Upgraded CMP Substation Boosts Reliability for Nearly 10,000 Customers
The new substation switch strengthens the grid and shortens outage times for the Portland area as part of CMP’s broader grid modernization efforts
AUGUSTA, ME – October 31, 2025 – Central Maine Power (CMP), a subsidiary of Avangrid, today announced the completion of a major upgrade at its Cape Substation in South Portland, part of the company’s broader initiatives to build a stronger, smarter, and more resilient electric grid across its service area.
As part of this project, CMP crews installed a nearly three-ton switch, replacing a 70-year-old unit that had reached the end of its decades-long service life. The new switch can incorporate advanced technology, is better protected against extreme weather, and is designed to operate more safely and efficiently. This upgrade will improve service for more than 9,000 customers in the Portland area by reducing outage durations and enhancing overall system reliability.
“This upgrade marks a major step forward in strengthening the grid for our customers. By replacing a 70-year-old switch with a modern, stronger unit, we’re not only enhancing reliability and safety, but we’re also making the system easier to maintain and faster to operate,” said Eric Sutton, Vice President of Electric Operations for Central Maine Power. “This complete upgrade will help shorten outage times, improve resilience against extreme weather, and ensure our customers benefit from smarter, stronger, and more secure energy infrastructure.”
Substation switches are essential components that control the flow of electricity by allowing operators to connect or disconnect parts of the electrical network, move power between lines, and isolate equipment for safe maintenance and repairs. They also help isolate sections of the energy grid during power interruptions. The new switch at the Cape Substation strengthens CMP’s ability to manage power efficiently and respond quickly to service disruptions.
The Cape Substation, like other transmission lines and substations in and around Greater Portland, plays an important role feeding large numbers of customers in and beyond this region. Upgrades to aging equipment in this area are designed to support the region’s growth, as well as the businesses, healthcare facilities and centers of education that serve Mainers across the state.
Crews completed the installation of this new switch in mid-October without any interruptions to customers’ electric service.