American Electric Power’s (NYSE:AEP) AEP Ohio Transmission Company (AEP Ohio Transco) on Jan. 19 filed with the Ohio Power Siting Board (OPSB) an application for a certificate of environmental compatibility and public need for the approximately 3.3-mile Herlan-Blue Racer 138-kV Transmission Line Project in Monroe County, Ohio.
The proposed project, which would resolve thermal overload and low voltage violations identified on the AEP system, is part of a larger program of improvements to the existing transmission service network in eastern Ohio.
AEP Ohio Transco, in conjunction with PJM Interconnection, in 2015 identified multiple thermal-overload and low-voltage violations on the company’s system in Noble and Monroe counties in Ohio. The company added that those violations occurred on both the AEP Ohio Transco bulk electric system (100 kV and higher), as well as the local sub-transmission system, and were attributed to the above-average load growth in the region. The increased load growth in the area is attributed to the Utica Shale industry, as well as associated industrial customers, the company said.
To resolve the identified reliability risk and to provide the area with additional electricity sources, AEP Ohio Transco said that it is proposing to build the project, in conjunction with the construction of the new Herlan 138-kV switching station, which is the subject of OPSB Case No. 16-1856-EL-BLN.
PJM reviewed several competing proposals to resolve the reliability risks in the area and ultimately approved the proposed project along with the Herlan switching station as the optimal system upgrade – the combination project is identified as “Baseline RTEP upgrade #b2701.”
The company also said that the proposed project would increase system reliability in the area by:
- Improving switching flexibility, operational performance, system protection schemes, and balance circuit flows by connecting the Muskingum-Natrium 138-kV double-circuit transmission line to the new switching station
- Improving voltage performance in the area by installing two 138-kV capacitor banks at the Herlan switching station and tying the 138-kV circuits together at Herlan
- Serving as a central hub for AEP Ohio Transco’s area 138-kV transmission system and providing the flexibility to handle future load growth, while ensuring adherence to NERC transmission planning standards. The proposed project would provide a new energy source to large industrial customers in the Summerfield area, which are served by an aging radial 138-kV line
The company said that the preferred route is located entirely within Monroe County in southeast Ohio, and would traverse portions of Franklin and Seneca townships. The company noted that the project’s general vicinity is characterized as primarily forested with steep, V-shaped valleys and narrow ridgetops.
The preferred route would be about 3.3 miles long, built as a single-circuit 138-kV line that requires a 100-foot-wide right of way (ROW), and consist of two-pole galvanized H-frame structures with an anticipated height to range between about 70 feet and 90 feet above ground.
The company added that the preferred route (also referred to as “Alternative Route A”) would exit the Herlan switching station to the southwest through agricultural and forested land for a short distance before crossing State Route 78. After crossing Route 78, the route turns slightly to the southeast and parallels Route 78 for about 0.7 mile, primarily through forested land. The company also noted that the route then crosses Route 78 twice through forested and agricultural areas to avoid constraints to the east. South of Route 78, the route turns southeast and parallels the Summerfield-Berne 138-kV Transmission Line for about 1.3 miles through forested land and adjacent to the Christman Quarry and natural gas infrastructure before terminating at the Blue Racer substation.
The route would require about 39.9 acres of new ROW, the company said.
Alternative Route A was selected as the preferred route primarily because it minimizes impacts to the built and nature environment by paralleling Route 78 and the Summerfield-Natrium 138-kV Transmission Line for more than 75% of its route. The company added that paralleling existing infrastructure would result in fewer changes to the existing landscape and land use, slightly fewer acres of tree clearing, and would provide opportunities to use existing access roads associated with the Summerfield-Natrium line.
Pending approval from the OPSB, AEP Ohio Transco said that it plans to begin construction in fall 2018, to meet a June 1, 2020 in-service date.