Primus Power is a producer of Big Batteries for the Smart Grid: sustainable liquid batteries used for energy storage on the electric grid. The venture backed company is based in Hayward, California and has developed a zinc based flow battery, called the EnergyPod, with support from the Department of Energy. The EnergyPod can scale from 25kW to 25MW for use on corporate campus or on site next to the substation, wind farm, or solar farm. The low maintenance Primus Power batteries allow five hour discharge and twenty year life span, necessary for grid applications.  Primus is developing projects for Puget Sound Energy and Bonneville Power Administration and The Marine Corps Airstation in Miramar, California. The company shipped its first system to Asia in early 2015. Primus signed a partnership with Microsoft in 2016 to supply battery support for Microsoft datacenters globally.
The company has raised more than $80 million in venture funds and government backed grants and is manufacturing systems for customers. The Company's energy storage systems decouple instantaneous electricity demand from supply generation, bolstering the stability and security of the electric grid, and helping accelerate the penetration of wind and solar energy. The company has numerous patents in chemistry, cell design, and system engineering, which make the energy density greater while improving reliability and life span thus enhancing the price /performance.
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9. Primus Gets A $20M Jolt for Energy Storage http://techcrunch.com/2014/02/04/primus-power-gets-a-20m-jolt-for-grid-scale-energy-storage/