3ème Partie PRESENTATIONS THEORIQUES
de la cuisson solaire photovoltaique
avec des résistances céramiques PTC

Trois documents de présentation théorique sont disponibles :
- Une présentation vidéo
- Un compte rendu de Congrès
- Un article de la revue Energies

1- Une présentation video
Une présentation théorique par vidéo (différente de la video de présentation générale) a été réalisée à l’occasion du congrès de cuisine solaire CONsolFOOD en Juillet 2023 à La Corogne en Espagne. Elle est disponible ici

2- Un compte rendu
La communication présentée à ce congrès a fait l'objet d'un document d'une dizaine de pages publié dans les proceedings du congrès, disponible ici, pages 32 à 41 , et dont voici l'abstract:

Due to the continuous decrease in the price of photovoltaic solar panels, it is now possible to use them to produce heat, for example, for cooking, allowing indoor kitchens. But it is still necessary to have a regulated electrical current. We propose using PTC (Positive Thermal Coefficient) ceramic resistors, whose flexibility of operation adapts well to the variations of photovoltaic electricity and avoids overheating. In some PTCs, the resistance increases sharply above ≈200°C (Curie temperature); thus, the heat production stagnates. Therefore, there cannot be any burnout or overheating. A solar cooker has been conceived using them without them. This allows a solar cooker without electronics or batteries. The regulation of the cooker consists of putting into operation the appropriate number of ceramics according to the sunshine and the power required. This is feasible with the help of a Wattmeter, which guides the user in finding the best point of heat production. Since the temperature external to the resistors and pot is always below 200°C, it is possible to thermally insulate the cooker and the cooking vessel completely with ordinary materials. Thermal insulation significantly increases the installation's energy efficiency during the heating and slows the following cooling process in retained-heat slow cooking. The paper offers the design principles, implementation, and test results. It offers information to replicate and pave the way to improve this photovoltaic solar cooker.

3- Un article
Un article a été publié dans la revue Energies en Mars 2024 sous le titre
Solar Photovoltaic Cooker with No Electronics or Battery, as part of the Special Issue Photovoltaic/Thermal Systems: Advances and Contribution to the Development of Renewable Energy Communities .
Il est disponible ici, gratuitement.
En voici l'abstract :

The paper offers innovative cooking utensil designs for remote, isolated, and even peri- urban communities at a low price, with high reliability and simple construction. It can alleviate energy poverty and improve food security. This utensil uses only local solar energy directly and allows comfortable indoor cooking. This paper provides the design principles of a solar cooker/frying pan or generic heater, based on a PV panel or a plurality of them, which are directly connected to a plurality of Positive Thermal Coefficient (PTC) resistors to match the power. PTCs are nowadays produced in massive quantities and are widely available at low cost. The proposed device does not require an electronic controller or a battery for its operation. The aim is for family use, although the design can be easily scaled to a larger size or power, maintaining its simplicity. Electric heating inside or attached to the cooking pot, plus the temperature self-limiting effect of PTCs, allows for thermally insulating the cooking pot from its outside using ordinary materials. Insulation enhances energy efficiency during cooking and keeps cooked food warm for a long time. Clean development would receive a significant impulse with its application. A simple mathematical model describes its functioning and states guidelines for adequate design. Its results indicate a successful proof of concept and high efficiency both for water and oil as representatives of cooking.