Techno-economic analysis of hybrid solar-biomass-wind for water pumping considering carbon tax and renewable energy rebate

Abstract

There is a need for increased penetration of renewable energy resources (RES) in the energy mix of South Africa that is currently bedevilled by recurring load shedding thus affecting sustainable critical infrastructures such as water pumping and water use. This paper assesses the viability of three RES of solar, biomass, and wind for water pumping at two locations (University of Johannesburg, APK campus – L1 and Zuikerbosch pumping station – L2) in Johannesburg, South Africa by utilising daily data from 2003 to 2020. A detailed feasibility analysis of the three RES was conducted, after which a rebate-based novel model for reducing the unit cost with zero greenhouse gas (GHG) was implemented for solar PV. Key findings reveal that the power requirement in L1 and L2 booster stations are 91 kW and 71,331 kW, respectively while the produced power from a 350 W monocrystalline PV-module utilized is 0.103 kW in L1 and L2 using 882 and 692,534 modules. The biomass power of 47.68 GW in L1 and 99.42 GW in L2 was produced from an average amount of food waste estimate of 1641 and 1248,800 tonnes evaluated from 3729 and 2838,100 tonnes of putrescible waste using a population model. The power density results depict a very weak wind energy application capability in the two locations based on National Renewable Energy Laboratory indices after using 11 differently sized wind turbines in the two locations. Finally, the result from the rebated unit-cost model reveals that the unit cost of water dropped by 17.09$/kWhr from 0.33$/kWhr in L1 and 21.20$/kWhr from 0.66$/kWhr in L2 using the solar PV modules. The study aligns with similar study done in Qatar, and the Springer report on Energy Democracy Evaluation for 100% Renewable Energy Policies and Projects showing an increased penetration of affordable and carbon-free RES which will in turn reduce climate change effects globally.