Solar Power has become the main focus in effort to reduce dependence on limited fosil energy resources. However, solar panel still have drawbacks, namely that the power produced depends on changes in temperature and light intensity. This research uses Modified Maximum Power Point Tracking (MPPT) combined with Buck-Boost Converter to increase the efficiency of the solar power system. In this research, analyzer the performance comparison of the conventional Perturb And Observe (P&O) algorithm with the Modified Perturb And Observe (P&O) using a buck-boost converter. Test result show that the modified MPPT algorithm shows better efficiency, with an average efficiency reaching 97% when the radiation changes occur, while the conventional P&O algorithm reaches 96%. However, in test with load variations modified P&O algorithm is slightly superior with an average efficiency of 95.6% compared to the conventional P&O of 95%
