This study aims to identify appropriate innovative strategies for solar energy investments for both commercial and non-commercial users. For this purpose, TRIZ-based 8 different innovative strategies are identified. Later, these strategies are weighted with the interval type-2 fuzzy DEMATEL (IT2 FDEMATEL) method to define more important strategies. Thus, the main motivation of this study is to figure out the weights of the strategies for solar energy investments The findings indicate that the replacement of mechanical system is found as the most effective TRIZ-based investment strategy for solar energy projects regarding both commercial and non-commercial customers. Thus, it is recommended that solar energy companies should give special support to their customers with respect to the security issues. Moreover, local quality is another significant strategy for commercial users. Therefore, it will be appropriate to provide special services according to the characteristics of the customers. Within this framework, having distribution centers close to customers and employing customer representatives who know well the culture of that region can be very helpful. Additionally, cushion in advance is found as another appropriate TRIZ-based innovative strategy for commercial customers. Hence, it would be appropriate to ensure the security in solar panels. Within this context, necessary measures should be taken for problems such as electric shock, material destruction, theft, and risk of destroying data on the computer.