Southwestern Transmission Line Project
Update - March 26, 2012
Record of Decision Obtained from US Forest Service
The Final Environmental Impact Statement and subsequent Record of Decision by the USFS for the project is complete and is available for download. The Final Biological Assessment is available for review as well. We invite you to review these documents.
Based on this action, the City anticipates receiving a Special Use Permit with the United States Forest Service to construct the Southwestern Transmission Line through the Apalachicola National Forest. Construction should begin in the latter half of this year.
Southwestern Transmission Line General Information
To ensure the ongoing reliability of the City of Tallahassee's electric system is maintained for the benefit of current and future customers, a new electric transmission line is being proposed for southwestern Leon County. The proposed line, known as the Southwestern Transmission Line (SWTL), is needed to meet national electric system reliability standards.
The City has been working to complete the initial phase of the permitting requirements to construct the transmission line through the Apalachicola National Forest (Proposed Route 1). This initial phase of permitting was in the form of a document known as an Environmental Impact Statement. The document assists the US Forest Service (USFS) in determining if the proposed route through the Apalachicola National Forest is the most beneficial route for all concerned parties. The report compares all three of the routes that have been described for the project and documents all of the potential environmental impacts this transmission line could have on these routes.
A separate document known as the "Biological Assessment" was also prepared in accordance with USFS regulations.
Purpose of the Southwestern Transmission Line
The North American Electric Reliability Corporation (NERC) is the electric reliability organization certified by the Federal Energy Regulatory Commission (FERC) to develop and enforce Reliability Standards for the bulk power system. NERC Transmission Planning Standards (TPL Standards 001-004) identify the mandatory planning standards that electric utilities must follow to ensure that reliable systems are developed that meet specified performance requirements.
The City conducts annual studies to evaluate the reliability of the bulk transmission system under a variety of contingencies that ensure the system meets the NERC standards. Recent studies have identified that the existing electric transmission network needs to be modified to ensure continued compliance with the NERC reliability planning standards.
Absent system improvements, the reliable delivery of power from the City's generating facilities and imported power via ties with other utilities to all customers cannot be ensured in the future under certain contingencies. The loss of multiple transmission lines due to a single event on a common right of way would cause other lines on the system to be overloaded. An additional electric transmission delivery path from east to west was identified as the means by which the City can maintain the ability to supply projected customer demands and wholesale transmission services into the future as required by the NERC Standards.
The proposed 230kV Transmission Line would provide enhanced system benefits that will meet the NERC mandated requirements and will improve system performance to the general public. These benefits include:
- Improved system reliability over a broader range of contingencies & longer duration as a result of providing an additional delivery path from generation sources and interconnections with other utilities to customers;
- Improved power transfer (east to west) as a result of the reduced losses associated with higher voltage transmission lines; and
- Address reliability concerns regarding the ability to supply future customer demands should one or more of the current east to west delivery paths become unavailable due to an equipment fault or failure.