The Tunisian energy sector, heavily reliant on fossil fuels, faces challenges of increasing consumption and limited resources. Committed to the 2015 Paris Climate Agreement, Tunisia aims to reduce greenhouse gas emissions by expanding renewable energy projects, particularly through the Tunisian Solar Plan. The Massire project addresses policy barriers in the Kebili region, where solar panels are used for groundwater pumping. This paper uses a water-energy-ecosystems nexus approach and SWOT analysis to develop policies and regulations for sustainable solar irrigation investments, identifying current challenges and strategies for successful energy transition.