliability criteria are met using only solar, wind, and storage, the transmission system would be challenged and would require 89,900 MW of those resources. Currently, ISO-NE has only 5,600 MW. The report concluded that ISO-NE “may require a significant amount of gas or stored fuels to support variable resources.” The report also found that the addition of new transportation and building electrification loads as part of decarbonization efforts will shift the grid to a winter-peaking system and require changes to planning processes. ISO-NE plans to issue a trio of appendices later in 2022 to address production cost, ancillary services, and resource adequacy. The second phase of the FGRS will consider the role of wholesale electricity markets.

[1] https://www.iso-ne.com/static-assets/documents/2022/07/2021_economic_study_future_grid_reliability_study_phase_1_report.pdf