Enhanced distilled water productivity using an innovative semi-cylindrical tent-shaped solar still coupled with evacuated tubes

• Semi-cylindrical basin with evacuated tubes fabricated to hold 100 liters of saltwater. • Tent-shaped glass cover used for the solar still. • Tent shape provides two main glass surfaces with varying condensation temperatures. • Maximum daily production reached 9.7 liters/day of distilled water. • Overall thermal efficiency at 30.9 % and exergy efficiency at 5.7 % due to evacuated tubes. Despite advances in enhancing the output of conventional solar stills, the pursuit of the most efficient solar distillation technique remains ongoing. Evacuated tubes, known for their superior thermal capacity compared to traditional single-basin solar stills, offer a promising solution for high-yield distillation. This study evaluates the performance of a semi-cylindrical tent-shaped solar still coupled with evacuated tubes (SCTSCET) against a conventional single-basin, single-slope solar still, used as a benchmark. Experiments conducted in Amman, Jordan, in May 2023, demonstrate that the SCTSCET significantly outperforms the conventional solar still in distilled water production. The SCTSCET achieved a daily yield of up to 9.7 liters, which is approximately 288 % higher than the 2.5 liters produced by the conventional still. This increased productivity is due to a 45.7 % enhancement in heat capacity provided by the evacuated tubes, which raised the water basin temperature to 61.4 °C, compared to 41.2 °C in the conventional still. This higher temperature facilitated a faster evaporation rate and improved water output. Additionally, the SCTSCET exhibited a 10 % higher hourly thermal efficiency and a peak exergy efficiency of 5.7 %, compared to 3.4 % for the conventional still, highlighting its superior ability to harness and utilize solar energy for distillation.