Is more aggregated better? Balancing power generation, employment accessibility, and climate mitigation in photovoltaic deployment

The rapid expansion of photovoltaic (PV) deployment, together with its growing concentration in large renewable-energy bases, has intensified the need to reassess PV land-use value. However, whether greater spatial aggregation consistently improves power, employment, and climate outcomes remains unclear. Here, we integrated multi-source geospatial data from 30,023 PV plants across China to build a site-to-region framework. This framework links PV aggregation to power-generation potential, population-based local accessibility, and net climate-mitigation benefit, and summarizes their joint performance as total composite benefit (TCB). We found a climate-specific non-linear pattern: TCB peaked at high aggregation in humid and sub-humid regions (76.7% and 62.1%, respectively), but declined monotonically with further aggregation in arid regions. Across regions, aggregation delivered larger gains in power-generation potential than in local accessibility or climate mitigation, and this imbalance became stronger as aggregation increased. Current deployment often falls outside the empirically identified high-benefit aggregation ranges, including 64.0% of PV capacity (42.9 GW) in arid high-demand areas and 87.1% (89.17 GW) in sub-humid flat terrains. These findings show that more concentrated PV deployment is not necessarily associated with greater land-use value. Our framework provides empirical benchmarks for evaluating PV aggregation and informing more balanced PV deployment across power-generation potential, local employment accessibility, and climate outcomes.