Conventional methods used in project evaluation have a static nature, which cause decision makers to examine investment projects within a narrow scope. As an alternative, real-options theory allows decision makers to use the concepts of uncertainty and managerial flexibility, which classical methods do not deal with, in valuing investment projects. Carlsson and Fuller's fuzzy real-options theory has been a solution for situations where cash flow and cost variables used in the model cannot be expressed by using classical numbers but by using fuzzy numbers. The idea of using intuitionistic fuzzy numbers in real options theory can expand the narrow scope more effectively than the idea of using classical real-options theory, thereby providing an opportunity to evaluate investment projects from a wider perspective. In this study, intuitionistic fuzzy real-option valuation model has been developed and applied to the evaluation of solar energy investment projects. Studies have shown that solar energy investments that do not seem profitable today in Turkey can perform profitably in the future. Moreover, the historical volatility model differs from the expected valuable models, whereas the optimum investment year between the models formed by the uncertainty inductions from the expected values exhibit minimal difference.