A partially completed tower and a finished tower are seen in a section of the NECEC corridor along Route 201 in Bingham in December 2022. Gregory Rec/Staff Photographer

The developer of a controversial 145-mile electricity transmission line through western Maine has told state regulators it’s making progress after resuming work last October, but projects such as setting foundations for poles and running wires are only about one-third completed.

In a report Monday on the New England Clean Energy Connect, Avangrid, the parent company of Central Maine Power, told the Public Utilities Commission that access to the route is about 81% complete. However, 294 foundations for the setting of poles have been completed, or about 41% of the total; 217 poles have been set, 31% complete; and 36 circuit miles of wire work are done, or 34% of what’s required, Avangrid said.

The corridor, which is to bring hydropower from Canada to the New England electrical grid, has grown to $1.5 billion from an original price tag of $1 billion due to delays and cost inflation.

The project is organized under NECEC Transmission LLC, a subsidiary of Connecticut-based Avangrid Inc., the parent company of Central Maine Power. Both are controlled by Iberdrola, a Spanish multinational energy company.

The transmission line will connect 1,200 megawatts to the New England electrical grid.

The state Department of Environmental Protection halted work on the corridor in November 2021 after voters killed the project in a referendum. In court battles that followed, NECEC’s backers said the project had established “vested rights” to continue construction. A Cumberland County jury decided in April 2023 that the project may resume.

Advocates said the project would help reduce greenhouse gas emissions. Opponents were skeptical of the environmental benefits and said developers would gouge a path for the transmission line through some of Maine’s most pristine forested areas.

The project was initially planned in 2018 to begin with tree clearing in January 2020 and have power flowing at the end of 2022. Construction of the transmission line started in January 2021 with right-of-way clearing and access road preparation followed by installation of steel structures the following month, Avangrid said.

Avangrid told Maine regulators all contracts that were in place before construction stopped in November 2021 have been renegotiated.

Contracts for construction and materials for the high voltage direct current transmission line and network upgrades were awarded and executed, including contracts with construction and clearing companies with a “strong presence in Maine,” it said. NECEC is giving preference to hiring Maine workers, it said.

In addition, steel poles and most of the transmission materials, such as conductor, fiber and insulators, have been received, Avangrid said.

The report provided no information about when the project may be completed but indicated another report would be filed in January. Avangrid also did not say how much the delay may have cost developers, and said it would not comment on the report.

State Public Advocate William Harwood said Avangrid should be able to provide at least a timeline for completion. The project may no longer be in public view since the highly publicized legal battles ended, he said Wednesday.

Before construction halted, 139 miles of the high-voltage direct current right-of-way was cleared, Avangrid said. In addition, workers had installed 107 pole bases and 78 poles. The line is entirely cleared of trees and hundreds more pole bases and poles have been installed and 178 poles have had wires installed.

In Lewiston, construction of an electric converter station resumed in August 2023. Since construction resumed the remaining site preparation work has been completed and building foundations have been completed.