Designing and testing low-cost solar water heater using date palm fibers and starch

Solar water heaters are a type of renewable energy technology that converts solar energy into heat to warm water. Solar water heaters are becoming increasingly popular due to their eco-friendliness, cost-effectiveness, and low maintenance requirements. In this study, low-cost solar collectors were developed using date palm waste (dried leaves) as thermal insulation. Date palm waste is a readily available and abundant resource in many regions, and using it in solar collectors can help reduce waste and promote sustainability. Two solar collectors were fabricated using crushed date palm waste, with one collector using the waste alone and the other mixed with starch. Tests were conducted in accordance with the European standard EN 12975-2-2006 and modeled the thermal behavior of the collectors. The results obtained showed that the prototypes of solar collectors performed well and exhibited behavior comparable to that of a commercial solar collector, with a production cost up to three times less. The use of date palm waste as thermal insulation in solar collectors is an innovative approach that aligns with the principles of sustainability and environmental friendliness. Furthermore, it was found that the leveled heating cost (LCOH) and the simple payback period (SPP) were 0.952 US$ kWh^-1 and 2.472 years for the prototype without starch and 0.926 US$ kWh^-1 and 2.397 years for the prototype with starch.