The integration of renewable energy systems has increased in the last decades because of the need for new energy sources freely available and environmental friendly. In this sense, photovoltaic-wind hybrid energy systems are an attractive solution, especially in places with good sun and wind resources. However, due to the stochastic and intermittent behavior of these sources, it is necessary to analyze systems' reliability. In this paper, a new reliability indicator is proposed, based on the minimum hourly electric power obtained from the wind and solar radiation using a probabilistic approach. This indicator is compared with other indicators and the results showed that it increases system reliability by maximizing the use of renewable sources.