Before industry restructuring and creation of ISO New England in the 1990s, New England saw little investment in its transmission infrastructure, which resulted in congestion—system constraints that prevent the least-cost electricity from reaching certain locations and can threaten reliability. In 2006, the US Department of Energy labeled New England a Congestion Area of Concern.
Over the last 20 years, the ISO’s continuous study and analysis of the transmission system has helped guide cooperative regional investment to fix weak spots and bottlenecks on the system. After years of strong investment, New England now has a more reliable and flexible power system, costly congestion has been virtually eliminated, and the region is no longer a Congestion Area of Concern. (Learn more about ISO New England’s responsibility for power system planning.)
Based on the needs described in the ISO’s Regional System Plans, New England’s transmission owners have initiated projects reinforcing transmission-serving areas that have experienced significant load growth, such as northwestern Vermont. Projects have also been initiated in critical load pockets, such as Southwest Connecticut and Boston, allowing the import of power from other parts of the system. New interconnections with neighboring power systems also have been placed in service. Together, these interconnections enable the import of competitive and emergency supplies of electricity from New York and eastern Canada. The region met 17% of its energy needs with imported electricity in 2018.
Today, the ISO has implemented a process for finding competitive solutions to identified transmission needs in the region. These needs may relate to power system reliability, efficiency of wholesale electricity markets, or public policy goals. Learn more about the competitive transmission process in New England.
As of the October 2018 Regional System Plan Project List, 787 project components had been placed in service and an additional 82 projects were anticipated over the next 10 years to ensure that electricity continues to move reliably and efficiently across the region.
Because the electric grid is so tightly networked, each state shares in the benefits—and costs—of reliability upgrades to the transmission system. New England’s electricity consumers, who ultimately pay project costs, receive many benefits from this investment in the regional transmission system:
New England’s revitalized transmission system and more efficient fleet have driven striking decreases in congestion costs and uplift costs, called Net Commitment-Period Compensation (NCPC). Uplift represents payments to make sure a resource following ISO dispatch instructions is no worse off financially than in the best alternative generation schedule. Additionally, the ISO has not had to use special reliability contracts since 2010.
Higher market prices signal an investment opportunity for new, more efficient power resources to replace generators that are closing down and to displace those that are inefficient or expensive. As of January 2019, the ISO was slated to study over 150 grid-interconnection requests from proposed new generators, though many may not ultimately be built. (Historically, almost 70% of proposed new megawatts in the ISO Generator Interconnection Queue have ultimately withdrawn.) These proposals include nearly 13,500 MW of proposed new on- and offshore wind power. (Read more about proposed new resources in the region.)
Because of the large distances from some of the proposed onshore wind power projects to the existing grid, major transmission system upgrades will be needed to deliver more of this power to far-away consumers. Proposed offshore wind projects closer to New England load centers may require fewer upgrades to the existing grid, but building wind turbines offshore is typically more costly than placing them on land.
In February 2015, the ISO, after working with stakeholders, implemented improvements to the processes for evaluating the interconnection of ETUs and to incorporate ETUs into the Forward Capacity Market. ETUs are transmission lines funded by private parties—not through regional cost-sharing. While not necessary from a reliability standpoint, they can help enhance generator deliverability or facilitate the integration of renewable resources, such as remote wind resources, by enhancing portions of the grid.
A new “clustering” methodology will also go into effect in 2018 that allows interconnection requests from multiple generators and ETUs to be studied together. This will help move forward the requests in northern and western Maine, where thousands of megawatts of proposed new resources, mostly wind, are seeking to interconnect to the regional grid. It may also help generators save on interconnection costs.
As of January 2019, 17 ETUs were in the queue, totaling nearly 14,000 MW of potential transfer capability. They would deliver power primarily from large-scale hydro resources in eastern Canada and wind resources in northern New England.
Read more about the ISO’s responsibility for long-term transmission system planning on the Power System Planning page.