April 22, 2026 Maine Substation Construction and Upgrades Support New DC Transmission Line
E.S. Boulos builds new DC switchyards, upgrades multiple substations to enable power to flow from the New England Clean Energy Connect
When the New England Clean Energy Connect (NECEC) began delivering clean hydropower from Canada to New England in January 2026, it marked a leap forward for the region’s clean energy future. Before that could happen several substations across Maine needed to be upgraded and two new substations had to be built in some of the state’s most remote terrain.
E.S. Boulos (ESB), an MYR Group subsidiary, was the electrical contractor selected for this critical infrastructure project in Northwest Maine. ESB’s utility and commercial divisions were both involved in supporting power from NECEC for different customers. Their utility teams provided upgrades at four 345kV alternating current (AC) substations, remote end work at two others, and constructed two greenfield direct current (DC) substations. ESB also provided electrical equipment upgrades to connect a STATCOM (static synchronous compensator) to the power grid.
One of ESB’s commercial teams added essential support by performing power and lighting work at the Lewiston converter station where NECEC’s power transitions from DC to AC.
Completed between late 2023 and late 2025, these projects were highly successful. ESB finished all substation work on time and maintained an impeccable safety record, with nearly 62,000 combined work hours, including subcontractor contributions, without any recordable or lost time incidents. The STATCOM project took 16,461 work hours and was also completed without recordable or lost time incidents.
Constructing DC Switching Stations in Rural Maine
Although capable of carrying power over long distances with less power loss, DC transmission lines are extremely rare in the U.S. compared to AC transmission lines.
To support this new DC transmission line and the power coming into New England, a private developer needed two identical DC switching stations constructed on either side of the Kennebeck River. The line went under the river due to the popularity of river rafting in this remote, mountainous area of Maine.
ESB was responsible for constructing the new switching stations and a small station for monitoring the power lines. Their scope of work included removing the topsoil, completing the excavation and site work construction, overseeing the foundation installations, and installing and grounding all the structural steel and components for the switching stations where it would connect to underground cabling on both sides of the river.
The remote locations of the DC substations introduced challenges, especially during the winter and spring when dirt roads turn muddy. One of these new stations was eight miles from the nearest paved road, while the other was roughly six miles away. This required thoughtful planning by the project team to manage communication and logistics.
The substations were designed with large blast walls made of precast concrete to protect against outages caused by accidents or vandalism. In recent years, utilities in other regions of the country have dealt with vandalism-driven outages causing more companies to strengthen the security of their electrical systems, including substations and switchyards.
Delivering materials for the blast walls involved careful planning and complex logistics. Because each site could only be reached by narrow dirt roads similar to the size of an ATV trail, and the remote station sites had little room to turn around after unloading the materials, the 52-foot trucks were staged offsite. In total, roughly 75 truckloads of pre-cast concrete were needed for the two sites, and about eight trucks a day could make deliveries.
The remote locations also meant lodging ESB’s crews in hunting or sporting lodges, due to the lack of hotels in the area.
ESB’s upgrades to several existing utility-owned 345kV AC substations receiving power from the NECEC transmission line varied in scope. Across the locations, the combined work included adding a new bay, adding 345kV terminals, about 120 foundations, breakers, line switches and controls, CCTVs, and remote end/relay work.
“As a company, we have a long history of serving the region’s power needs and were proud to execute the substation work which was integral to bringing the new NECEC transmission line in-service on time,” ESB District Manager Adam Mancini said.
ESB Also Supports DC to AC Conversion Upgrades for Commercial Customer
ESB offers customers in the northeastern U.S. a range of electrical construction services including commercial and industrial (inside electrical construction) and utility services like substations and switchyards.
By having both types of capabilities, ESB was able to support NECEC’s delivery of clean energy to New England with multiple projects, including the substation construction and upgrades needed at the converter station.
The power from the NECEC DC line is converted to AC power at a converter station in Lewiston, Maine. ESB’s commercial division made upgrades at that station, working with a customer to install all power panels, cable tray, low voltage pathways, ground bar, wire, lighting, fire alarm, security and IT networks.
They worked closely with management and engineering teams to offer practical solutions as issues arose. This included working with the customer’s design team to modify the cable tray. ESB’s team also supported another contractor with cable pulling at the converter station.
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