Scenarios for refurbishment of a hydropower plant equipped with Francis turbines Sebastian Muntean, Romeo Susan-Resiga, Eberhard Göde, Alexandru Baya, Radu Terzi and Constantin Tîrşi Renew. Energy Environ. Sustain., 1 (2016) 30 Published online: 29 June 2016 DOI: 10.1051/rees/2016030