The electric generation systems on islands are based generally on fossil fuel. This fact and its supply make the electricity cost higher than in systems used in the continent. In this article, we present a review of the renewable energy generation systems on islands. To do it we analysed 77 islands from 45 different countries. This work will allow us to know how the implementation of renewable energy sources could help these islands in developing a renewable and sustainable energy sector, including a reduction of electricity generation cost. This paper shows the results from a study case of the application of renewable energy technology in Cozumel Island, Mexico. This Island is located in front of the Riviera Maya area. The analysis was made through long- term statistical models. A deterministic methodology was used to perform time-series simulations. The simulations shows that for the year 2050 a feasible integration of a system based on wind/PV can be achieved on the Island, reducing the electricity price from 0.37 US$/kW h to 0.24 US$/kW h (2050 scenario). With this scenario, the government will achieve its targets in renewable energy and in the reduction of the emissions of CO2. This will allow reaching a sustainable electricity sector.