Potential and economic viability of green hydrogen production by water electrolysis using wind energy resources in South Africa

Abstract

In recent times, more attention is given to renewable and clean energy sources that could ameliorate the current shortage of electricity plaguing South Africa. Due to the comparable use of hydrogen to fossil fuel in the transportation, industrial and electricity sector, hydrogen could be a potential solution to the current energy crises especially when produced from a clean and sustainable source. One of the most appropriate methods of green hydrogen production is the use of wind energy via water electrolysis. This paper therefore investigates the capability and viability of hydrogen production from the wind energy resources of South Africa using the actual wind speed obtained at 60 m anemometer height. Sensitivity analyses are also conducted to gain insight into the possible influences of wind turbine operating parameters on the cost of hydrogen production. Wind regime of fifteen (15) different sites across five (5) major provinces are analysed for possible wind-hydrogen production using eleven (11) different off-the-shelf wind turbines ranging from small to large categories. Some of the key results revealed that the mean wind speed (Vm) varies from 5.07 m/s in Eston (S12) to 8.10 m/s in Napier (S5). Wind turbine WT9 (ServionSE MM100) with rated wind power of 2 MW, cut-in wind speed of 2 m/s, rated wind speed of 11 m/s, cut-out wind speed of 22 m/s and turbine hub-height of 100 m has the highest capacity factor (Cf) across all the sites with the values that range from 24.04% in Eston (S12) to 54.55% in Napier. Site S5 presents the best hydrogen production potential with annual hydrogen production that ranges between 6.51 metric-tons with turbine WT1 and 226.82 metric-tons of hydrogen with turbine WT11. Wind turbine WT9 has the least cost of electricity generation ranging from 0.23$/kwh at site S5 to 0.42 $/kwh at site S13. Also, the cost of hydrogen is lowest at site S5 and ranges between 39.55 $/kg using wind turbine WT1 and 1.4 $/kg using wind turbine WT11. The sensitivity analysis conducted revealed that rated wind speed has significant effect on the cost of hydrogen production compared to other wind turbine parameters.