EnerVenue Holding, backed by Aramco Ventures, is accelerating its Middle East push after closing a $300 million extension of its Series B preferred stock financing round led by Hong Kong-based Full Vision Capital. The California-based long-duration energy storage startup said the fundraising will support rapid scale-up of manufacturing in Changzhou, China, and accelerate supply-chain development and commercial expansion as it targets markets in the Gulf, particularly Saudi Arabia. "Aramco Ventures was an early investor starting with Series A and has participated in subsequent opportunities," EnerVenue’s newly appointed CEO Henning Rath told AGBI, underscoring the deepening ties between the startup and Saudi Aramco's venture arm. EnerVenue said the Series B extension follows a $100 million Series A round raised in September 2021. The company makes aqueous metal cells — low-cost, water-based electrolyte storage devices — designed to provide long-duration energy storage with high-efficiency operation and without the energy-intensive cooling systems required by lithium-ion batteries. Company plans and regional positioning Rath described significant opportunity in the Middle East, citing close business relationships with regional integrators and energy investors. He noted the region's strong solar resource base and heavy investment in renewables and battery storage, but added that deployment faces operational challenges such as "rapid load growth under high temperatures." Funding: $300 million Series B extension led by Full Vision Capital; prior Series A of $100 million in September 2021. Manufacturing: Scale-up of an initial line in Changzhou, China, a hub for battery manufacturing. Technology: Aqueous metal cells aimed at long-duration storage without intensive cooling. Regional focus: Plans for commercial pilot projects in the Middle East, with particular emphasis on Saudi Arabia. EnerVenue is already engaged with several energy-related entities in the region and sai…