In this paper, we analyze the generation, storage and transmission expansion of the isolated power system of Las Palmas (Spain) for 2050. This power system comprises two isolated systems: Lanzarote-Fuerteventura and Gran Canaria. The generating, storage and transmission capacity to be built is determined by solving a two-stage stochastic investment model taking into account different long-term uncertain parameters: investment costs of immature technologies of power production and storage, annual demand growth, number of electric vehicles, rooftop solar penetration and natural gas prices. The possibility of linking together the isolated power systems of Lanzarote-Fuerteventura and Gran Canaria for reaching a higher penetration of renewable units is also considered. The operation of the power system is simulated by considering the day-ahead energy and reserve capacity markets. The variability of the hourly available wind and solar power, and the demand level are modeled by using a set of characteristic days to represent the target year. The performance of the resulting power system is assessed by conducting an out-of-sample analysis using the AC model of the power system. The numerical results show that a future configuration of Las Palmas power system mainly based on solar and wind power units can be achieved with the support of gas units and storage.