National-level assessment of infrastructure-coupled roadside solar energy toward transportation decarbonization in...

Decarbonizing transportation requires approaches that embed renewable generation into existing infrastructure. Here we show that roadside photovoltaic deployment along China's roads and railways can be quantified using a geospatial framework that links segmented transport corridors to meteorological grids. The approach maps 480,019 km of transport infrastructure to 4,133 meteorological grids and provides a scalable alternative to coarse regional averaging. Across all deployment scenarios, roadside photovoltaic systems could support 40.91-202.84 GW of installed capacity and generate 56.6-239.2 TWh of electricity annually. Under the baseline scenario, annual generation reaches about 100.6 TWh, equivalent to about 50% of current transport-sector electricity demand. The resulting carbon reduction reaches 33.62-143.97 Mt CO₂ annually. The results reveal strong regional heterogeneity, with North and Central China showing the highest near-term potential, while Northwest China could act as a generation-export region. These findings provide a basis for region-specific infrastructure planning and more coordinated transport-energy system integration.