ElectroSphere: Electrical Electronics Engineering Bulletin
Water Quality Effects on PEM Electrolyzer Performance:Short-Term Comparative Assessment of Four Common Sources
Abstract
Emmanuel Akono Sarsah and Abdul-Rahim Bawa
Water quality requirements are a major barrier to proton exchange membrane (PEM) electrolyser deployment in settings where ultra-pure water is costly or unavailable. This study evaluates a small-scale PEM electrolyser operated with four commonly accessible water sources: distilled water, municipal tap water, packaged sachet water and borehole water. For each water type, three repeated tests were conducted and hydrogen production time, specific energy consumption (SEC) and electrical characteristics were measured under identical operating conditions. In addition, the physicochemical properties of the water sources, including electrical conductivity, total dissolved solids, pH and major ions, were characterised to support interpretation of performance trends. Performance differences between water types were modest. Hydrogen production times ranged from 13.3 to 15 minutes (≈11% spread), SEC from 3.82 to 4.14 Wh/L (≈8%) and operating voltage from 2.06 to 2.07 V (<1%). Contrary to expectation, distilled water produced hydrogen most slowly and was not the most energy efficient. Borehole water achieved the lowest SEC (3.82 Wh/L), while all non- distilled sources produced hydrogen about 7–11% faster than distilled water, consistent with their higher measured ionic conductivity. Visual inspection showed no electrode fouling during testing. These results indicate that, in the short term, non-ideal but readily available water sources such as tap and borehole water can support acceptable hydrogen production in intermittent PEM electrolyser operation. However, the short test duration, approximately one hour per water type, limits conclusions regarding long-term durability, which will require extended monitoring and ageing studies.