AHP is the most popular multi-criteria decision-making (MCDM) method to prioritize the evaluation criteria and to rank the considered alternatives. TOPSIS method is another often used MCDM method based on negative and positive ideal solutions for the selection of the best alternative. Although the picture fuzzy extensions of the TOPSIS method are used to consider experts’ hesitancy and refusal degrees in their judgments, there is a need to add reliability degrees to these judgments to provide better solutions and a reliable decision environment for real-life decision problems. This study presents a decision support tool that integrates the picture fuzzy Z-AHP (PF Z-AHP) method based on pairwise comparisons and a novel PF Z-TOPSIS method which includes reliability information for ranking the alternatives. The proposed PF Z-AHP&TOPSIS methodology is applied for solar energy panel selection problem to analyze the practicality and superiority of the methodology. The sensitivity analysis demonstrates the robustness of the proposed methodology, and the comparison analysis presents evidence that the reliability functions offered by Z-numbers have the potential to affect outcomes.