Sharyland Utilities Proposes Panhandle Transmission Expansion: the South Plains Transmission Project

10.31.16

Sharyland has actively monitored the development and financial commitment of generation resources in the Panhandle region over the past year and, given the significant increase in wind generation resources since the last ERCOT independent assessment in the region, has prepared a comprehensive Panhandle region transmission assessment. 

Based on that assessment, on September 20, 2016, Sharyland presented nine transmission expansion options with the objective of increasing the Panhandle export limit. A report summarizing those options was provided, and Sharyland recommends Option #3 (South Plains Transmission Project or “Project”) as the preferred option to address the future needs of the Panhandle region. 

The Project builds on other recent decisions concerning Panhandle transmission capacity. Based on the 2015 recommendation of the ERCOT independent assessment of the Panhandle region, at its September 24, 2015 Open Meeting the Public Utility Commission of Texas (PUCT) recommended the construction of the second 345 kV circuit on the Alibates – AJ Swope – Windmill – Ogallala – Tule Canyon (AAWOT) line under the CREZ Order (PURA §39.904(g)) and in the summer of 2016 approved a Certificate of Convenience and Necessity (CCN) for that project. Additionally, on December 8, 2015, the ERCOT Board of Directors approved the addition of two synchronous condensers, one each at Sharyland’s 345 kV Alibates and Tule Canyon stations. The tender for the synchronous condenser has been awarded and the condensers, along with the construction of the AAWOT line, are on schedule to be completed by June of 2018. The estimated Panhandle export transfer capability with these project additions is 4,013 MW.

ERCOT’s recommendations for the addition of the second circuit and the synchronous condensers were economically justified per the ERCOT economic planning criteria. These recommendations were based on ERCOT’s independent assessment of the Panhandle region needs performed in September 2015, when the Panhandle Wind Generation Resources (WGR) capacity meeting Section 6.9 requirements of the ERCOT Planning Guide was approximately 4,305 MW. During the course of the last year, there has been a significant increase in the Panhandle capacity meeting Section 6.9 requirements, with a new total of WGR capacity of approximately 5,269 MW. 

This Sharyland assessment of the Panhandle region spans system strength, power flow, dynamic stability, and production cost based economic assessments. Numerous transmission expansion options were investigated in the Sharyland studies with the objective of expanding the Panhandle export limit to accommodate the increases in generation capacity. At the August and September, 2016 ERCOT RPG meetings, Sharyland presented updates of the wind generation interconnection activity in the region, along with a study scope to review the addition of additional shunt reactive devices and new transmission paths to increase the Panhandle export transfer capability. Comments on the scope of work and transmission options were incorporated in the study plan.

Sharyland recommends the South Plains Transmission Project as the preferred option to address the future needs of the Panhandle region. The Project includes the following three transmission additions: 

· New 67.5 mile 345 kV (double circuit capable) Abernathy – Grassland single circuit line 

· New 53.2 mile 345 kV (double circuit capable) Ogallala – Abernathy single circuit line 

· One (1) 175 MVA synchronous condenser at Windmill (minimum short circuit contribution of 1606 A at the condenser terminals) 

The South Plains Transmission Project provides the highest Panhandle export capability amongst all the options evaluated by Sharyland when taking both system strength and dynamic performance into account. 

 The capital cost estimate for the South Plains Transmission Project is estimated to be $251 Million. Assuming ERCOT endorsement by Q2, 2017, Sharyland estimates the project to be in service by the end of 2020. With the addition of the Project, the estimated Panhandle export transfer capability increases from 4,013 MW to 4,833 MW.

Comments of support are due by Monday, November 7 to ERCOT

South Plains Transmission Project Comment Form .DOC

South Plains Transmission Report PDF

ERCOT Summer Wind PDF