Distributional trade-offs between regionally equitable and cost-efficient allocation of renewable electricity generation

•Distributional impacts assessed for decentralized renewable generation (DREG).•Large trade-offs found between cost-efficient vs. regionally equitable allocation.•Least-cost allocation implies concentrating DREG to few most productive sites only.•Solar PV is key for more regional equity with small trade-offs in generation costs.•Policies for cost-efficient DREG allocation risk strengthening regional disparities.