Eos Energy Storage announced this week that it has raised $15 million from a syndicate of 21 investors in a new round of financing. The new funds will support the commercialization of the company’s Aurora grid-scale energy storage product.

The Aurora system, which is based on an innovative zinc hybrid cathode battery technology, is delivered in a standard 40-foot shipping container, and comes in 1 MWh and 6 MWh sizes. It’s designed to operate for at least 10,000 full cycles, or 30 calendar years, and initial pricing is $160/kWh. Eos is in discussions with several states regarding the location of its pilot manufacturing facilities, and expects to begin deploying the Aurora in 2014.

Eos says that its proprietary Znyth technology has delivered the most cycles of any metal-air battery – over 5,000 to date with no physical degradation – and that it is safe, stable, environmentally-friendly, and offers major cost savings. The company is also developing the Vista zinc flow battery, which is targeted at EV applications.

One of the investors in this round is New Jersey-based NRG Energy (NYSE: NRG). This represents its first investment in the energy storage industry. “Eos’s technology is of strategic interest to NRG as we seek to enhance the value of our generation assets and evaluate novel energy storage business opportunities,” said NRG Executive VP Denise Wilson. “We have confidence in Eos’s technology, its management team and the compelling value proposition the company will provide to the marketplace.”

Another investor is the real estate concern Fisher Brothers. “Energy storage can bring building operations and the electricity grid into the 21st century. Eos’s groundbreaking technology will reduce costs for building owners and help integrate renewable energy on the grid,” said partner Winston Fisher. “Fisher Brothers’s investment in Eos is a natural extension of our commitment to develop energy storage assets benefiting our tenants, the environment and our bottom line.”

Sources: Eos, Green Car Congress