The capacity value of renewable energy plants is not the same as of their capacity rating. This is because despite their capacity being available for generation, renewable energy plants are energy constrained due to the intermittancy and unavailability of renewable resource. In planning the power generation system and for estimating the reliability of the system it is of utmost importance to know the capacity value of renewable energy candidate-plants that may be used in expanding the generation system. There are several methods to estimate capacity value or credit and one of the most common and accurate method is effective load carrying capability (ELCC). In this paper a three-step procedure for the calculation of the capacity credit for PV system using the ELCC technique is implemented through a small system of three conventional generating units and a PV plant. The paper is written in a way that is easy to follow. In this way, it represents a stand-alone lesson on capacity credit that is appropriate for undergraduate students and useful for post-graduate students who wants to pursue research in this area.