A mixed-methods evaluation of substitution fee design in White Certificate Systems: Evidence from Poland
Substitution fees (SFs) are integral to White Certificate Systems (WCS), providing a flexible compliance mechanism that links financial contributions with energy efficiency objectives. Empirical evidence on SFs remains limited, particularly regarding their integration into WCS design and their capacity to drive sustainable energy transitions. This study systematically evaluates SF design, implementation, and performance, with emphasis on their role in achieving policy targets and maintaining market stability. Using a mixed-methods approach—comprising a literature review, stakeholder workshop, and expert survey assessing nine SF models against ten weighted criteria—the analysis identifies the need for robust monitoring, transparent rate-setting, and equitable designs adapted to sectoral diversity. Poland’s WCS serves as a central case, illustrating the risks of arbitrarily set SF rates and limited data transparency, which undermine market efficiency. Findings highlight the value of reinvesting SF revenues in energy efficiency, innovation, and energy-poverty mitigation. Among the models assessed, the Dynamic SF Model is most promising, offering adaptive adjustments to market and technology trends while sustaining stability. Continuous evaluation and integration with emerging technologies are essential to align SF frameworks with evolving regulations and global decarbonization goals.