China's energy consumption trends and structural transition pathways under synergistic cost and carbon constraints: Based on the perspective of optimal steady economic growth

As a country long reliant on fossil fuels, China faces the dual challenge of maintaining steady economic growth while ensuring environmental protection. To address this issue, this study develops a coupled optimization framework that integrates both economic and energy objectives. The framework consists of two components: first, an optimal steady economic growth model that forecasts s optimal economic growth trajectories under both carbon-constrained and unconstrained scenarios and estimates the corresponding energy demand; second, a multi-objective energy structure optimization model that aims to minimize carbon emissions and energy costs, while incorporating energy substitution elasticity and a learning-curve-based cost function to capture the dynamic relationships among energy technologies, cost, and electricity demand. The two models achieve coordinated modeling of economic development and energy transition through an energy supply–demand balance mechanism, and further project the evolution of energy consumption, structure, and costs under carbon-constrained and unconstrained optimal economic growth scenarios. The results show that under carbon constraints, China's peak energy consumption is expected to occur four years earlier, along with substantial progress in coal phase-out, electrification, and reductions in levelized cost of electricity. The findings underscore that strict implementation of carbon reduction targets and accelerated deployment of clean energy technologies—particularly wind and photovoltaic power—are critical for achieving a coordinated pathway toward economic growth and environmental sustainability in China.