Carbon Emission Accounting and Low-Carbon Retrofit Evaluation of Power Grid Projects Based on Improved PSO-DRESN Method

Power Grid Projects (PGPs) are pivotal to energy transition, yet their complex engineering structures hinder precise carbon quantification. This study proposes a modular carbon emission accounting and evaluation framework for different types of PGPs. By deconstructing projects into 11 typical modules, we establish a modular-lifecycle that aligns physical engineering logic with carbon characteristic extraction. The research develops an automated method-matching engine and utilizes an Improved Particle Swarm Optimization-Deep Reservoir Echo State Network (IPSO-DRESN) model to determine modular carbon quotas with high precision. Empirical analysis reveals that the total lifecycle footprint of 500kV PGP is 13,569.1 tCO2e. The Operation and Maintenance (O&M) phase is the dominant emission source (54.4%), while the Production and Construction (P&C) phase (38.2%) is characterized by intense mechanical energy consumption. This research further establishes a low-carbon retrofit evaluation system, identifying high-capacity conductors and low-loss transformers as the most “carbon-elastic” interventions. By transforming fragmented engineering data into standardized modular quotas, this study provides a rigorous scientific tool for utility managers to implement lifecycle-based carbon benchmarks and optimize decarbonization strategies in the power sector.