Low-maintenance Solar-hydrogen Generator Using Alkaline Water Electrolysis

Hydrogen generated using solar energy shown to be a promising renewable energy source specifically for transportation systems. Preferred method to generate hydrogen from solar-energy is alkaline water electrolysis AWE. However, current AWE is usually associated with high-maintenance: kgs of electrolyte needed; kwh of energy consumed; and high corrosion on electrodes due to high operating temperatures. Low maintenance is essential for this technique to be successful and commercially viable. This paper addresses some of these concerns. In this paper we outlined the solutions for a specific test case so we have some specific numbers to compare. The test case here is to generate a kg of hydrogen to drive a car for an average commuting distance of 50 km in one solar day. Here we derived an optimal set of cell operating conditions for minimal maintenance. The data for this study we took it from our earlier study where we conducted an exhaustive set of AWE-experiments to gather measurement data. This data is then used to generate corresponding normalized AWE hydrogen generation production charts. Input variables for the production charts include varying: electrolyte concentrations, voltages, number of cells, and their cell areas. Measured output variables include: time required per liter of hydrogen generation, temperature rises, and currents drawn. The generated cell production charts include: production rate charts; energy consumption charts; and overall cell conversion efficiency charts. From these production charts we arrived at optimal operating settings that require minimal maintenance. We are able to achieve substantial reduction in all of the above three areas of maintenance.