The New England transmission grid could require up to $26 billion in upgrades to meet the electricity needs of 2050, according to a report released by the regional grid operator.
The report from ISO New England laid out a series of scenarios for policymakers to consider as they plan for a future with broad electrification of heating and transportation, as well as population growth.
The report, authored in collaboration with Electric Consultants Inc., only incorporated steady-state thermal analysis and did not include costs associated with anticipated distribution system upgrades.
ISO-NE found that transmission upgrade costs to serve an estimated winter peak load of 57 GW in 2050, up from 28 GW today, could cost $22-26 billion.
By incorporating peak load reduction strategies, and reducing peak load to 51 GW, transmission upgrade costs could be reduced to $15-17 billion. The load reduction showed that the total mileage of transmission overloads decreased by 30-40%.
In the near term, New England could need $6-9 billion in transmission upgrades to serve an anticipated peak load of 35,000 MW in 2035.
ISO-NE’s load and generation assumptions were based on the Energy Pathways to Deep Decarbonization report released by the Massachusetts in 2020.
The report assumed all oil, coal, diesel, and municipal solid waste resources would retire by 2035. The 2050 generation mix called for 56 GW of solar PV, 32 GW of offshore wind, 16 GW of natural gas, 5 GW of energy storage, 3 GW of onshore wind, 3 GW of nuclear, 2 GW of hydropower, 2 GW of pumped storage, and 772 MW of biomass.
ISO-NE did not advocate for a set of solutions to the region’s forthcoming transmission challenges, but the grid operator did identify concerns with a “high likelihood” of occurring.
Many load-serving concerns do not appear until 2040 or 2050, the grid operator said, allowing the region to spread the cost of upgrades over many years rather than addressing issues immediately.
Among the most urgent concerns, ISO-NE said a large number of transformer overloads were seen throughout the system, many of which are dependent on the location of generation and load at specific stations. Relocating new generators from 345 kV to 115 kV helped to eliminate some of the transformer overloads, but many still persisted, they said.
‘High-likelihood’ concerns
ISO-NE identified a series of “high-likelihood” scenarios that could plague the transmission grid in the coming decades. While the grid operator shared potential roadmaps to address the challenges, it did not make recommendations.
ISO-NE flagged the major 345 kV lines leading from Maine and New Hampshire south into Boston for a “significant number of very high overloads’ found in the study. The overloads were consistent across all three study years and appeared across both summer and winter peak snapshots.
Additionally, a significant number of overloads were seen on the 115 kV lines that lead into northwestern Vermont, around the city of Burlington.
ISO-NE also identified several thermal overloads seen in Southwest Connecticut beginning in 2035, and carrying through 2050, under the 57 GW load scenario.
