Large-scale solar energy projects are critical to India's renewable energy goals, yet their local socio-ecological impacts, particularly those developed under regulatory exemptions, are not well understood. This study provides a comprehensive, retrospective assessment of the environmental, social, and economic impacts of the 2,050 MW Pavagada Solar Park in Karnataka, India, which was established without a mandatory Environmental Impact Assessment (EIA). Using a mixed-methods approach, we collected data through environmental measurements, 100 stakeholder surveys, and focus group discussions across five affected villages. Our findings reveal significant negative impacts. Environmentally, we documented a 15% decline in groundwater levels, a 22% reduction in bee populations, and a 2°C localised temperature increase, threatening water security and agricultural productivity. Socio-economically, the land-lease model has created significant disparities; while 70% of landowners reported satisfaction with lease income, 80% of landless labourers and 90% of landless women reported income loss. Furthermore, only 15% of local households benefited from direct employment. These findings demonstrate that in the absence of regulatory oversight, large-scale solar projects can create profound socio-ecological trade-offs, undermining local sustainability. We conclude with a set of actionable policy and management recommendations, including the adoption of water-efficient technologies, equitable benefit-sharing mechanisms, and habitat restoration programs, to better align renewable energy development with environmental justice and sustainable community outcomes.