Traditional energy storage system construction processes are often slow, costly, and prone to inefficiencies. Because of this, there is a growing need for innovative solutions to streamline construction. This research aims to develop and optimize a site simulation methodology and a digitized planning platform, known as the “Plant Configurator”. The research will involve engaging with construction firms and suppliers for feedback, collaboratively improving design for constructability, and developing the “Plant Configurator” for modularized construction planning. The methodology will incorporate quantitative analysis, stakeholder collaboration, and digital platform development. The goal is to improve construction efficiency, reduce costs, and accelerate project timelines while ensuring constructability and alignment with real-world conditions. The developed digital solution is partially validated in collaboration with Malta Inc. and applied to a case study project of their Pumped Heat Energy Storage (PHES) design. The project addresses critical challenges in the energy storage sector by offering a novel approach to construction planning and simulation. Streamlining construction processes will help meet the increasing demand for long-duration energy storage, driven by the integration of renewable energy sources into the grid. The digitized platform represents an innovative solution to large-scale modular construction planning, enabling rapid turnaround planning cycles and automated lifting plans, and simulations. The research aims to provide a practical and adaptable solution for modularized construction planning, with the potential for substantial cost savings and increased efficiency in the sector.