Experimental characterization of a panel solar cooker with adjustable geometry for sun tracking

This study experimentally analyzed the performance of a panel solar cooker with a variable geometry for proper sun tracking. Its peculiarity is that, unlike many other panel cookers, the geometry can be adjusted during days, seasons, and at different latitudes to maximize the amount of solar radiation concentrated on the receiver. To study the impact of sun tracking, several tests without and with load (water and glycerin) were performed by adjusting the device geometry considering different time intervals. The tests with water showed that the device usually brought 1 kg of water from 40 to 90 °C in about an hour, proving its good thermal performance. Instead, the tests with load with different sun tracking showed that the performance of the device adjusted every hour was slightly lower than that of the prototype adjusted every 15 min. This proves the device ensures good performance even when oriented every hour. In addition, various receiver configurations were tested, finding that the receivers comprising black pots within different glass bowls ensured rather similar results. In contrast, as expected, the receiver with a plastic enclosure had lower performance but still brought the water temperature from 40 to 90 °C in less than two hours. Finally, the performance parameters of the proposed prototype were compared with those of panel cookers available in the literature. It was found that the parameters of the presented solar cooker are consistent with the values reported in previous studies.