Energy Storage Systems secures $3.2 million flow battery VC funding

Energy Storage Systems (ESS), the Oregon-based developer of battery solutions, has closed this week a Series A round of financing, securing $3.2 million in venture capital (VC) funding from Pangaea Ventures for its All-Iron Redox Flow Battery (IFB).

The funding is in addition to a further $4.5 million that ESS has secured in development grants for the commercialization of the IFP. Pangaea joins ARPA-e, ONAMI and Oregon Best as identified backers of the product, which has been designed for the long-duration energy storage market, ie, those that require greater than four hours of energy capacity and high numbers of cycles. The IFB can deliver 10,000 cycles with no degradation, and can store between 6 to 12 hours of energy.

ESS will use the funding to ramp up production of its 125 kW/1 MWh IFB system in 2016, targeting developed solar markets globally where PV is close to grid parity and thus has a greater demand for affordable and effective storage solutions.

"Combined with our confidence in the cost-effectiveness of the all-iron chemistry to support the low LCOE requirements of ESS’ customers, it was an easy decision for us to partner with them in their transition to a commercially focused company," said Pangaea Partner Andrew Haughian.

The IFB can deliver low-cost-per-kWh energy storage, ESS claims, and can time shift bulk energy from solar to enable much deeper renewable penetration on power grids. "As PV reaches grid parity in many markets, low-cost energy storage that buffers the intermittencies out will be a key enabler for the shift to renewable generation,” said ESS CEO Craig Evans.

The advantage of flow batteries over lithium-ion, which is widely considered the market leader in the solar+storage space, is that flow batteries can deliver a longer duration of storage at a competitive cost-per-kW basis, but underperform in terms of efficiency when compared to lithium-ion, delivering an energy-in/energy-out ratio of around 70%, compared to lithium’s 90% range.

Batteries on the charge

A report by Cairn Energy Research Advisors expects the global stationary storage market to increase by around 50% in 2016, and will grow from a global revenue of $6.7 billion this year to $13.2 billion by 2020.

The Cairn report cites the changing nature of load demand – caused by the intermittency of solar and other renewable energies feeding global electricity grids – as the reason why energy storage will soar.

"Generation is becoming more unpredictable and less flexible, while demand is becoming more responsive thanks to new forms of price signals such as demand response and time-of-use rates," the report said. "At the same time, more renewables are being absorbed by the electricity system and being buffered by batteries."