Sizable Energy, an innovative ocean energy storage company, has successfully secured million in funding to advance its groundbreaking long-duration offshore pumped hydro system. This significant investment round was spearheaded by Playground Global, with additional contributions from Exa Ventures, Verve Ventures, Satgana, EDEN/IAG, and Unruly Capital. The capital infusion is set to propel Sizable Energy from its successful wave basin tests at the Maritime Research Institute Netherlands (MARIN) to comprehensive sea trials near Reggio Calabria, Italy.

This pioneering technology reimagines traditional pumped hydro storage by utilizing the vastness of the ocean. Instead of relying on freshwater and dam constructions, Sizable Energy’s system employs saturated sea-salt brine, which is approximately 20% denser than regular seawater. This brine is dynamically moved between a floating reservoir and a deep-water reservoir, effectively harnessing gravity and the immense depth of the ocean. This method allows for the storage and release of gigawatt-scale power, circumventing the extensive land use and environmental impacts typically associated with onshore hydro projects. Dr. Manuele Aufiero, CEO and co-founder of Sizable Energy, highlights the system’s potential to fortify the grid against the fluctuating nature of renewable energy sources, stating that affordable, long-duration storage is crucial for a stable, resilient, and future-ready energy infrastructure. The company asserts that its system offers the lowest Levelized Cost of Storage (LCOS) among long-duration storage technologies, even when compared to optimistic projections for lithium-ion battery costs. Its design integrates readily available materials, allowing for manufacturing, assembly, and deployment at depths exceeding 500 meters, leveraging existing maritime infrastructure.

Following its successful concept validation in laboratory settings and at MARIN, where the system demonstrated resilience in harsh ocean conditions, Sizable Energy is now progressing with a new prototype test in the Mediterranean. This pilot project, situated off Reggio Calabria, Italy, is designed to confirm the efficacy of its floating system, assembly processes, and deployment techniques. This critical step is intended to pave the way for a multi-megawatt demonstration plant in the Mediterranean Sea. Looking ahead, the company aims to initiate commercial project development by 2026 across multiple global locations. This expansion will involve collaborations with governments, energy providers, and local manufacturers to scale up long-duration ocean energy storage solutions.

Sizable Energy's innovative approach to energy storage, by transforming ocean depth into a sustainable power reserve, represents a monumental stride towards a more sustainable and resilient global energy landscape. By effectively addressing the intermittency challenges of renewable energy, this technology not only promises economic viability but also underscores humanity's ingenuity in leveraging natural resources responsibly, paving the way for a future powered by clean, stable, and abundant energy.