This document summarizes an experimental investigation of a double slope solar still with a latent heat storage medium. Key findings include:
1) Adding zinc nitrate hexahydrate, a phase change material, to the still's basin increased total daily distillate output by 33.5% compared to the still without PCM.
2) The glass covers of the still with PCM maintained higher temperatures than without PCM, especially in the afternoon, due to the thermal inertia of the PCM tubes.
3) Hourly output measurements found 34.7% higher daytime production and 31.7% higher nocturnal production with the PCM, demonstrating its ability to continue providing thermal energy after sunset