This technical assistance will support the Philippines Department of Energy in assessing the potential for seawater energy storage systems in the Philippines. Two work packages are being tendered as part of the overall initiative Enhancing Hydro Energy Storage Viability. The implementing partners of these two work packages are expected to collaborate, where applicable, to deliver the expected project outputs. This Terms of Reference (TOR) document refers to Work Package 2 covering seawater pump storage hydro (PSH). Work Package 2 focuses on assessing the techno-economic feasibility, viability, and stocktaking of potential seawater PSH areas. Relevant information dissemination activities will be organised. This project is being implemented to maximise the potential of PSH as the long-term and sustainable energy storage solution for the Philippines grid that is expected to take in variable renewable energy capacity. Identifying solutions that would support renewable energy integration into the grid is essential for the Philippines’ energy transition.