Transmission costs are one of the main drivers of rate increases in New England. A report on ISO New England’s 2024 electricity markets by Potomac Economics, the external market monitor for the ISO, found that the ISO had the highest transmission costs of any system operator in the country, more than double the average rates observed in the other regional transmission organizations.
While transmission costs are increasing in other parts of the country due to the need to integrate new renewable energy, this is not the case in New England. Instead, transmission investments in New England have been driven by the ISO’s reliability planning criteria, which are more stringent than those employed by other regional transmission organizations.
Fortunately, while expensive, these past transmission investments have “better prepared the system to integrate renewable resources in the future,” according to Potomac Economics.