Sizable

Sizable Energy develops gigawatt-scale offshore pumped hydro energy storage systems that adapt proven pumped hydro technology for marine environments. The company's patented ABYSS system stores energy by pumping high-density saturated sea-salt brine between seabed reservoirs and surface floating reservoirs at ocean depths of several hundred meters, enabling long-duration energy storage with zero land use. Targeting grid operators and renewable energy developers, Sizable's modular design allows power and capacity to be scaled independently, supporting integration of large-scale intermittent solar and wind generation. Founded in 2022 by engineers from nuclear, mechanical, energy, and maritime fields, the company has validated its technology through wave-basin tests at MARIN and is conducting sea trials off Reggio Calabria, Italy.