The Office of the US Trade Representative included lithium-ion batteries and static converters, both used in storage systems, in its May 13 list of items earmarked for a tariff increase.

The association said Thursday energy storage was one of the fastest-growing areas in the US energy sector and stressed the need for greater certainty for future investment and hiring decisions.

"Our innovative companies are changing the business model in the electric industry. And now is not the time to disrupt the international supply chain as we work to build a resilient, efficient, sustainable and affordable grid for all Americans," CEO Kelly Speakes-Backman said.

The proposed tariffs will stymie growth and job creation as energy storage projects already contracted are delayed or canceled. With this, higher costs and uncertainty would create barriers at a time when the demand for improved resilience and clean energy was rising across the nation, the association said.

"To maintain business continuity and growth in the storage sector, policymakers should not impose tariffs on batteries and related equipment. Instead, they should enact the plethora of existing bipartisan legislative efforts that have been introduced in statehouses across the country and in Congress," Speakes-Backman added.

"We look forward to working with officials to avoid the mistake of imposing tariffs that would hinder US efforts to modernise the American electric system."

According to the US International Trade Commission, the US imported more than US$1 billion worth of lithium-ion batteries from China in 2017.

According to the latest Wood Mackenzie US Energy Storage Monitor, the US energy storage market set a new growth record in the March-quarter, deploying 148.8MW; a 232% year-on-year increase and a 6% rise from the December-quarter of 2018.

The monitor also forecasts energy storage deployments in 2019 to double over 2018, and annual deployments to reach more than 4.5GW by 2024, creating a $4.8 billion market.