Advances in Renewable Energy System Integration in China: A Four-Dimensional Analysis (2020–2026)

The article examines progress in the system integration of renewable energy sources in China over the period 2020–2026, focusing on the challenge of integrating rapidly expanding renewable energy capacity into the power system. The study adopts a review-based and synthetic approach, combining a structured narrative review, based on an explicit search and eligibility protocol, with the analysis of secondary quantitative data and selected case studies. The analysis covers four interrelated dimensions of system integration—temporal, spatial, technical and institutional-market—each assessed using a common framework of input/capacity, enabling-system and integration outcome indicators. Comparison of the 2020 baseline with end-2025 data, supplemented by qualitative updates to September 2026, reveals a substantial transformation in China’s power system. By the end of 2025, combined wind and solar PV capacity had reached approximately 1.84 TW, accounting for 47.3% of total installed capacity, while new-type energy storage capacity increased from approximately 3.3 GW in 2020 to approximately 136 GW in 2025. The findings reveal clearly differentiated development trajectories across the four dimensions. Rapid expansion of renewable energy capacity and energy storage was accompanied by persistent spatial integration constraints, a still limited documented scale of grid-forming deployments and gradual development of institutional and market mechanisms. The analysis indicates that rapid capacity and infrastructure growth does not necessarily translate into equally rapid progress in system integration, highlighting the importance of coordinated resource utilisation, power system stability and effective market mechanisms.