It is important to estimate the contribution of renewable generation units in the evaluation of system generation adequacy for power generation planning taking into account the demand and renewable generation correlation and uncertainty. The effective load carrying capability (ELCC) is usually used for this purpose. In this paper, a noniterative analytical method is proposed for estimating the peak load carrying capability (PLCC) and ELCC of conventional and renewable generation units. The proposed method is verified using the IEEE RTS and an electricity network in New South Wales, Australia, and the results are compared with other estimation methods. The results show that the correlation between demand and renewable generation influences the ELCC of a renewable generation unit - the higher the correlation, the higher the ELCC, and vice versa. The main contribution of this paper is the development of an analytical noniterative and computationally efficient technique, which accounts for the correlation between demand and available renewable generation. © 2014 IEEE.