This article synthesizes review-level scholarship on renewable energy certificates (RECs) and adjacent energy-attribute instruments as a preliminary stage of a broader systematic literature review (SLR) focused on I-RECs and related certificate markets. The corpus was drawn from review records identified during the screening workflow of a wider REC-centered SLR protocol, aligned with PRISMA 2020 guidelines. Following deduplication and relevance screening, twelve substantive reviews were retained for synthesis. These reviews were classified into three analytical groups: comprehensive reviews, single-topic reviews, and tracking-technology reviews.
The article addresses six research questions: (RQ1) the mechanisms employed to develop RECs; (RQ2) whether RECs contribute to investment in renewable generation and storage; (RQ3) how regulatory frameworks and policy designs shape certificate effectiveness; (RQ4) which technologies are used to prevent double counting; (RQ5) which business models and market actors generate RECs; and (RQ6) what principal gaps remain in the review literature.
The findings reveal that the review field is heterogeneous and remains conceptually fragmented. A recurring pattern is that certificate systems do not function in isolation; rather, they are typically embedded in broader policy mixes that include renewable portfolio standards, feed-in tariffs, carbon markets, green power trading, disclosure systems, and corporate accounting standards. Evidence on investment effects is suggestive but uneven and tends to be strongest when certificates are tied to scarcity, clear retirement rules, credible registries, and demand from compliance obligations or premium voluntary buyers. The literature further indicates that double-counting prevention depends less on the certificate label itself than on governance architecture—encompassing registry design, issuance controls, retirement procedures, residual-mix treatment, and, increasingly, digital traceability infrastructure. Brazil is represented in the review literature as a rapidly maturing voluntary market, particularly through the articulation between I-REC/I-TRACK architecture, REC Brazil sustainability attributes, and more recent institutional innovations such as the CCEE certification platform. Significant gaps nonetheless persist, most notably with respect to causal evidence on additionality, storage incentives, and cross-country comparability. The article concludes that this review clarifies the conceptual terrain, refines the coding logic for the forthcoming SLR, and identifies a more rigorous agenda for future research.