Renewable energy has had a steady growth in power systems worldwide. The high uncertainty about what type of renewable technology meets technical and economic variables of the energy markets and what could be the participation in the energy matrix are important long term energy planning challenges that need to be identified and evaluated. This work assesses different scenarios of future development of the Chilean electricity matrix and the technological contribution of renewables. They are formulated within the Chilean Central Interconnected System and determine the evolution of technological diversity variables, costs, CO2 emissions and energy injection. The scenarios illustrate the need to strengthen the transmission system and the importance of improving and / or incorporating mechanisms to reduce dependence on fossil fuels and the maximization of renewable resources in Chile. Future work will establish the impact of intermittent renewable technologies on power system operation. ©2010 IEEE.