The New England power system is undergoing a major transformation as five of its six states commit to reducing carbon dioxide emissions by at least 80 per cent by 2050. This shift is driving a transition towards mostly renewable, carbon-free power generation, along with greater electrification of heating and transportation, significantly altering electricity supply and demand patterns.

The ISO New England (ISO-NE) recently released the 2050 Transmission Study: Offshore Wind Analysis final report, which examines the reliable integration of large-scale offshore wind (OSW) projects into the regional grid, assessing their impact on the transmission system and identifying strategic planning requirements for future development. The findings of the report are based on N-1 direct current (DC) thermal steady-state analysis, providing a high-level view of system constraints but not replacing the need for more detailed full interconnection studies.

The report found that up to 38 per cent of major coastal substations in New England are potentially electrically suitable for a 1.2 GW OSW interconnection without the need for new or upgraded transmission infrastructure to handle thermal concerns. This means that, if optimally sited, around eight 1.2 GW OSW projects (totalling 9.6 GW) could connect and operate at full capacity simultaneously without significant curtailment. Additionally, the study revealed that up to 86 per cent of the substations examined may support OSW connection, although some would require upgrades. A smaller subset of these substations could potentially accommodate a 2 GW OSW project without new infrastructure.

The analysis also suggests that relocating OSW points of interconnection further south, from Maine to the Boston area, could achieve significant cost savings by reducing the necessity for new transmission upgrades. However, the North-South and Maine-New Hampshire transmission interfaces would still require enhancements due to electrification-driven load growth and increased generation in northern New England. ISO-NE emphasised that a holistic, regional planning approach, rather than incremental, individual wind farm development, could optimise cost savings and grid efficiency as New England progresses in its clean energy transition.

The full report can be accessed here.