Benton and Clinton, ME

Substation and Transmission Design for Solar Integration in Maine

Client: Central Maine Power Company
Our Role: Electrical and Structural Engineering for Substation Physical, Protection and Control, and Transmission Line Design

High-voltage substation equipment with steel structures, insulators, and transmission lines supporting solar energy interconnection to the power grid.

Central Maine Power needed to interconnect a new solar generation facility to its transmission system while maintaining reliability at the Albion Road 115 kV substation. The project required modifications to existing infrastructure, installation of new protection and metering equipment, and coordination with existing transmission lines to support safe and reliable integration of renewable energy into the grid.

The interconnection design needed to accommodate new line terminations, maintain system protection and communication functionality, and support future operational reliability for the transmission network.

GFT provided engineering services for the detailed design of the Three Corners Solar interconnection to the Albion Road 115 kV substation, including a breaker bay addition and transmission line revisions. The team developed design solutions to support the new termination of Line S257 and modifications to the existing Line S294 bay while maintaining system protection and communication functionality.

The design included removal of the existing 115 kV straight bus, installation of new substation equipment, and development of foundations and structural supports for the new 115 kV bay. The project also incorporated protection system upgrades, installation of revenue metering infrastructure, and reconnection of optical ground wire (OPGW) systems to maintain communications and system reliability.

GFT prepared detailed design packages for the In-Ground, Above Ground, SPC-1, and SPC-2 design phases to support construction and system integration.

Key Features

Detailed design for solar interconnection to a 115 kV transmission system.
Breaker bay addition at the Albion Road substation.
Removal and replacement of existing 115 kV straight bus infrastructure.
Installation of a new 115 kV circuit breaker and associated equipment.
Design of foundations and structural supports for new substation equipment.
Installation of revenue metering infrastructure for transmission operations.
Reconnection of OPGW communication systems.
Protection system upgrades, including adaptation of Generic Object Oriented Substation Events (GOOSE) messaging.

Outcomes

Enabled reliable integration of new solar generation into the transmission network.
Maintained system protection, communications, and operational reliability.
Improved infrastructure capacity to support renewable energy development.
Delivered construction-ready design packages to support efficient project execution.