AES, the US-based power generation and distribution giant, will build 37.5MW of battery storage at two of SDG&E’s existing substation facilities around the San Diego area, including a 30MW array in Escondido that will be the country’s largest.

AES will source the batteries themselves from Samsung SDI and the power-conversion systems from Parker Hannifin. Both projects are due online next year, with SDG&E to assume ownership.

SDG&E, owned by Sempra Energy, supplies electricity to more than 3 million people in southern California, with more than one-third of the power it delivers now coming from wind and solar.

“These batteries will help smoothly integrate this growing supply of clean energy onto the power grid for use by our customers,” says James P. Avery, chief development officer at SDG&E.

The AES-built systems will be able to provide SDG&E with 37.5MW of power continuously for four hours.

In addition to its 35GW of generating capacity and its distribution arms around the world, Virginia-based AES has become a leading global battery-storage developer and integrator, having built storage projects recently in the US, Northern Ireland and the Netherlands.

AES claims to have built 136MW of storage projects to date, with another 296MW under construction or in late-stage development. AES builds grid-scale battery projects for its own ownership as well as for external customers, such as SDG&E.

The order from SDG&E is the biggest to date for AES’s Advancion 4 storage platform, launched late last year. The fourth-generation technology has several advantages over its predecessor, including its smaller physical footprint, its modularity, and its ability to use batteries and inverters from a range of suppliers.

AES deployed its Advancion 4 technology for the first time at a commercial project late last year at the 10MW Warrior Run array in Maryland, using batteries from LG Chem.

“AES recently made Advancion available to utilities, developers and commercial customers interested in owning our innovative and scalable solution, and SDG&E’s selection of Advancion highlights the significant growth potential we see for our energy storage business,” says AES chief executive Andrés Gluski.