Grid Operators signal they are done with last Century's Technology and want something more dynamic, and it just happens to be or becoming cheaper...

"Historically utilities built “peakers,” usually gas turbines fueled by natural gas, to meet spikes in demand, but in recent solicitations Arizona Public Service chose battery storage projects over peakers. “This is a watershed moment that the utility is signaling,” says Manish Kumar, managing director for energy storage at AES Corp.

Late last month, APS, the largest utility in the state, said it plans to add 850 MW of energy storage by 2025, including 200 MW of stand-alone energy storage projects that competed and won against gas-fired peakers." https://www.enr.com/articles/46550-batteries-edge-out-natural-gas-peaking-plants-in-arizona-rfp