Flow battery maker Primus Power raises $32 million

While lithium-ion batteries currently dominate grid-tied energy storage applications from the residential to utility-scale, there is no shortage of interest in alternatives. In particular, flow batteries by companies such as Germany’s Gildemeister and ViZn Energy have attracted a lot of attention over the last few years.

At times, they are attracting respectable investments as well. Late yesterday, California flow-battery-maker Primus Power announced that it has secured $32 million in equity financing in a round that includes new investors such as Hong-Kong based Success Dragon and Matador Capital.

There were also recurring names in this round, including DBL Partners, Anglo American Platinum, 12BF and the Kazakhstan Nanotechnology Fund. All told, Primus has raised $94 million in equity since it was founded in 2009 and has additionally secured $20 million in government grants.

Primus Power says that it will use the new funds to help “accelerate the commercial momentum” of its EnergyPod 2 battery system, which is based on the company’s zinc-bromide flow batteries. Among the aims of Primus Power is to introduce its flow batteries into the Chinese market, and the company notes that its batteries’ five-hour rating works well for the sort of applications that are important to support the integration of large amounts of renewable energy.

This appears to have been an important motivator for Success Dragon, for which this is its first foray into renewable energy.

“The energy storage market in China is still in its infancy and is set for rapid growth, given the country’s large-scale investment in renewable energy,” states Success Dragon Chair Ms. Li Xuehua. “We are confident that our partnership with Primus will give us a pioneering advantage and will see us emerge as a key player in China’s energy storage market.”

An advantage claimed by flow batteries is long life, particularly the ability to last through many more charge-discharge cycles than standard lithium-ion technology. Primus Power claims a 20-year lifetime for its zinc-bromide batteries and also notes the chemistry’s fire safety.