A unit of General Electric Corp. (GE) plans to close a one-of-its-kind natural gas-fired baseload generation plant in Southern California using turbine technology that has never taken hold commercially.

Industry observers viewed the decision to shut the 10-year-old Inland Empire Energy Center as strictly a function of economics, as the baseload market for which the plant was constructed evolved into a renewables-driven market for fast-start peaking gas-fired generation.

The poor economics for the facility in Riverside County comes from its use of now obsolete steam-cooled 7H turbines, which never made a dent in the global gas-fired generation market. GE has since begun using an HA (air-cooled) turbine that has a faster start-up, required with the increased use of solar and wind generation sources.

A combination of continuing shrinking power margins in California and the increasing need for fast-start capability has made the former GE technology less feasible today than 10 years ago.

GE power unit spokesperson Adam Tucker, told NGI that the Inland Empire facility had been operating below its original 750 MW capacity for several years after mothballing one of the two 7H combined-cycle units.

The plant, he said, “is powered by a legacy gas turbine technology that is the only 60-Hertz version of its kind globally and is uneconomical to support further.” GE is helping the operators using 7H technology sites to upgrade.

The plant site is being sold to an undisclosed developer that is considering a battery storage operation.

California Independent System Operator (CAISO) spokesperson Anne Gonzales said the grid operator's engineers have not found any reliability concerns in the region as a result of GE's decision to retire the plant. However, "CAISO shares the concern” of the California Public Utilities Commission (CPUC) “about overall system capacity,” which was noted in a ruling by CPUC earlier this month. CAISO is "closely monitoring" the situation.

California Energy Commission spokesperson Michael Ward confirmed GE's contention that the retirement is tied to technology more than California's climate change policies. He said GE has referred to the 7H turbines used in the Inland Empire as "orphaned technology."