Lifecycle carbon-footprint hotspots and decarbonization conditions in transmission and distribution equipment: A case-based analysis

Lifecycle decarbonization of transmission and distribution equipment requires evidence that connects carbon hotspots to the engineering variables and service conditions that govern them. We analyze 11 numerically reconstructable cases spanning voltage transformation, switching/protection, and power transfer by overhead line or cable. Transformer operation dominated the examined cases, while alternative core designs showed load-dependent benefits governed by no-load and load losses. In switching equipment, lower-gas technologies depended jointly on gas release, auxiliary electricity, and production burdens. Line and cable evidence showed that conductor and dielectric losses must be considered alongside material and civil-infrastructure demands. Across the cases, reductions in one lifecycle term could shift burdens elsewhere unless alternatives were evaluated on matched functions and service conditions. By linking hotspots to controllable variables, the analysis identifies requirements for duty-matched transformer design, joint gas-and-auxiliary management, and whole-product or whole-route evaluation. These service-conditioned findings strengthen lifecycle carbon decisions in equipment design, procurement, and operation.