Photovoltaic technology as a tool for ecosystem recovery: A case study for the Mar Menor coastal lagoon

A wide range of environmental impacts have been triggered worldwide by intensive agrarian production designed to maximize crop yields. The ecological crisis in the Mar Menor, Europe's largest salt-water lagoon, is an example of how changes in traditional farming practices have had a significant impact on the lagoon ecosystem. In this context, integrated photovoltaic systems can potentially alleviate the pressure for land resources while also contributing to sustainable land use and reducing eutrophication in the lagoon. The case study is an example of balance between two United Nations Sustainable Development Goals (SDGs): Zero hunger (SDG 2) and Affordable and Clean Energy (SDG 7) achieved by sharing land occupation and additionally obtaining an ecosystem restoration, linked to SDGs 6 (Clean Water and Sanitation) and 13 (Climate Action). Based on official information and literature studies on watering, fertilizing needs, and production, we developed an approach for combining geographical data with estimates of the environmental benefits of photovoltaic integrated solutions. The results show that up to 1377 tonnes/year of nitrate fertilizer can be avoided, and water use can be reduced by up to 27 Hm3/year, depending on the distributed photovoltaic power scenario selected. Likewise, the installed capacity of ground-mounted, agrivoltaic, greenhouse-mounted, and floating photovoltaic systems varies from 54 GWp, 16 GWp, 0.4 GWp, and 0.6 GWp, respectively.