Seawater desalination provides an effective means to address water scarcity intensified by global warming and rising demand. When powered by solar energy, it can supply freshwater with minimal CO 2 emissions. This study develops and compares two fully solar-powered desalination systems, using modeling and simulations, aimed at increasing the Recovery Ratio (RR) and valorizing brine from a Reverse Osmosis (RO) unit. Both systems integrate thermal and electrical energy storage and incorporate Membrane Distillation (MD) units operating in series with RO. System A uses photovoltaic (PV) panels and solar thermal (ST) collectors, while System B combines hybrid photovoltaic/thermal (PV/T) panels with ST collectors. Simulations are performed under real meteorological conditions over one year in Almería, Spain. No previous work has assessed the techno-economic performance of solar-powered hybrid desalination systems with energy storage for higher RRs, nor compared traditional and hybrid solar collectors through dynamic annual simulations. The RO–MD configuration enhances RR and freshwater production relative to RO alone. System A increases output by 9.22%, and System B by 8.60%. RR rises from 40.50% to 44.23% in System A and from 42.04% to 45.66% in System B. PV/T integration in System B further improves performance by preheating seawater, reducing specific energy consumption (SEC), and increasing PV efficiency. This results in an 8.93% production gain and a 3.24% RR increase over System A. Levelized Cost of Water (LCOW) values are 5.01 and 5.27 USD/m 3 for Systems B and A, respectively, higher than conventional water costs but lower than many reported for solar-powered desalination systems. • Placing MD plants in series with a RO unit enhances overall freshwater production and increases the RR. • The solar‑powered RO‑MD system with energy storage achieves a lower LCOW than other solar‑powered desalination options. • A hybrid PV/T collector in an RO‑MD system enables higher freshwater output than a standard PV collector. • A hybrid PV/T collector in an RO‑MD system yields a lower LCOW than a conventional photovoltaic collector.

• Six robust solar cookers made of concrete were tested side by side. • Four were equipped with good-quality mirrors, while two had degraded mirrors. • An enhanced performance evaluation method was adopted. • Non linear curves for efficiency and performance data were determined. • Additional tests were conducted to assess the reproducibility of results. The Pucca solar cooker is a domestic funnel-type cooker, constructed of concrete and silvered glass mirrors. Its robust construction allows it to be kept outside permanently, in all weather conditions. However, its reflectors may gradually degrade over time, leading to diminished performance. To assess this issue, six Pucca cookers were tested side by side using a water load of 2 kg in each cooker. Two of the cookers had new mirrors, two had minimally degraded mirrors, and two had badly degraded mirrors. Non-linear efficiency curves were determined by a suitable enhanced evaluation method. Small differences were noted between the efficiency curves of the four cookers with the least degraded reflectors. By contrast, the points of maximum efficiency for the two cookers with badly degraded reflectors amounted to only about 70% of the value seen in the other cookers. The impact of this degradation on performance is illustrated by the figures predicted using the enhanced procedure, where the measured temperature data were fitted to a second-order polynomial with a time-dependent exponential term to derive nonlinear efficiency curves. The best performing cooker is expected to boil 2 kg of water in about three hours when the ambient temperature is 20 °C and the solar irradiance is 700 Wm −2 , and in only 1.4 h when the ambient temperature is 30 °C and solar irradiance is 1000 Wm −2 . The two cookers with badly degraded mirrors could not boil 2 kg of water at all under either of those conditions. The enhanced method is reliable.