Alamitos Energy Center is a 1,040MW gas-fired power plant along with a 400MWh energy storage facility. Image courtesy of Kiewit Corporation.
Construction on the project was started in July 2017. Image courtesy of Kiewit Corporation.
Alamitos Energy Center is located at Long Beach, California, US. Image courtesy of Darkest tree.

Alamitos Energy Center (AEC) is a new 1,040MW gas-fired power plant along with a 400MWh of battery storage facility under-construction to replace an ageing gas-fired power station on Studebaker Road in Long Beach, California, US.

AES Alamitos, a subsidiary of AES Corporation, which also owns the existing facility, is developing the project with an estimated investment of £1.8bn ($2.3bn).

Construction on the first power block of the plant that comprises a 640MW combined-cycle generating unit was started in July 2017, while its commissioning is expected in the first half of 2020.

Construction on power block two, a 400MW simple-cycle generating unit, is expected to be started in the last quarter of 2020, with commissioning expected by the end of 2022.

AES Alamitos also started construction of the battery energy storage facility at the site in June 2019, which is expected to enter service in 2022. The existing Alamitos power station is scheduled to demolished from 2023 to 2026.

The project is expected to generate 447 construction jobs and up to 51 permanent jobs during operations.

Project background

AES Corporation acquired the existing Alamitos generating station, operational since the 1950s, from Southern California Edison in 1998.

AES decided to modernise its old power generation assets in compliance with the recent changes to California environmental law that mandated a significant reduction in the use of ocean water for cooling.

New environmental regulation and increasing power demand in southern California led to the proposal of replacing the existing Alamitos generating station with a modern and efficient facility.

The new facility will avoid the use of ocean water for cooling, use 70% lesser freshwater and 50% lesser fuel to generate the same amount of electricity compared to the existing facility.

The California Energy Commission (CEC) and South Coast Air Quality Management District approved the AEC project in April 2017.

Alamitos Energy Center make-up

The power block one of the Alamitos Energy Center, which is being developed at the existing AES Alamitos Generating Station site, will be a 640MW combined-cycle generating unit. It will be equipped with two gas turbine units, each paired with a heat recovery steam generator (HRSG), a steam turbine generator, an auxiliary boiler, and an air-cooled condenser.

The power block two will comprise four simple-cycle gas turbine units with a combined generation capacity of 400MW.

The 400MWh battery storage facility is being developed within a two-storey building that neither requires water nor generates noise pollution and emissions.

Gas and water supply

The Alamitos Energy Center will receive natural gas from an existing 30in-diameter pipeline owned by Southern California Gas Company.

The water required for the plant operations will be supplied through existing pipelines by the City of Long Beach Water Department.

Power transmission and off-take

The electricity generated by the facility will be evacuated using the existing 230kV Southern California Edison switchyard and associated transmission facilities located onsite.

Southern California Edison signed a power purchase agreement (PPA) with AES Corporation for 640MW from the power block one of the Alamitos Energy Center in 2017.


Out of the total project cost of £1.8bn ($2.3bn), approximately £1.6bn ($2bn) is arranged through long-term non-recourse financing, while AES Corporation funds the remaining project cost through equity investment.

Contractors involved

Kiewit Power Contractors has been engaged as the engineering, procurement, and construction (EPC) contractor, while NV5 was appointed to provide engineering design review and construction inspection services.

Fluence, a joint venture between Siemens and AES Corporation, is the provider of the energy storage system for the Alamitos Energy Center.