Experimental determination of the standardised power of a solar funnel cooker for low sun elevations

Over the past few decades, many efficient solar cooker designs have evolved. It is important to measure their performance and communicate this information to researchers, manufacturers and users around the world. Funnel type solar cookers are simple, effective and have multiple advantages in practical use, but there is limited experimental data about them in the academic literature. This work provides performance data for a well-known design of funnel cooker. When possible, the experimental protocol was based on the ASAE S580.1 Standard. The following procedures were added to improve the quality and reliability of the measured data: i) two identical funnel cookers were tested simultaneously, side by side, to control for weather variables, ii) a large number of observations were made iii) confidence and prediction intervals were calculated for the main figures of merit iv) cooled water was used to extend the range of valid observations. Tests were conducted in Malaga, Spain, at latitude 36.9° N, between November 2019, and February 2020, a period with low sun elevation. Azimuthal solar tracking was applied. Two different pot lids were compared to investigate their influence on the standardised cooker power obtained.