American Electric Power’s (NYSE:AEP) Southwestern Electric Power Company (SWEPCO) on July 31 filed with the Public Utility Commission (PUC) of Texas a petition seeking certificate of convenience and necessity (CCN) authorization to acquire an interest in the Wind Catcher Energy Connection Project to be located in Oklahoma.
The wind facility will be located on more than 300,000 acres in Texas and Cimarron counties in the Oklahoma Panhandle under lease to Invenergy for wind energy development, the company said.
With an increasing penetration of wind in the Southwest Power Pool (SPP) and the expectation for additional congestion in the region, SWEPCO and its affiliate Public Service Company of Oklahoma (PSO) (together referred to as the companies) undertook a process to evaluate the possibility of directly interconnecting that wind resource to load, thereby reducing congestion risk, SWEPCO said.
American Electric Power Service Corporation’s (AEPSC) team of engineers and construction professionals, in coordination with Quanta Services, developed the Wind Catcher Generation Tie Line (Gen-Tie) as a feasible and cost-effective interconnection solution, SWEPCO noted.
Accordingly, SWEPCO said that the project, which is proposed to be owned 70% by SWEPCO and 30% by PSO, includes two key components:
- The wind facility – which includes 800 General Electric model 2.5-MW wind turbine generators – that would provide 1,900 MW of delivered (2,000 MW nameplate) wind energy, with an expected net capacity factor of about 51%. Invenergy started construction in 2016, and has targeted completion in 3Q20 to meet safe harbor eligibility requirements for 100% of the PTC available for the wind facility
- The Gen-Tie, which will be an extra-high voltage (EHV) 765-kV line running about 350 miles to 380 miles through northern Oklahoma from the wind facility site in the Panhandle east and slightly south to the AEP load zone in the Tulsa area. The companies have contracted with Quanta Services to build the Gen-Tie
SWEPCO said that the companies have entered into a Membership Interests Purchase Agreement (MIPA) with Invenergy to purchase the wind facility, subject to regulatory approvals and other conditions. The companies will purchase the wind facility at its commercial operation date – estimated 3Q20, SWEPCO said.
In order to acquire the wind facility in a manner that preserves the value of the federal PTC for its customers, the MIPA is structured such that the companies will acquire 100% of the equity in States Edge Wind I LLC – the entity created specifically to own all of the rights and assets with respect to the wind facility – and, along with it, the wind facility, SWEPCO said. The companies will acquire States Edge Wind I LLC from States Edge Wind I Holdings LLC, a wholly owned subsidiary of Invenergy, SWEPCO noted.
The total estimated cost – including Allowance for Funds Used During Construction (AFUDC) of the wind facility is about $2.9bn, of which the SWEPCO share is about $2bn. SWEPCO added that the total estimated cost – including AFUDC – of the Gen-Tie is $1.6bn, of which the SWEPCO share is about $1.1bn. Accordingly, SWEPCO noted that its total estimated cost of the project – including AFUDC – is about $3.2bn. The company added that the SWEPCO Texas retail jurisdictional total estimated cost of the project – including AFUDC – is $1.1bn.
SWEPCO said that it seeks CCN authorization by April 30, 2018, so that the wind facility will be in service by Dec. 31, 2020, in order to take full advantage of the federal PTC.
According to the direct testimony for SWEPCO of Robert Bradish, vice president – Grid Development for AEPSC, the Gen-Tie – which consists of three-phase lattice tower structures on 200-foot-wide rights of way – will interconnect wind-generated power via a radial, single-circuit, 765-kV generation tie line from the wind facility into the existing transmission system at the existing PSO Tulsa North 345-kV substation.
The Gen-Tie consists of the proposed 345-kV to 765-kV generation substation, referred to as the Western 765-kV Generation Substation, the proposed 350-mile to 380-mile, 765-kV line, and the proposed 765-kV to 345-kV substation, referred to as the Tulsa North 765-kV Generation Substation.
Bradish added that the Gen-Tie has a projected completion date in 2020, and that it will be built via fixed-price Engineer, Procure, Construct (EPC) contractual agreement with a subsidiary of Quanta Services.
The Western 765-kV Generation Substation, located near the wind facility at the western endpoint of the Gen-Tie line, will serve as the aggregation point for the collector substations from the wind facility, Bradish said. The 765-kV Gen-Tie line interconnects at the Western 765-kV Generation Substation and traverses about 350 miles to 380 miles across Oklahoma to interconnect at the proposed Tulsa North 765-kV Generation Substation at the eastern endpoint of the Gen-Tie line, located near PSO’s existing Tulsa North 345-kV substation. The proposed Tulsa North 765-kV Generation Substation will transform the wind power from 765 kV to 345 kV for interconnection to the existing PSO Tulsa North 345-kV substation, Bradish added.
Among other things, Bradish said that the Western 765-kV Generation Substation will be built as a 765/345-kV station with three single-phase 765/345-kV, 750MVA autotransformers with a single-phase switchable spare, three sets of 765-kV 300 MVAR shunt reactor banks with two single-phase switchable shunt reactor spares, a four-rung 345-kV breaker and a half station layout with six line positions and one future line position, and three sets of 100 MVAR capacitor banks on each of the two main buses.
The Tulsa North 765-kV Generation Substation – which will include the installation of six 345-kV 50 MVAR capacitor banks – will be built as a 765/345-kV station with three single-phase 765/345-kV 750 MVA autotransformers with a single-phase switchable spare, and three sets of 765-kV 300 MVAR shunt reactor banks with one single-phase switchable shunt reactor spare, Bradish said.