Background
Nationwide, the electric grid is experiencing rapid growth in demand. There is a greater need to integrate new, clean generation resources, such as solar and storage to help address the increased demand. Large investments in electric infrastructure will be needed to meet rising demand and to decarbonize the grid. According to ISO New England, Inc. (ISO-NE), transmission grid investments could reach $26 billion by 2050 (refer to the 2050 Transmission Study). Advanced transmission solutions, such as dynamic line ratings and advanced power flow controls (see below for more information), could offer an opportunity to use the existing infrastructure more efficiently. This would reduce the need for more investment and save ratepayers money.
Process
The Department of Public Utilities (DPU), along with the Department of Energy Resources (DOER) and the Massachusetts Clean Energy Center (MassCEC), held a stakeholder session in June 2025 with the goal of discussing key issues related to the use of grid-enhancing technologies and other advanced transmission solutions. The DPU also requested written comments from the Massachusetts electric and transmission companies, and industry stakeholders.
In September 2025, the DPU submitted its advanced transmission solutions report to the legislature.
In addition to the report, the DPU has a broader investigation into the use of advanced transmission solutions. Visit docket D.P.U. 25-69 to view all related filings and next steps in the proceeding.
Scope of the report
The DPU focused its investigation on emerging grid solutions identified by the legislature. For each technology, the DPU identified:
- key industry trends
- costs
- benefits
- implementation challenges
The DPU report provides a detailed analysis of the following 5 advanced transmission solutions:
- Dynamic line ratings (DLR) – technologies and methodologies that calculate real-time conductor thermal ratings to safely maximize line utilization.
- Advanced power flow control (APFC) – physical devices that adjust line impedance to manage power flows across the network. These devices can also relieve congestion.
- Topology optimization – software solutions that use algorithms to identify ways to reconfigure the grid. These solutions reroute power flows around congested areas;
- Advanced reconductoring – the process of replacing existing transmission lines with advanced conductors. These advanced conductors offer:
- greater efficiency
- higher current-carrying capacity
- lower sag
- Storage as a transmission asset (SATA) – using energy storage systems (such as batteries or pumped hydro) to inject or absorb power along a line. This solution mimics transmission line flows to solve congestion.
Report findings
The DPU found that to improve system performance and expand transmission capacity, advanced transmission solutions may offer:
- flexibility
- cost-effectiveness
- scalability
The following entities are studying their potential and developing use cases:
- transmission system owners
- technology providers
- policymakers
- regulators
However, these technologies are new. These technologies are also in varying stages of development. In the U.S. and in Massachusetts, deployments remain largely limited to pilot and demonstration projects. Future deployment of these technologies will depend on:
- further technological advancements
- changes to federal regulations
- changes to regional planning policies