Mitsubishi Power and Powin Partner to Enhance California’s Grid Reliability with Two Battery Energy Storage Projects


Projects Will Add 640 MWh of Storage to Southern Power’s Solar Facilities

LAKE MARY, Fla. (May 4, 2021) – Southern Power has awarded Mitsubishi Power Americas, Inc. and Powin, LLC an order for two utility-scale battery energy storage system (BESS) projects totaling 640 megawatt hours (MWh). These projects will enhance California’s grid reliability with additional flexible resource capacity for integrating intermittent renewable energy into the grid. 

The BESS projects are among the first collocated solar and storage projects in California and represent some of the largest retrofits of solar and storage in North America to date. They are designed for a 20-year life cycle and four hours of energy storage duration. Southern Power’s 205 megawatt (MW) Garland Solar Facility in Kern County will add 88 MW and 352 MWh of energy storage, and its 204 MW Tranquillity Solar Facility in Fresno County will add 72 MW and 288 MWh. Both projects are scheduled to come online in 2021.

The energy storage projects will be owned in partnership with AIP Management and Global Atlantic Financial Group, both of which have existing ownership interests in the Garland and Tranquillity solar facilities that went into commercial operation in 2016. Southern Power operates the solar projects and will be responsible for operating the energy storage projects upon completion.

These two energy storage projects align with Southern Power’s growth strategy of developing and acquiring projects covered by long-term contracts with strong credit counterparties.

Geoff Brown, CEO of Powin, said, “We are pleased to continue our relationship with Mitsubishi Power and to have been selected as a trusted partner by Southern Power to provide BESS over the long-term for the Garland and Tranquillity projects. This award highlights the fact that large-scale solar PV paired with energy storage is cost competitive. We applaud Southern Power for taking this step toward helping California meet its clean energy goals with energy storage.”

Tom Cornell, Senior Vice President of Mitsubishi Power’s NEXT said, “Mitsubishi Power is excited to leverage our network of capabilities in the Americas and globally to bring low carbon solutions to Southern Power. These battery energy storage projects, which will use lithium iron phosphate technology, fit within our vision to provide short- and long-term energy storage solutions that include lithium ion, hydrogen, and other emerging storage technologies. We are proud to provide Southern Power with an energy storage solution to enhance the reliability of California’s electric power grid. Together with our customers and partners, we are creating a Change in Power.”

Southern Power

Mitsubishi Power Americas, Inc. and Powin, LLC are helping Southern Power enhance the reliability of renewable energy in California with two utility-scale battery energy storage system (BESS) projects. The projects totaling 640 megawatt hours will be installed at Southern Power’s Garland and Tranquillity Solar Facilities to provide additional flexible resource capacity for integrating intermittent renewable energy into the grid. (Credit: Mitsubishi Power)

About Mitsubishi Power Americas, Inc.

Mitsubishi Power Americas, Inc. headquartered in Lake Mary, Florida, employs more than 2,000 power generation, energy storage, and digital solutions experts and professionals. Our employees are focused on empowering customers to affordably and reliably combat climate change while also advancing human prosperity throughout North and South America. Mitsubishi Power’s power generation solutions include natural gas, steam, aero-derivative, geothermal, distributed renewable technologies, environmental controls, and services. Energy storage solutions include green hydrogen and battery energy storage systems. Mitsubishi Power also offers digital solutions that enable autonomous operations and maintenance of power assets. Mitsubishi Power, Ltd. is a wholly owned subsidiary of Mitsubishi Heavy Industries, Ltd. (MHI). Headquartered in Tokyo, Japan, MHI is one of the world’s leading heavy machinery manufacturers with engineering and manufacturing businesses spanning energy, infrastructure, transport, aerospace and defense. For more information, visit the Mitsubishi Power Americas website and follow us on LinkedIn.

About Powin, LLC

Powin is a global leader in the design and manufacture of safe and scalable battery energy storage solutions. For nearly the past decade, Powin has worked to advance its patented battery management technology and develop market leading product offerings. Headquartered in Tualatin, Oregon, Powin has built over 600 MWh of systems, supporting 54 projects in 10 states and 8 countries. Powin has a contracted pipeline to supply over 4,000 MWh of energy storage systems globally over the next five years. Powin’s journey is just beginning — if you are interested in learning more, please visit