Towards a sustainable global energy supply infrastructure: Net energy balance and density considerations

► We model the growth potential of alternative electricity supply infrastructures. ► Coal is scalable and abundant but carries a heavy carbon footprint. ► Renewables and nuclear meet the longevity and environmental friendliness criteria. ► The low power density and intermittency of renewables limit their growth potential. ► Nuclear power continues to raise concerns about proliferation, safety, and waste.