ESS CEO Eric Dresselhuys joined Renewable Energy World for a conversation about the company's journey, the promise of flow battery technology, and the impact of proposed tax credits for energy storage currently being considered by the U.S. Congress.

Earlier this month, ESS became the first U.S. long-duration energy storage company to list on the New York Stock Exchange. The company also inked a massive 2 GWh deal with SB Energy and reached an agreement to supply Enel Green Power with 17 battery systems in Spain.

Long-duration energy storage -- five hours or more -- is a crucial piece in the world's transition away from polluting fossil fuels toward renewable energy resources. While lithium-ion batteries currently dominate the market, there are safety and environmental concerns about sourcing and deployment of the technology, which is also limited to only discharge up to 4 hours.

ESS is targeting the 4-to-25 hours segment of long-duration energy storage.

SB Energy will deploy additional ESS battery systems to support solar power projects in Texas and California, where grid reliability issues have been front and center. (Courtesy: ESS)

Bill Gates' Breakthrough Energy Ventures is backing long-duration storage companies ESS, Form Energy, and Ambri, among others, while gravity-based energy storage firm Energy Vault is expected to list on the NYSE after a SPAC merger of its own, valuing the company at $1.1 billion.