ISO New England Finds Deep Emissions Cuts Feasible but Costly Beyond 85 Percent Reduction Target

ISO New England Inc. on Sept. 15 released its 2024 Economic Study, New England’s Evolving Grid, showing that states across the region could potentially achieve 85 percent of their carbon dioxide reduction goals by 2045 with a mix of solar power, land-based wind, and short-duration energy storage. The findings reflect the grid operator’s modeling of possible system build-outs between 2033 and 2050 to evaluate pathways for reliable and cost-effective decarbonization.

Most New England states have pledged to cut emissions by at least 80 percent from 1990 levels by 2050, with some targeting complete decarbonization. The study emphasizes that reaching beyond 85 percent emissions reductions leads to steeply rising costs, largely because expensive zero-carbon dispatchable technologies are needed to handle extended cold snaps during winter months.

The analysis also highlights demand growth as a major driver of future costs. Prior to 2040, resources are mainly needed to meet climate policy requirements. Afterward, demand growth from electrification of heating and transportation significantly increases capacity needs, with the final 15 percent of electrification adding about 18 percent to system costs.

Land-based wind emerges as the most consistently cost-effective option across the study’s time horizon, while utility-scale solar photovoltaics support decarbonization in earlier years. Shifting peak winter demand also proves important: managing electric vehicle charging so that drivers charge during the day rather than at night could lower system costs by up to 12 percent, or $18 billion, by 2050.

However, the study warns of growing inefficiencies in deep decarbonization scenarios, as renewable energy increasingly faces curtailment. Batteries cannot shift enough energy across seasons to meet winter demand, leaving the system reliant on zero-carbon, fuel-based technologies like small modular reactors. Including such dispatchable resources, along with long-duration storage, reduces total system capacity needs by over 15 percent and improves cost-effectiveness.

ISO New England stresses that these results are based on modeled futures rather than concrete development plans. Still, the report provides a roadmap for how policymakers, utilities, and industry stakeholders might balance emissions goals with economic and reliability concerns as the region’s grid evolves.