A novel algorithm for maximum power point tracking (MPPT) in solar power-generating systems was proposed and compared with the conventional methods of hill climbing, perturbation and observation, and incremental conductance. The three conventional algorithms are prone to divergence under low irradiance levels (<150W/m2), resulting in MPPT difficulties. This study proposed a new MPPT technique based on the relationship between the sun and the horizon, and also circumvented the drawbacks of conventional MPPT algorithms. The proposed algorithm facilitated quick and precise convergence at the maximum power point for a photovoltaic module under a low irradiance level of 100W/m2. Comparisons of the proposed and conventional hill climbing algorithms were conducted for irradiance levels of 650, 500, 250, and 100 W/m2, and the proposed algorithm yielded consistently more favorable results than did the conventional hill climbing algorithm.