This Stem eBook shows how developers, asset owners, and independent power producers can leverage a modular approach to. This Stem eBook shows how developers, asset owners, and independent power producers can leverage a modular approach to. Battery storage is a technology that enables power system operators and utilities to store energy for later use. The Need for Grid-Connected BESS Integrating renewable energy. . The future of renewable energy relies on large-scale industrial energy storage. Unlike residential or commercial-scale storage, utility-scale systems operate at multi-megawatt (MW) and multi-megawatt-hour (MWh) levels, delivering grid-level flexibility, reliability, and. .