This study aimed to evaluate the energy policies and investments in renewable energy resources. In this context, developing energy policy and investing in energy were defined as two different factors for renewable energy. Additionally, eight different criteria were also selected based on these two different factors. In the first stage of the analysis, these criteria were evaluated by using a correlation coefficient based on interval type-2 fuzzy sets. The findings show that five criteria have a relationship with policy factors, whereas seven criteria are related to the investment factor. After that, the fuzzy DEMATEL approach based on interval type-2 fuzzy sets were used to weight these criteria. It was identified that policy returns, policy facilities, and policy technology were the most important criteria. Additionally, a performance evaluation of renewable energy investment alternatives was made with a fuzzy TOPSIS approach based on interval type-2 fuzzy sets. It was concluded that wind and solar are the most significant renewable energy investment alternatives. Therefore, it is recommended that there should be government supports for wind and solar energy investments. Within this context, corporate tax discounts for these companies, customs duty decrease for the items used in the investments, and providing qualified personnel in this area can attract the attention of these investors.