The Salt River Project Board of Directors on Nov. 3 approved converting the SRP-owned coal-fired Springerville Generating Station (SGS) Unit 4 to run on natural gas.
The decision is the lowest-cost option to preserve the plant’s 400-megawatt (MW) generating capacity, enough to serve 90,000 homes, which is important to meeting the Valley’s growing power need in the early 2030s, the Arizona public power utility said.
“Converting Springerville Generating Station Unit 4 to run on natural gas allows us to continue to use this important asset to meet increasing energy demand,” said Jim Pratt, SRP General Manager and Chief Executive Officer. “This decision demonstrates our commitment to finding the least cost option to serve our customers with reliable power.”
SRP reviewed the upfront investment and annual operating costs for potential replacement alternatives through 2049. Converting SGS Unit 4 to run on natural gas is expected to save SRP customers about $45 million compared to building a new natural gas facility and about $826 million relative to adding new long-duration lithium-ion batteries over the same period.
The decision also provides a bridge to the mid-2040s, when other generating technology options, including advanced nuclear, are mature.
The converted SGS Unit 4 will be served by the new natural gas pipeline lateral that is also needed to serve the Coronado Generating Station (CGS) site. SRP will work to execute agreements for pipeline offtake. The SRP Board of Directors recently approved converting the coal-fired boilers at CGS to natural gas.
SRP is working to more than double the capacity of its power system in the next 10 years while maintaining reliability and affordability and making continued progress toward our sustainability goals. SRP will accomplish this through an all of the above approach that plans to add renewables in addition to natural gas and storage resources, it said.
SRP has nearly 3,000 MW of carbon-free energy – including more than 1,500 MW of solar – currently serving its customers. SRP also has nearly 1,300 MW of battery and pumped hydro storage supporting its grid.
SGS is operated by Tucson Electric Power (TEP), which owns Units 1 and 2. TEP announced its plans to convert Units 1 and 2 to natural gas earlier this year. Tri-State Generating and Transmission owns SGS Unit 3.
