Renewable electricity surplus exchanges through the Italy–Tunisia ELMED interconnection: an exploratory market coupling analysis

The Mediterranean region is emerging as a strategic area for energy transition, where cross-border electricity interconnections can play a key role in integrating renewable energy resources and strengthening Euro-Mediterranean cooperation. In this context, the ELMED interconnection between Italy and Tunisia serves as a significant case study for analyzing how cross-border electricity exchanges can facilitate the integration of renewable energy surpluses between power systems with different demand profiles and resource availability. This work develops a quantitative market coupling model to simulate electricity exchanges between Italy and Tunisia, focusing on renewable energy surpluses, zonal prices, gas consumption and CO₂ emissions. The analysis is carried out on a representative summer day in different scenarios of renewable (photovoltaic and wind) capacity expansion on both sides of the interconnection. The findings indicate that, under the analyzed configuration and stylized assumptions, ELMED is activated when renewable generation surplus in one country coincides with residual demand in the other, with electricity flows concentrated mainly during the middle of the day. The analysis also identifies an indicative interpolated transition value of approximately 6.16 GW of Tunisian PV capacity, corresponding to about 7.92 GW of total PV and wind capacity under the considered configuration, beyond which Tunisia shifts from being a net importer to a net exporter of renewable electricity to Italy. This transition is associated with a comparative reduction in natural gas consumption and CO₂ emissions in the importing system. Furthermore, the results suggest that, under simplified assumptions, cross-border interconnections such as ELMED can support the integration of renewable energy surpluses and reduce reliance on thermal generation when complementary production and demand conditions exist. These findings should be interpreted as exploratory outcomes of the proposed model rather than as generalizable estimates of actual system behavior. Nevertheless, this analysis highlights the potential contribution of cross-border electricity interconnections to renewable energy integration, decarbonization, and broader energy transition objectives consistent with the principles of SDG 7.