The aggregated leapfrogging estimate: a novel approach to defining energy leapfroggingSam Hosseini-Moghaddam, Branav Gnanamoorthy, Thomas Liang, Harry Cheng and Luc BernierRenew. Energy Environ. Sustain., 8 (2023) 17DOI: https://doi.org/10.1051/rees/2023017