BOSTON, August 7, 2026 – London Economics International LLC (“LEI”) has released an independent study examining the feasibility, costs, and benefits of New Hampshire withdrawing from ISO New England (“ISO-NE”). The report, commissioned by the New Hampshire Department of Energy in response to House Bill 690, concludes that exiting from ISO New England would be complicated and likely increase electricity supply and transmission costs for New Hampshire customers.
LEI determined that while the New Hampshire state has theoretical abilities to direct Transmission Owners within the state to withdraw from ISO-NE and other associated entities such as New England Power Pool (“NEPOOL”), it would require New Hampshire to replace critical functions currently performed regionally by ISO-NE, including grid operations, wholesale market administration, and transmission planning. A successor framework would also remain subject to federal jurisdiction and applicable federal and regional reliability requirements.
“Our analysis shows the myriad complexities of affecting change in the membership of utilities inside a regional transmission organization, and the importance of looking at the impacts on customers holistically,” said Julia Frayer, LEI’s Managing Director. “New Hampshire could see lower wholesale energy costs under the modeled exit scenario, but those savings are outweighed by higher transmission, operating reserve and capacity costs. Furthermore, there is significant uncertainty around the cost of the legal process to negotiate an exit, and new institutions that would need to be stood up to take over reliability and grid operating functions currently performed by ISO New England.”
The report is available through the State of New Hampshire’s website here.
London Economics International LLC is a global economic, financial, and strategic advisory professional services firm specializing in energy and infrastructure, with extensive experience advising on wholesale market rules, auction design, competitive procurements, economic evaluation of infrastructure assets and market analysis. For further information on LEI, please contact Julia Frayer at (617) 933-7221 or visit www.londoneconomics.com.