Grid-Supporting Equipment Supply Chains Constrain the Feasible Pace of Power System Expansion

Abstract

Power system expansion depends on the equipment required to connect, convert, regulate, and condition electricity, yet grid-supporting equipment (GSE) is rarely modeled as an explicit constraint. We develop a framework integrating dynamic stock-flow modeling, BOM compilation and material intensity derivation, multi-regional supply-use analysis, and GSE deployment modeling to quantify GSE deployment requirements and upstream material dependence. Because manufacturing information is often fragmented or proprietary, we use critical material availability as physical proxy of GSE supply constraints. In a U.S. case study, GSE shortages reach 269.6--274.1 GVA (28.5%--28.6%) by 2030 under high-growth conditions. Copper is the first material to limit GSE availability from 2027 onward, while steel and nickel become additional constraints later. Trade disruption intensifies shortages, while dynamic transformer rating provides targeted but partial relief. These results show that grid expansion depends on the timely manufacturability, replacement, and material support of GSE, motivating planning frameworks that explicitly incorporate deliverability, supply chain exposure, and resilience strategies.