Mission design dictates whether solar power is enough to satisfy your requirements. For Curiosity, they wanted to go faster and longer with more power than solar would have given them considering the size of the rover (i.e. not much space to put solar panels on, which yields in lower power available).
Mission design dictates whether solar power is enough to satisfy your requirements. For Curiosity, they wanted to go faster and longer with more power than solar would have given them considering the size of the rover (i.e. not much space to put solar panels on, which yields in lower power available).