Renewable Energy Microgrids to Improve Electrification Rate in Democratic Republic of Congo: Case of Hydro, Municipal Waste and Solar

Worldwide, it is imperative for citizens to have access to electrici-ty. This applies to Congolese--rural and urban dwellers, and if possible, it should be guaranteed by government’s laws and poli-cies. However, the rural and urban areas of Democratic Republic of Congo (DRC) suffer majorly from lack of access to electricity. The major reasons are the high costs associated with connection to the national central grid and production insufficiency. There-fore, one feasible approach to electrify these areas is to use mi-crogrids. This technology is decent and viable option for energy revolution since it incorporates energy storage systems, distribut-ed generators, and localized loads. This paper has taken to im-plement this solution by firstly analysing some cities located at the borders of large rivers or watercourses (with known depth and width), such as the Congo River considered for hydrokinetic pow-er (HKP). However, where the Congo River does not pass through, the paper will consider largest rivers passing in the area. For the case of photovoltaic electricity production, large cities are considered those with good sunshine and large population who have purchasing power for the photovoltaic electricity. The waste to energy power plans will consider the top ten densely populated cities in DRC. The proposed microgrids will operate in isolation (islanded) mode. This paper proposed 44 projects to generate 795 690 kW total energy from the microgrids. These energies are divided as 661 000 kW from solar photovoltaic, 83 790 kW from waste to energy, and 50 900 kW from hydrokinetic generation. The urban share will be 94.9% and rural area share will be 5.1% of this generation. Further work needs to include biomass as a possible renewable energy to add in the mix

Improved Clamped Z-Source Converter with Optimized Maximum Power Point Tracker for Hybrid Renewable Energy Systems Based Energy Management System

In light of the intermittent and seasonal nature of wind and solar energy, electrical systems are becoming more problematic to operate. The purpose of the work is to establish an energy storage system that helps to minimize such operational challenges, which are essential to improve grid stability and reliability. The tasks solved in the article to achieve the given goal are the following: incorporating an energy management system with the aid of improved converter and optimized maximum power point (MPPT) for (Photovoltaic) PV and PMSG (permanent magnet synchronous generator) based wind system. On comparing with conventional Z-source converters, a novel improved clamped Z-source converter, which is utilized in this work has high efficiency with low THD and it has the capacity to protect electrical circuits against damage caused by short circuits, overcurrent and overvoltage. The Pulse Width Modulation (PWM) rectifier is implemented to convert AC-DC supply obtained from the PMSG wind system. Firefly optimization with an aid of Radial Basis Function Neural Network (RBFNN) technique is employed as an MPPT system for extracting optimal power from photovoltaic system. The excess energy obtained from the hybrid sources are stored in the battery and it is controlled by the recurrent neural network (RNN) with the bidirectional converter. The overall developed system is executed in MATLAB software and the most important outcomes are demonstrated in terms of high efficiency with 91.2%, high tracking efficiency of 98.54% and reduced THD of 2.45% respectively. The significance of results obtained in this research lies in the advancement of renewable energy integration technologies. By overcoming the challenges associated with intermittent energy sources, the developed system contributes to the improvement of grid stability and reliability

Worldwide LCOEs of decentralized off-grid renewable energy systems

Recent events mean that the security of energy supplies is becoming more uncertain. One way to achieve a more reliable energy supply can be decentralised renewable off-grid energy systems, for which more and more case studies are conducted in research. This review gives a global overview of the costs, in terms of levelised cost of electricity (LCOE), for these autonomous energy systems, which range from $0.03/kWh to about$1.00/kWh worldwide in 2021. The average LCOEs for 100% renewable energy systems have decreased by 9% annually between 2016 and 2021 from $0.54/kWh to$0.29/kWh, presumably due to cost reductions in renewable energy and electricity storage. Our overview can be employed to verify findings on off-grid systems, and to assess where these systems might be deployed and how costs are evolving