Viability limits of the renewable source in an electricity mix: The MIXOPTIM analysis methodology Bernard Bonin, Axel Laureau, Guillaume Krivtchik, Gilles Bordier, Henri Safa, Elsa Merle, Joachim Miss, Yann Richet and François-Marie Bréon Eur. Phys. J. Plus, 134 12 (2019) 614 Published online: 09 December 2019 DOI: 10.1140/epjp/i2019-12942-1