Due to climate change, shifting from conventional generation sources to new renewable energy production has become important. Power systems are becoming more susceptible to issues with low inertia due to increased reliance rates on renewable energy sources (RESs). Fractional order has recently attracted a lot of interest and investigation. As a result, dynamic systems and controllers with fractional order (FO) are becoming more popular. The responsiveness and stability of the load frequency control (LFC) system are enhanced in this article using FO controllers. The performance of the proposed fractional order proportional-integral-derivative (FOPID) controller is compared against the conventional proportional-integral-derivative (PID) controller. The optimal gain values of the two controllers will be optimized utilizing the marine predator optimization algorithm (MPA), and a performance comparison was carried out with several objective functions. After comparing the settling times, overshoot, undershoot, oscillation of frequency deviation, and tie-line power of the single and dual-area hybrid power systems (SAHPS & DAHPS), it is possible to conclude that, in the occurrence of load disturbance changes and the widespread use of RESs, the suggested FOPID controller performs more effectively and is more robust than the conventional controller. It minimized the ISE after 32 iterations with 83.73%, IAE with 75%, ITSE with 93.77%, and ITAE with 83.58% compared to the PID controller at load variation.