Texas-based public power, natural gas and electric company CPS Energy has signed an agreement to purchase an additional 2% stake in the South Texas Nuclear Project (STP) from Constellation.

This transaction will increase CPS Energy's ownership in STP to 42%.

CPS Energy also signed a long-term power purchase agreement (PPA) with Constellation for an additional 200MW of firm capacity.

This capacity will be available to customers of CPS Energy for summer (June to August) 2024.

Constellation's stake in STP will adjust to 42%, while Austin Energy will maintain its 16% share.

The additional 2% ownership for CPS Energy translates to an increase of 52MW in carbon-free dispatchable generation to its portfolio, whilst aiding in the company's Vision 2027 strategy.

Vision 2027 anticipates the retirement of 2.25GW of ageing generation capacity by the end of the 2020s.

CPS Energy president and CEO Rudy D Garza said: “The addition of these megawatts to our system supports reliability for our customers as we enter another summer season.

“CPS Energy continues to stay focused on our Vision 2027 plan and will continue our focus on reliability for our growing community.”

CPS Energy added 1.7GW of natural gas, 730MW of solar energy and 50MW of energy storage under its generation plan to date, with a further 500MW energy storage RFP [requests for proposals] in the pipeline. 

CPS Energy recently completed the acquisition of three natural gas plants in Texas from Talen Energy for $785m.

The deal adds 1.7GW and comprises the 897MW Barney Davis and the 635MW Nueces Bay natural gas-fired generation facilities in Corpus Christi, and a 178MW facility in Laredo.