Techno-economic analysis of an off-grid micro-hydrokinetic river system for remote rural electrification

Published ArticleThis study investigates the use of off-grid micro-hydrokinetic river system as a cost-effective and sustainable electricity supply option for remote rural residents in close proximity to flowing water and not having access to grid electricity. This hydrokinetic technology is still in the development stage and there is a lack of application especially in rural areas with reasonable water resource. This study will present the economic and environmental benefits of the proposed system. A mathematical model is developed to simulate the system performance as submitted to different solicitations. A test prototype will also be used in order to validate the simulation results

Grid-interactive micro-hydrokinetic with pumped-hydro storage: The case study of three South African demand sectors

Conference ProceedingsThis paper investigates the operation of different demand sector such as residential, commercial and industrial load profiles when supplied with a grid tied micro-hydrokinetic pumped-hydro storage (MHK-PHS) hybrid system. The aim is to explore the demand sector which is more favorable to the proposed grid-tied MHK-PHS hybrid system under the time-of-use (TOU) tariff scheme. Hence, the optimum configuration of the proposed MHK-PHS hybrid system is determined in order to investigate the effect of each demand sector on sizing and operation of the hybrid system. HOMER Pro Version 3.6.1 has been used to perform the optimization under TOU tariff scheme. The results have shown that the industrial load sector incur the lowest cost of energy at the highest capital cost as opposed to the residential and commercial load sectors. However, from economic perspective, the residential demand sector proved to be more favorable to the proposed hybrid system due to the lowest net present cost (NPV). For each load demand sector, HOMER led to oversizing constraint of the hybrid system by not recharging the storage system after use

IMPACT OF DIFFERENT LOAD PROFILES ON SIZING AND PERFORMANCE OF A MICRO-HYDROKINETIC-BATTERY BASED HYBRID SYSTEM

Conference ProceedingsHydrokinetic hybrid systems are gaining more interest since hydrokinetic technology has proved to offer a cost-effective electrification solution. Very few research studies on sizing and optimization of micro-hydrokinetic-battery (MHK-B) based hybrid systems have been done. However, the authors did not explore the impact of different load profiles on optimal sizing and performance of the MHK-B hybrid system. In this study, the impact brought by different load profiles such as residential, commercial and industrial sectors on sizing and operation of a river based MHK-B hybrid system is investigated using Hybrid Optimization Model for Electric Renewable (HOMER) software. HOMER Pro version 3.6.1 has been selected since it is equipped with hydrokinetic turbine module. The flowing water resource data obtained from a typical river of South Africa has been used as an input. Sample of load profile curves for residential, commercial, industrial have been used to estimate the daily load demands. The optimum configuration results indicated that for the same daily energy consumption, the type of a load profile affects the battery storage capacity, hydrokinetic turbine size, inverter and rectifier operational hours as well as the annual excess energy for the MHK-B hybrid system

Simulations and experimental validation of Pico conduit pressure hydropower systems with battery storage

ArticleAn increase in the world's population has led to an increased energy demand. Sustainable renewable energy sources must be broadly executed to fulfil the continuous need for energy. Amongst different renewable energy technologies, hydropower generation proved to be the most feasible solution. A portion of small hydropower can be acquired by recovering the energy inside water supply networks. This may lead to a sustainable electrification solution and reduced electricity bills for the water utility companies. Hence, the procedure of energy recovery using conduit hydro technology must be a part of the water cycle. Numerous nations have started with the improvement of this innovative conduit hydro technology. However, very little has been exploited. Hence, this study focuses on developing a simulation tool that can be used to analyse conduit hydropower generation system with a battery storage. Subsequently, this paper exhibits the modelling and performance analysis of a small conduit hydropower system in MATLAB/Simulink software. This will assist the conduit hydropower developers to quantify the available energy and evaluate the viability of the conduit hydropower projects. Furthermore, the performance of the modelled conduit hydropower system is compared to the performance of a prototype setup in a laboratory environment. Inlet water pressure was assessed to observe how the system reacts to the variation of the water pressure. This data was used to simulate the performance of the model in MATLAB/Simulink in comparison with the laboratory prototype. The results revealed that the developed model reacted viably under variable pressure. The conduit hydropower was just dynamic when the excess pressure was accessible, this is because of the pressure distinction between Pressure Reducing Valve (PRV) pre-set pressure and the system pressure. Hence, the excess pressure is used to drive the generator and the generated energy is then stored in the battery

Energy flow modeling between grid and micro-hydrokinetic-pumped hydro storage hybrid system

Conference ProceedingsThis paper proposes an optimal energy management model for a grid-connected micro-hydrokinetic pumped hydro storage (MHK-PHS) hybrid system supplying the commercial load. The aim of the model is to minimize the energy costs through power-flow control variables and time-of-use (TOU) tariff scheme. The optimization problem will be solved through the use of the linprog solver in the MATLAB’s optimization toolbox for 216 hours as a means of including the weekend as well. The simulation results show that the developed model can assist the onsite MHK-PHS hybrid system to optimally reduce the electricity consumption cost of the commercial load. Additionally, Sundays have proved to lead to concurrent use of all power sources for the entire business hours of the commercial load

Modelling and simulation of a hydropower system using wastewater discharged from Marine outfalls

Municipal or industrial wastewater from the treatment plant is discharge by marine outfalls through the use of a pressurized pipeline scheme. The wastewater is discharged deep under the sea surface at a distance from the coast. During discharging of the wastewater, the excess pressure is applied to push the wastewater deep under the sea. The operation of allowing the wastewater to be discharge far away from the coast, takes the environmental perspective into consideration. However, from engineering perspective, significant amount of energy is wasted during discharging of wastewater and can be recovered. Hence, the aim of this paper is to model and simulate an energy recovery system able recover some of the energy wasted, using a hydro-turbine and generator in a hydropower scheme. The simulation results, for the South African Green Point outfall, have demonstrated that the marine outfalls have the potential to generate electrical energy during discharging of the wastewater. Using a 16-kW permanent magnet synchronous generator, the load demand of a 16 kW resistive load was met at a nominal voltage of 313 Vrms. Given the constant discharge flowrate of 28.4 × 106 litres of wastewater per day at Green Point outfall site, a significant amount of electrical energy can be generated