Abstract—Islanded and remote power systems in Sri Lanka’s Northern region faces challenges in maintaining reliable electricity supply while transitioning toward higher shares of renewable energy. Solar Photovoltaic (PV) and wind resources represent promising alternatives; however, their inherent intermittency require careful evaluation of resource complementarity to enhance system stability and reduce storage dependency. This study investigates the temporal complementarity between solar and wind resources in selected Northern islands of Sri Lanka using hourly generation data. Three complementary assessment metrics are employed: the Pearson correlation coefficient (r), the Complementarity Index (CI), and Cross-Correlation Function (CCF) analysis. The analysis is conducted at annual and seasonal scales where the latter further divided into four monsoon periods to capture climatic influences specific to the region. Results indicate weak to moderate negative correlation during key monsoon periods, suggesting beneficial complementarity between the two resources. The Complementarity Index further confirms seasonal smoothing effects, while cross-correlation analysis reveals time-lag interactions that can be exploited for improved hybrid system scheduling. The findings demonstrate that integrating solar PV and wind generation can significantly enhance supply reliability for islanded systems in Northern Sri Lanka. The study provides quantitative insights to support optimal hybrid system planning and future renewable energy deployment strategies in monsoondominated regions.

Keywords—hybrid renewable energy systems, island electrification, resource complementarity, solar energy, wind energy

Cite: Anuththara Ariyarathne, "Implications of Solar–Wind Resource Complementarity for Hybrid Renewable Systems in Northern Islands, Sri Lanka," International Journal of Smart Grid and Clean Energy, Vol. 15, No. 1, pp. 31-44, 2026. doi: 10.12720/sgce.15.1.31-44

Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).