The Salt River Project Board of Directors on June 24 approved converting the existing coal-fired boilers at the Coronado Generating Station to run on natural gas.
Arizona public power utility SRP previously announced its intent to repurpose the CGS site and cease coal generation by the end of 2032. The natural gas conversion is planned for completion by late 2029.
The board's decision pursues the lowest-cost option to preserve the plant’s capacity that will be critical to meeting the peak energy demand of the Valley, which is expected to increase by 50% by 2035.
“SRP is exploring all options to meet future demand reliably, affordably and sustainably, including leveraging existing generating sites,” said Jim Pratt, SRP General Manager and Chief Executive Officer. “Converting the Coronado Generating Station to natural gas provides the best option to support our customers and the surrounding community.”
SRP considered the upfront investment and annual operating costs for potential replacement alternatives through 2045. Converting CGS to run on natural gas is expected to save SRP customers about $300 million compared to a new natural gas facility and about $1.2 billion relative to new long-duration lithium-ion batteries over the same period.
The decision also supports SRP’s carbon reduction goals and provides a bridge to the mid-2040s, when other generating technology options that could be used on the CGS site, including advanced nuclear, are mature.
Converting the CGS units to natural gas will require a new natural gas pipeline lateral to serve the CGS site and SRP will work to execute agreements for pipeline offtake.
SRP is also pursuing additional near-term resource technology options, including a long duration energy storage pilot, that can be deployed at the CGS site alongside the converted boilers.
“We look forward to continuing to be part of the St. Johns community and to continue our coal community transition efforts,” said Pratt.
SRP is working to at least 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 10,000 MW of renewables in addition to natural gas and storage resources.
SRP has nearly 3,000 MW of carbon-free energy – including more than 1,400 MW of solar – currently serving its customers.
SRP also has nearly 1,300 MW of battery and pumped hydro storage supporting its grid.
