This paper develops a Hybrid Solar-Wind-Tidal optimization (HSWTO) model to optimize the capacity sizes of different components of power generations. For doing this, first of all the correlations between these energy quantities during different times of year are calculated. Furthermore reliability is considered as a separate objective here. Consequently, this model has two objective functions which are minimizing costs and maximizing reliability that is solved by epsilon-constraint method. At last, various scenarios about these renewable cost predictions including PRIMES, IEA and EPRI are utilized for obtaining optimistic pessimistic results. Moreover the model is executed for Iran-Mahshahr, where is such a striking place in terms of these three renewables. The results indicate that tidal is not feasible based on any of these three scenarios, but wind and solar are feasible.