The integration of renewable energy sources (RES) plays an important role for Portugal to respond to the future needs of energy demand in a sustainable way. RES should contribute to a consistent supply of energy and accessible to all, security of supply and an environmentally friendly system. However, a successful inclusion of RES in the current infrastructure is a complex process due to several barriers which requires the creation of a resilient plan. This plan should provide a satisfactory trajectory to the objectives stipulated while considering the risks involved. This paper explores how the integration of renewable energies impacts on the resilience of the Portuguese electricity system through the evaluation of scenarios for 2030. The influence of the risks in the scenarios was addressed by combining deterministic results obtained with Energy-PLAN and Monte Carlo simulation with the @Risk software. The results show that the electric system is vulnerable to the variability of the RES power in the future which may result on excess of electricity production or load curtailment, depending on the availability of the resources. The importance of the interconnection is highlighted for an effective management of the electricity system. Nonetheless, this RES strategy brings clear benefits in the environmental sphere, reducing CO2 emissions even in pessimistic scenarios.