Solar water desalination represents a sustainable pathway for freshwater production in water-scarce arid and semi-arid regions; yet, conventional solar stills suffer from inherently low productivity due to limited absorber-water contact and inefficient energy conversion. In order to address this issue, we propose an innovative solar still absorber design that expands the contact surface by 125.44% through finned basin partitioning to enhance the solar energy conversion into heat. A rigorous 4E analysis (energy, exergy, environmental, and economic) was conducted on two experimental prototypes operating under identical meteorological conditions, with comprehensive computational fluid dynamics (CFD) validation. Results demonstrate that the multibasin absorber enhances solar energy conversion by raising water temperature by approximately 7%, leading to a freshwater yield of 3.04 L/m(2) on April 20, and a 31% improvement over the conventional configuration. The 4E analysis reveals a 9% improvement in energy efficiency and a 2.7% enhancement in exergy with the novel absorber design, compared to the conventional one. Additionally, an environmental and economic analysis indicates a 14% cost reduction compared to traditional solar still configurations. Using the VOF multiphase flow, k-epsilon RNG turbulence, and DO radiation, the CFD model demonstrates a good agreement with experiments with a maximum water-temperature deviation not exceeding 3 degrees C ( approximate to 4% relative error), confirming its prediction capability under various climatic conditions.