The Arizona Power Plant and Transmission Line Siting Committee, in a Dec. 11 notice, said that a public hearing will begin on Jan. 17 – and continue on Jan. 18 – in Tucson, Ariz., regarding Tucson Electric Power’s (TEP) application for certificates of environmental compatibility authorizing the construction of the Reciprocating Internal Combustion Engine (RICE) Generation Project and the Irvington 138-kV Transmission Line Relocation Project.
According to TEP’s application, filed on Dec. 8, the transmission line project will consist of new and modified 138-kV transmission lines totaling about 2.6 miles to connect the RICE Generation Project to TEP’s transmission system, and enable the construction of a new 138-kV substation, which is replacing an existing substation.
The application further noted that the transmission line project entails the construction of 2.2 miles of new 138-kV transmission lines, which requires about 24 new 138-kV transmission structures that will be a mixture of tangents, double deadend angle, and deadend steel poles. An additional 0.4 miles of existing 138-kV transmission line will be repurposed, the application added.
The purpose of the transmission line project is to support the new Irvington 138-kV substation, which will replace the existing, aged main and transfer and ring bus configuration with a new breaker and a half configuration, thereby providing improved reliability for TEP’s system, the application said.
The “estimated costs of proposed transmission line and route” is about $850,000 per mile, the application noted.
According to the notice, the RICE Generation Project involves a new natural gas-fired, RICE generation plant located on the Irvington Campus at South Contractors Way and East Irvington Road in Tucson. The RICE Generation Project is composed of 10 natural gas-powered units capable of producing about 20 MW each, for a build-out total of 200 MW, the notice said, adding that RICEs are part of TEP’s long-term resource plan and were identified in its Integrated Resource Plan filed with the Arizona Corporation Commission (ACC) in April.
According to TEP’s application, the 10 stacks, in clusters of five, will be about 160 feet tall. The first five units – about 100 MW – are scheduled to be in operation by June 1, 2019, while the balance of the units will be in operation within 1Q20. The application added that the planned construction start date is April 2, 2018, and that the RICE Generation Project is currently estimated to cost about $180m for all 200 MW of capacity.
The application noted, “The RICE will provide necessary fast-ramping, thermal resources and replace aging steam generation units (Sundt Units 1 and 2) in furtherance of TEP’s goal of reaching 30% renewables by 2030.”
According to the application, for the last 50 years, TEP has relied on coal plants to meet the majority of its customers’ energy needs. Currently, resource economics and environmental considerations have shifted the historically strong preference for coal to a more balanced use of coal, natural gas, and renewable resources, the application noted.
To meet changing customer use patterns and more stringent operating requirements, TEP has developed a long-term portfolio diversification strategy, in which TEP is reducing its reliance on coal. Among other things, the application added that by mid-2022, TEP will reduce its coal-fired capacity by 508 MW through planned retirements, resulting in significant cost savings for customers, as well as meaningful reductions in air emissions and water consumption.