CenterPoint Energy (NYSE:CNP) on April 3 said that its electric utility has submitted a proposal to ERCOT requesting its endorsement for the company to enhance existing – and build new – electric transmission infrastructure.
The project includes enhancements to two existing substations and construction of a new 345-kV double-circuit transmission line, the company said, noting that it expects to have the proposed enhancements complete by summer 2019, while the proposed line is anticipated to be in service in 2021.
The project would meet the unprecedented load growth of the petrochemical industry in the Freeport, Texas, area, the company said, adding that that growth includes new committed load expected to total about 1,340 MW, which is planned to go into service at varying stages between 2017 and 2019.
According to the March 30 “Freeport Area Master Plan Project” filing, the Freeport Area is located in the southernmost part of the service territory of CenterPoint Energy Houston Electric adjacent to the Gulf of Mexico; has a major seaport; and is a highly industrialized area with several large chemical facilities served by the CenterPoint Energy transmission system.
CenterPoint Energy said that it completed projects in 2016 and early 2017 – the Freeport Area Upgrades and the Dow-Velasco 345/138-kV Autotransformer Addition – and is completing a project this year – the Jones Creek Project – to increase the load-carrying capacity of the transmission system in the Freeport Area.
However, the company said, as the load continues to grow in that area, and the potential for additional transmission system capacity upgrades becomes limited, the need for long-term transmission line capacity alternatives increases.
The company also noted that ERCOT has shown voltage and loading concerns in the Freeport Area as early as 2018/2019 through 2022 in the 2016 Regional Transmission Plan and in the 2016 Long Term System Assessment.
Additionally, the company said that it has completed a reliability evaluation of the need for additional transmission line capacity alternatives in the Freeport Area. That study identified potential reliability concerns starting in 2019 with respect to NERC Reliability Standard TPL-001-4, ERCOT Transmission Planning Criteria, and Centerpoint Energy Transmission System Design Criteria, the company said.
CenterPoint Energy said that it has signed letter agreements with customers in the Freeport Area totaling about 1,340 MW of new load expected to be connected to the system between 2017 and 2019, and has received additional inquiries for another proposed 550 MW of load additions in the area by 2021. With the 1,340 MW of new committed load by 2019, power flow studies show overloading of the existing 345-kV circuits as well as severe low voltages in the area, the company said.
CenterPoint Energy said that it studied eight options, and selected “Option 5,” or the approximately $247m Freeport Area Master Plan Project, which consists of the “Bridge the Gap Upgrades,” to be completed before peak 2019, and the new 345-kV transmission line, to be completed before peak 2021.
The “Bridge the Gap Upgrades” involve the:
- Loop 345-kV South Texas Project (STP) – Dow-Velasco circuit 27 into the Jones Creek substation (about 0.9 mile)
- Installation of 7-ohm in-line reactors at the Jones Creek substation on 345-kV STP – Jones Creek circuits 18 and 27
- Installation of the 3rd 345/138-kV 800/1,000 MVA Autotransformer at the Jones Creek substation
- Installation of the 4th 138-kV Capacitor Bank (120 MVAr) at the Jones Creek substation
- Installation of the 1st 138-kV Automatically Switchable Capacitor Bank (140 MVAr) at the Jones Creek substation
- Installation of the 2nd 138-kV Automatically Switchable Capacitor Bank (140 MVAr) at the Jones Creek substation
The company also said that it would build the new approximately 48-mile, 345-kV double-circuit line from the Bailey substation to the Jones Creek substation, and upgrade the 345-kV Dow-Velasco – Jones Creek circuits 18 and 27 to at least a 1,700 MVA emergency rating.
In its April 3 statement, the company said that the proposed project timeline takes into consideration the typical lead times necessary to implement the proposed enhancements and construction, including review by ERCOT and the Public Utility Commission of Texas. The company said that it anticipates a decision by 4Q17.