Funds Trickle Into Flow Batteries, EnerVault Raises First Round

Expect to see more attention on flow batteries in 2010, as investors, utilities and entrepreneurs look to the technology as a way to provide low cost energy storage to the power grid alongside the addition of clean power. Take EnerVault, a flow battery company we profiled last May. The startup recently raised its first round of $3.5 million in venture funding, from Oceanshore Ventures and U.S. Invest, according to a regulatory filing. (Previously the company won a $650,000 grant from the NY State Energy Research and Development Agency (NYSERDA)).

According to an executive summary from EnerVault, the company plans to use the funding to build a prototype that can demonstrate that their flow battery technology can scale to megawatts, as well as for adding on staff and attracting new customers. Once the prototype is built, EnerVault says it will look for follow-on and government funding to build a full-scale field-deployable system.

Why will flow batteries be so important for the future of the smart grid? The technology — which generally uses large storage tanks full of electrolytes and pumps that circulate the solution throughout the system — has had decades of research, could offer one of the lowest cost grid storage options out there, and can be safer and more reliable than other energy storage technologies like advanced batteries, which can become overheated.

EnerVault CEO Craig Horne told us last May that the company’s flow battery can run around $100 per kWh, but says that price could also come down when the company scales up production. In comparison, lithium-ion batteries can cost from $200 per kWh to $500 per kWh and up to $1,000 per kWh for more advanced batteries with more expensive materials.

Like other forms of grid energy storage, flow batteries will become increasingly important as utilities look to add clean power to their portfolios. In particular utilities that have state renewable portfolio standards will need to make sure that the intermittency of the clean power (the sun and wind are only available at certain times of day) that they add on doesn’t make their grids more vulnerable.

Other flow battery companies are raising funds, too. Last year flow battery maker Deeya Energy closed a $30 million financing round from Technology Partners, BlueRun Ventures, Draper Fisher Jurvetson and New Enterprise Associates. Deeya is a 5-year-old firm that hails redox flow battery inventor Lawrence Thaller as a technical adviser and has raised $53 million.

Image of flow battery courtesy of Electric Storage Association.