Vermont Electric Power Company proposes to upgrade the Berlin Substation. The upgrade is needed because a recent conditions assessment revealed deficiencies within the substation. The transmission system upgrade will improve reliability of electric facilities serving portions of central Vermont.
Needs & Benefits
The original Berlin Substation was built in 1982, with various modification and improvements occurring over the nearly thirty-seven years of service. VELCO conducted a conditions assessment of the Substation and identified the need to replace some of the equipment due to condition. Deficiencies were identified in equipment such as the protection and controls, 115 kV breakers, 34.5 kV breakers, switches, fence and control building.
VELCO proposes to address the majority of the Substation concerns by upgrading the protection and control system and constructing a larger control building. Other elements of the Substation will be addressed by in-kind replacement and modifications of the existing equipment. Redundancy improvements of the alternating current (AC) and direct current (DC) station services will also occur. This work will require VELCO to expand the fence by approximately 15 feet on the substation’s west side, approximately 25 feet on the east side, and approximately 42 feet on the southeast side to accommodate the new control building.
The proposed improvements to the Substation will require the installation of a temporary 115/34.5 kV substation in order to maintain service to the Green Mountain Power (GMP) sub-transmission system. VELCO proposes to utilize the Barre Temporary Substation in support of the Berlin Project.
- Replace the protection and control system with a system that provides diversity, redundancy and communication aided schemes.
- Install nine new 115 kV instrument voltage transformers in support of the new protection and control system.
- Replace the existing VELCO control building with a new control building that is able to accommodate the new protection and control system, redundant AC & DC station services, communication equipment and security systems. The new control building will be located on the southeast side of the Substation which will better facilitate the construction activities and future access.
- Replace the existing 115 kV circuit switcher with a 115 kV breaker and disconnect that meets VELCO’s design standards.
- Replace all three of the existing 115 kV breakers with new 115 kV breakers.
- Install a passive secondary oil containment system for the 115/34.5 kV power transformer.
- Expand the fence to accommodate the new control building, facilitate construction, and to improve access to equipment for maintenance.
- Work with GMP to replace or relocate some of the existing 34.5 kV poles, so the poles are outside the fence.
- Replace an existing three pole 115 kV line structure with a single pole 115 kV structure to facilitate changes to the phasing of the K55 Line.
VELCO’s aesthetic consultant (T.J. Boyle Associates) review the preliminary design plans and performed a visual analysis of the areas of the proposed Project. The findings indicate the Project will not create any adverse aesthetic impacts. The area near the Berlin Substation includes a variety of industrial and utility uses, including a solar generation facility, substation and gas fired generator, railroad tracks, and the existing VELCO substation and transmission lines. Existing vegetation and landform screen most visibility from the surrounding area. However, improvements will require vegetation clearing, including removal of mature evergreen trees southeast of the Substation. T.J. Boyle Associates recommends new evergreen landscape mitigation to further improve the screening of the Substation. A full analysis of potential aesthetic impacts and proposed landscaping to mitigate those impacts will be included with the Petition filed with the Public Utility Commission. VELCO does not anticipate adverse aesthetic impacts from the project.
VELCO’s noise consultant, Resource Systems Group, Inc. (RSG) will assess the potential noise impacts associated with the Project. A complete engineering noise analysis will be provided as part of the Project’s filing with the Public Utility Commission. Preliminary findings from RSG indicate no adverse impacts are expected at the residence closest to the substation.
- Spring 2019
- Public meetings
- Summer 2019
- Regulatory and permitting process
- Spring 2020
- Construction start
- Winter 2020
- Anticipated completion