World’s First Flow Battery Captures and Stores Renewable Energy

Diagram of a Flow Battery


June 12, 2014

EnerVault, a California-based startup that makes battery technologies to support large-scale electrical utilities recently unveiled a flow battery demonstration project that the company is positioning as superior to lithium-ion systems. This is the biggest test yet of the company’s flow battery technology, which stores chemical energy and generates electricity by passing charged liquid through a barrier.

While the 1-megawatt-hour demonstration project may seem insignificant, it offers the potential for a viable solution to the energy industry’s perpetual storage questions—a challenge that likely will be solved by lithium-ion batteries or emerging technologies like EnerVault’s flow battery.

Today’s electrical grid is limited in its ability to store energy, primarily due to technological restraints. Most electricity must be used as soon as it is generated, requiring power plants to generate electricity at a steady or at least predictable rate. However, as grid operators continue to add renewable energy sources to their systems, they must figure out a way to capture and store energy when demand is low and release energy as demand increases.

Companies such as EnerVault are looking to sell flow battery technology to utilities, which are investing in various storage technologies to help manage the variable supply of renewable energy. EnerVault’s flow batteries have some properties that make them ideal for grid-scale storage: they can essentially hold a charge forever, the battery chemistry is cheap, and, in contrast to lithium-ion batteries, they are non-flammable and relatively non-toxic.

Lithium-ion batteries have the advantage of being a more mature and proven technology, and costs are expected to fall as more production capability comes online. Which battery technology prevails is a billion-dollar question: the grid-scale battery technology market is predicted to grow from today’s $164 million to more than $2.5 billion by the early 2020’s.