Georgia Interconnection Project
In 2012, Vermont Electric Power Company (VELCO) and Green Mountain Power (GMP) proposed upgrades to the transmission and sub-transmission network in northwest Vermont including a transmission line to interconnect VELCO's Georgia substation to a new GMP switching station in Georgia, Vermont, an installation of an additional transformer at VELCO's Georgia substation, and a capacitor bank at VELCO's East Fairfax substation to improve the reliability of electric facilities serving St. Albans and areas to the east.
Needs & Benefits
The Georgia substation interconnects VELCO's electric transmission network in northwest Vermont and feeds the electric distribution system serving GMP and Vermont Electric Cooperative (VEC) customers. Failures of key transmission components could cause low-voltage conditions that violate system standards, voltage instability/collapse or thermal overloads, which could result in extended outages for the area served by the transmission system.
Transmission utilities such as VELCO are required to design, operate and maintain a transmission network according to national and regional reliability standards. Planning studies by VELCO, GMP and ISO New England, New England's bulk electric system operator, reveal that the existing infrastructure in northwest Vermont does not meet current federal and local area reliability requirements. Specifically, the loss of a single transmission element would result in a voltage collapse event and loss of load at or near present peak load levels.
As outlined in VELCO's 2006 and 2009 Long-Range Transmission Plans, the vulnerability of the current transmission and sub-transmission network interconnection results in system reliability problems, which under certain circumstances may lead to loss of service, system outages, and low voltage. These concerns can be addressed by installing a transformer at the Georgia substation and a capacitor bank at the East Fairfax substation, along with GMP's proposed system reinforcements.
The project consists of a combination of transmission and sub-transmission upgrades including the following:
- Install new transformer and associated protection equipment (Georgia substation)
- Install new capacitor bank (East Fairfax substation)
- Build new distribution switching station
- Construct 2-mile sub-transmission line
- Replace 4.5 miles of conductor wires and certain poles on existing sub-transmission line
All proposed work at the VELCO Georgia substation site will occur within areas of previous disturbance and within the substation fence.
The East Fairfax substation site will require minimal tree clearing, expansion of the fence and addition of gravel substation yard material to accommodate the installation of a new capacitor bank. This work will be limited in nature and will not impact any regulated resources. In addition, all VELCO-related work will be performed in accordance with the VELCO Environmental Guidance Manual (VEGM).
VELCO's noise consultant assessed the potential noise impacts associated with the transformer and capacitor bank installation. A complete engineering noise analysis was provided as part of the Project's filing with the Public Service Board and was found to not present an adverse impact in the project area.
- Winter 2013-2014
- Public meetings
- Regulatory and permitting process
- Fall 2014
- Construction start
- Spring/Fall 2015
- Construction complete