The Effect of Adding Carbon (soot) to the Paint of an Absorbing Surface in Homemade Solar Systems


Absorbing materials are key components of any solar water heater device. Silicon solar cells are very efficient but are highly expensive. An alternative is to use absorbing materials that are cheaper than silicon to produce. The use of carbon (soot) in the preparation of the coating layer of a homemade solar water heater has been investigated. When added in different proportions to oil-based white paint, marked increases in water temperatures were obtained. The increase in water temperature was directly proportional with the increase in the percentage of carbon in the coating layer. The maximum achieved outlet water temperature was 90° C in July and 70° C in November.Due to its non-toxic nature and very low cost, carbon in the form of smoke suspension or soot, can provide a good and reliable alternative in the fabrication of domestic solar water heaters.