U.S. Department of Energy - Energy Efficiency and Renewable Energy

Advanced Manufacturing Office – Industrial Distributed Energy

Primus Power's Flow Battery Powered by $11 Million in Private Investment

June 22, 2011

In February, the Advanced Research Projects Agency-Energy (ARPA-E) announced that six of its projects, which initially received a total of $23.6 million in agency seed funding, had collectively generated more than $100 million in outside private capital investment. ARPA-E recently received the news that another of its performers, Primus Power, has generated $11 million in follow-on funding for its grid-scale storage technology—five times more than ARPA-E's $2 million investment last year. As Secretary Chu has said about follow-on funding for ARPA-E projects, "This is precisely the innovation leverage that is needed to win the future."

Primus Power has developed a low-cost, distributed storage flow battery made of tanks filled with high energy density electrolytes that are pumped throughout the battery system. This flow battery can store renewable energy such as wind and solar power and then release that energy into the grid during peak load times. Since renewable energy is often variable, the ability to store this electricity to balance grid power is becoming significantly more important as renewables become more prevalent in the United States.

Primus Power is building a farm of flow batteries that promise to offer 25 megawatts of power for up to three hours for the Modesto Irrigation District (Modesto, California's utility provider). This battery farm will serve as a full-scale demonstration system, and it will store the region's wind-generated energy and provide an alternative to fossil-fuel-fired generation. See the Energy Blog post.