Flow-battery startup EnerVault announced a $15 million round of funding Thursday, which will help the company move forward with its first energy storage system installation.

Flow batteries aren’t well known, but they can be powerful energy storage devices. Instead of the typical, expensive lithium-ion battery, which powers most of the devices we use daily such as cell phones and laptops and often has a limited capacity, flow batteries are cheaper and can be scaled up to storage huge amounts of energy.

The technology behind them can be a bit complicated to understand if you don’t have a science degree, but essentially flow batteries generate electricity from electrolyte liquid flowing through a fuel cell. The liquid is stored in two external tanks next to the cell, and can be replaced when needed.

EnerVault has been developing large-scale redox flow batteries to power big buildings and support existing power grids. Its current plans involve the development and installation of a one-megawatt-hour flow battery system in the Central Valley of California.

“There is a high level of interest in our systems for addressing the stationary energy storage market,” EnerVault CEO and Co-Founder Dr. Craig R. Horne said in a statement, “Utilizing our patented Engineered Cascade(TM) technology, we are able to develop large-scale energy storage systems needed in a variety of applications with an unmatched combination of cost-effectiveness, safety and reliability.”

EnerVault was found in 2008 and has raised $24.5 million dollars over all from Mitsui Global Investment, Total Energy Ventures, 3M Company, TEL Venture Capital, Commercial Energy of California, Oceanshore Ventures, and US Invest. The company is based in Sunnyvale, California.

Stack of batteries image via Shutterstock