Research on the Non-linear Impact and Spatial Spillover of Urban Planning on Microgrid Decarbonization Effects

As urban energy systems evolve toward decentralization and decarbonization, microgrids have emerged as pivotal technologies for enhancing urban resilience and absorbing local renewable energy. However, existing literature largely privileges engineering perspectives, leaving the deep coupling mechanism between microgrids and the urban planning system underexplored. Adopting a "Technology-Space" coupling lens, this study employs panel data from Chinese cities to construct an inverted U-shaped model and a Spatial Durbin Model (SDM), empirically examining the moderating mechanism of urban planning quality on the carbon abatement effects of microgrids. The results indicate that: First, a significant inverted U-shaped non-linear relationship exists between microgrid penetration and carbon emission intensity, characterizing a trajectory of initial increase followed by a decline. Second, urban planning plays a decisive moderating role; high-level spatial planning, through compact layouts and functional mixing, significantly shifts the carbon peak inflection point to the left and amplifies abatement benefits, effectively avoiding the pitfalls of "patchwork" deployment common in low-planning contexts. Third, carbon emissions exhibit significant spatial spillovers, where optimized urban planning functions as a regional public good, driving emission reductions in neighboring cities through proximity effects. The study concludes that shifting from a singular technology-oriented approach to a holistic "Technology × Space" planning paradigm is critical. Energy facility layouts must be deeply embedded into the statutory urban planning system to accelerate the low-carbon transition of urban energy systems.