Enhancing Freshwater Productivity of a Single Slope Solar Still Using Heat Induction from a Photovoltaics-Thermal System

This study reports the development and performance evaluation of a coconut-shell-charcoal-based photovoltaic–thermal (PVT) system integrated with a single-slope solar still (SSSS) to improve freshwater productivity while generating electricity. The PVT system performed a dual role: producing electrical power and recovering waste heat for thermal induction, with the charcoal encapsulation serving as a thermal absorber and storage medium. A monocrystalline PVT unit was experimentally tested in Manado, Indonesia, where key parameters (including solar irradiance, ambient humidity, wind speed, panel surface temperatures, saline water temperature and flow rate, electrical output, and freshwater yield) were systematically measured. Results showed that although the PVT panel produced slightly lower electrical output than a conventional PV module, its overall energy utilization was superior due to efficient heat retention and transfer. When coupled with the SSSS, the system achieved an average freshwater yield of ۳.۰۴ L·m⁻²·day⁻¹ and a maximum yield of ۵.۲۰ L·m⁻²·day⁻¹, outperforming several recent single-slope solar still designs. Peak freshwater production occurred between ۱۰:۰۰ and ۱۵:۰۰ local time, aligned with maximum solar irradiance, while the highest evaporation efficiency reached ۲۰.۸%, confirming the significant role of PVT-induced heat in driving the desalination process. These findings demonstrate the potential of locally sourced biomass, particularly coconut-shell charcoal, as a cost-effective and sustainable material for hybrid solar desalination technologies. Future improvements are directed toward absorber design optimization, integration of biochar–PCM composites, and adaptive flow control strategies to further enhance long-term freshwater productivity in remote and drought-prone coastal regions.

کلیدواژه ها:

Thermal perfomance ، Electrical performance ، Evaporation efficiency ، Weather effect ، Water yield