This paper presents a composite generation and transmission system reliability evaluation method incorporating multiple correlations among wind speeds, insolations and bus/regional load curves. The proposed method can accurately model any probability distribution and all the correlations between wind speeds, between solar insolations, between load curves, between wind speeds and solar insolations, between wind speeds and load curves, and between solar insolations and load curves. The IEEE-Reliability Test System (RTS) with additional two wind farms and two PV power stations is used to demonstrate the application of the presented method in composite system reliability evaluation. (C) 2013 Elsevier Ltd. All rights reserved.