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The work presented in this paper shows the feasibility of an innovative stand-alone solar cooker (hotplate) powered by renewable photovoltaic (PV) energy. This cooker is formed by PV panels (600 W), two DC/DC energy converters, two thermal resistors and a digital control unit. The role of the latter is to manage locally and remotely the operation of the cooker, according to the needs of the users, and to acquire and display the meteorological (lighting and ambient temperature), thermal (temperature of the resistance) and electrical quantities of the system (currents, voltages, powers, yields …). Experimentation of the system during whole days shows that, for an illumination intensity of 1115 W/m2 and an ambient temperature of about 22 °C, the global electrical power supplied by the PV panels reaches 464 W/peak. The temperature of the thermal resistance reaches 700 °C (70 °C/s) after 10 s, the efficiency of the converters is 87%, the boiling of one liter of water (temperature 90 °C) and the heating of 0.5 L of oil (temperature 270 °C) took place after 20 min. and 60 min respectively. In addition, the study on energy storage in solar batteries shows that the energy produced throughout the day can be stored in 160 Ah batteries (i.e. two 75 Ah batteries). All these results show the feasibility of the proposed cooker, and consequently its use in rural as well as urban households for cooking during sunny days and nights.

In this paper, we present the structure, the simulation the operation of a multi-stage, hybrid solar desalination system (MSDH), powered by thermal and photovoltaic (PV) (MSDH) energy. The MSDH system consists of a lower basin, eight horizontal stages, a field of four flat thermal collectors with a total area of 8.4 m2, 3 Kw PV panels and solar batteries. During the day the system is heated by thermal energy, and at night by heating resistors, powered by solar batteries. These batteries are charged by the photovoltaic panels during the day. More specifically, during the day and at night, we analyse the temperature of the stages and the production of distilled water according to the solar irradiation intensity and the electric heating power, supplied by the solar batteries. The simulations were carried out in the meteorological conditions of the winter month (February 2020), presenting intensities of irradiance and ambient temperature reaching 824 W/m2 and 23 °C respectively. The results obtained show that during the day the system is heated by the thermal collectors, the temperature of the stages and the quantity of water produced reach 80 °C and 30 Kg respectively. At night, from 6p.m. the system is heated by the electric energy stored in the batteries, the temperature of the stages and the quantity of water produced reach respectively 90 °C and 104 Kg for an electric heating power of 2 Kw. Moreover, when the electric power varies from 1 Kw to 3 Kw the quantity of water produced varies from 92 Kg to 134 Kg. The analysis of these results and their comparison with conventional solar thermal desalination systems shows a clear improvement both in the heating of the stages, by 10%, and in the quantity of water produced by a factor of 3.

Bismuth thin films were prepared on a glass substrate pre-coated with transparent and conducting layers of Tin doped indium oxide (ITO), kept at room temperature, by electrodeposition technique, using a an aqueous solution of nitric acid with a molar concentration of 1 mol L−1 and Bi(NO3)3, 5H2O as a source of bismuth. The cyclic voltammetry and chronoamperometry measurements revealed that the electrodeposition of bismuth (Bi) has been performed at a negative potential around −0.17 V versus SCE (Saturated Calomel Electrode). Moreover, the measured current transient curves were compared to those calculated from Scharifker-Hills and Heerman-Tarallo models. It was found that instantaneous 3D nucleation mechanism governs the nucleation and the growth of Bi on ITO substrate. Using these models we were able to calculate meaningful values for the kinetic parameters of bismuth growth. The characterization of samples was carried out by X-Ray diffraction and UV–Visible spectroscopy. Results showed that all the films were polycrystalline type rhombohedral crystal structure. The preferred orientation of the crystallites is (0 1 2) direction. These films exhibited also a transmittance value of about 40% in the visible range.

In this paper, we modeled the heating of thermal resistors photovoltaic solar energy. From the thermal models governing the thermal operation of the heating resistors and measuring equipment developed, we have shown, on the one hand, a very good agreement between experience and simulation, and, on the other hand, under a solar radiation of 800 W / m2, electrical power of the order 144 W and ambient temperature of 35 °C, that temperatures and thermal efficiencies of the resistors reach 600 °C and 72%, respectively. All the obtained results show the good operation of the heating resistors with the electrical energy supplied by the photovoltaic panels. Therefore, there is a possibility of using these resistors in the appropriate applications requiring heating at high temperature (> 100 °C) (Solar oven and drying,…).