Energy Sources, Part B: Economics, Planning and Policy, cilt.21, sa.1, 2026 (SCI-Expanded, Scopus)
This study disaggregates renewable energy R&D spending into solar and wind technologies and quantifies their dynamic effects on three sustainability dimensions (CO2 emissions, load capacity factor (LCF), and the Sustainable Development Index (SDI)) in Germany, France, Denmark, and the Netherlands from January 1990 to December 2022. Monthly series are constructed using a quantile match-sum method, and the cross-quantilogram (CQ) approach is employed to capture short- and long-term, tail-specific dependencies. Key findings indicate that solar R&D induces immediate dampening effects on CO2 emissions at higher quantiles in Germany and the Netherlands, while wind R&D delivers the most pronounced long-term emission reductions in France. Both technologies drive significant gains in upper-quantile LCF, signifying enhanced ecological regeneration, and in medium-to-high SDI quantiles, reflecting sustained socio-environmental welfare improvements. By pioneering a fully disaggregated, multi-indicator CQ framework, the paper offers actionable insights for precision innovation policy: differentiated R&D portfolios and distribution-sensitive assessment schemes are critical to accelerate progress toward SDG 7 and SDG 13 and to reinforce broader sustainability objectives.