A Case Study on Off-grid Microgrid for Universal Electricity Access in the Eastern Cape of South Africa

Microgrid is progressively an option for electricity access in unelectrified areas in developing nations. This study investigates the costs of microgrid solutions in comparison to grid extension to provide universal electricity access in Ntabankulu Local Municipality, Eastern Cape, South Africa. The Hybrid Optimization Model for Electric Renewable (HOMER) software was used to carry out simulation, optimization and sensitivity analyses. The results showed that a Wind/Diesel Generator/Battery-powered microgrid has the lowest cost with a breakeven grid extension distance of -45.38 km. The proposed microgrid could supply electricity at $0.320/kWh, with 0.0057 kg/kWh CO2 emissions and 90.5% renewable fraction, which are lower than grid extension. Therefore, a Renewable Energy Source (RES) hybrid microgrid solution can be a viable option for electrifying far-from-the-grid unelectrified areas of the Eastern Cape

Renewable energy solution for electricity access in rural South Africa

Abstract: South Africa has grown from 34% electrification in 1991 to about 84.7% electrification presently, but with least access to electricity in rural areas. The lower rate of electrification in rural areas than urban areas has made dwellers in rural unelectrified areas to be challenged economically, socially, educationally, health-wise, etc. The aging, unclean, nonrenewable and constrained traditional grid has necessitated to think out of the box for universal electricity access in the nation through renewable energy sources (RES) such as solar, wind, biomass, and hydro for rural electrification. Therefore, a RESpowered microgrid is designed for rural Jozini municipality with 26.3% electricity access. This proposed Jozini microgrid was found to have a Levelised Cost of Electricity (LCOE) of R0.384/kWh, which is about one-third of grid LCOE in South Africa. Also, the proposed Jozini microgrid has 0 kg/kWh CO2 emission compared to 0.99 kg/kWh CO2 emission from the traditional national grid

A community electrification project: combination of microgrids and household systems fed by wind, PV or micro-hydro energies according to micro-scale resource evaluation and social constraints

When electrifying isolated rural communities, usually standardized solutions have been implemented using the same technology at all the points. However these solutions are not always appropriate to the community and its population. This article aims to describe the technical design of the electrification system of the community of Alto Peru (in the region of Cajamarca, Peru), where the adequate technology was used at each area according to micro-scale resource evaluation and the socioeconomic requirements of the population. Specifically four technologies were implemented: wind microgrids in highlands, a micro-hydro power plant in the presence of a waterfall, a PV microgrid in a group of points sheltered from the wind and individual PV systems in scattered points with low wind potential. This project brought electricity to 58 households, a health center, a school, a church, two restaurants and two shops.Peer ReviewedPostprint (author’s final draft

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

Techno-economic comparison of standalone microgrids for rural electrification in South Africa

Rural electrification is a global problem that primarily affects developing countries. The people worst affected are people living in sub- Saharan Africa. There are number of reasons why rural electrification is generally low. People in rural areas generally live in small communities, located far away or from the grid or in geographically tough terrain. As a result, it is not financially viable to extend the grid to these areas and therefore they remain unelectrified. Another dictating factor, is the fact that people in these areas are generally poor, and therefore this discourages any investment from the private sector. This dissertation focuses on rural electrification in South Africa specifically. Most people in South Africa affected by not being electrified live in rural areas on the border between the Eastern Cape and Kwa-Zulu Natal. As it is too expensive to extend the grid to these areas, off-grid options, such as microgrids were investigated. A large amount of research has been carried out on hybrid microgrids as a solution to rural electrification. However, a limited amount of research has been carried out on single source microgrids. Furthermore, South Africa is fortunate to have an abundance of solar, wind and microhydro resources, however, it is unclear which resource would be cheapest based on the location of the rural area. As a result, the aim of thesis was to analyse the impact of the strength of the resource when implementing a microgrid and comparing the three different renewable resources systems against one another. In order to carry out this analysis, three unelectrified villages were selected with each village located in an area of a strong resource, whether it be wind, solar or microhydro. i.e. one village was selected in an area with a strong solar resource, the second in an area with strong wind resource and the third in an area with strong microhydro resource. Once selected, a load for each village was modelled and the resource data for each village was obtained using open source sites. Solar-battery, wind battery and microhydro-battery systems were modelled for each village using HOMER. From the results it was clear that when comparing the same resource in each of the villages, then the strength of the resource did affect the levelised cost of energy i.e. the stronger the resource, the less the lower the cost of energy which was as expected. However, when comparing the solar, wind and microhydro system in each village against each other, it was apparent that the strength of the resource did not dictate the type of technology to be used in that area. It was found that wind systems were not suited to small scale generation, whilst microhydro was the cheapest technology in each village, however, its implementation may be deterred by non-technical issues such as the social and environmental impacts of constructing a dam. The cost of the solar system was comparable to microhydro only when the irradiation was above a certain level. As solar systems are easier and quicker to implement it is possibly the best system in general for rural areas in South Africa. Implementation of off-grid systems for rural electrification in South Africa is a viable option however, as the private sector is not incentivised to implement these systems, then government back in the form of grants and subsidies are required to implement these systems. However, as renewable technologies improve and get cheaper with time, this option to electrify rural areas is always becoming cheaper

Integrated design of photovoltaic power generation plant with pumped hydro storage system and agricultural facilities in Uhuelem-Amoncha African community

Seasonal and location dependence of renewable energy resources have limited their applications in power generation. Energy storage systems are promising solutions to the intermittence of renewable energy resources. Rural electricity grids are faced with economic sustainability challenges due to low power demand and poverty. As countries hopefully pass through various stages of development, their needs change. The electricity needs of developing countries surely differ from those of developed economies. Most of the global population without access to electricity, and all the consequences of it, is found in developing countries. Energy access is undoubtedly a significant catalyst for development. Developed countries mainly require technologies to ensure energy security, resilience, and occasionally emission control. Therefore, microgrids are emerging technologies capable of supporting the diverse needs of various stages of development. For example, a rural grid design around economic drivers like agriculture and micro industries can mitigate poverty and improve economic sustainability of rural grids. This study presents an Integrated Design of Photovoltaic Power Generation Plant with Pumped Hydro Storage System and Agricultural Facilities in Uhuelem-Amoncha African Community. The design explored the natural availability of water body in an elevated settlement area that offers a natural storage height for hydro energy storage. HOMER (Hybrid Optimization of Multiple Energy Resources) software was deployed to optimize the design. The designed photovoltaic power generation plant has a nominal capacity of 221 kW. The simulated results show the power supply probability of the plant as 99.9%. The cost of energy (COE) offered by the design is 0.456 [US$/kWh] which is 82% lower than the current cost of energy in the project community based on generation through petrol generators. The System has 100% renewable energy penetration. The plant is designed to power 50 households with a daily domestic energy consumption of 4.46 [kWh] each. The plant capacity also covers the irrigation water requirement of 50 acres of corn farms. A total of 100 units of designed intelligent pest control system will also be powered by the plant. A community refrigeration scheme of 27 [m3] equivalent volume is part of the plant design load. The benefits from the irrigation, water supply, pest control and refrigeration scheme will enhance the community’s socio-economic development and sustain the investment. Quantifying the integral socio-economic and environmental benefits is a subject of a future research

Design and implementation of rural microgrids : Laguna Grande case study

In 2015 the United Nations established the 17 Sustainable Development Goals: a set of interrelated objectives and a guide to reach a more sustainable and higher quality future for all humanity. The goals were set with a timeline for 2030, the seventh goal refers specifically to the universal access to “affordable and clean energy”. Taking account the considerable fraction of world population that do not have access to electricity, especially in rural areas, this goal still requires a great effort and investment. Rural hybrid microgrids, that integrate and manage solar and wind energy resources to provide electric service to remote locations, are a promising solution to reach this “last mile” scenario. However, as is reported in the literature, there is still scarce information about the performance of these systems based on measured data obtained in real working field conditions. This work aims to contribute to this aspect mainly by analyzing the data obtained in the 9 kW Laguna Grande community hybrid microgrid, which is cooperative since 2016 in the coast of Perú, and has been equipped with sensors and data acquisition systems that measure and register solar radiation, wind speed, temperatures, and all the relevant electric parameters. As a preliminary study, the rural electrification gap and costs are assessed, as well as the availability of solar and wind resources in the area of interest. A literature and state of the art review is undertaken followed by the definition of the microgrid concept and the different ways in which a rural microgrid can be configured. The particular way in which the Laguna Grande microgrid is configured and instrumented is described. Measured meteorological conditions as solar radiation, wind speed and temperature are analyzed and related to the power generated by the photovoltaic arrays and wind turbine. This in turn leads to a balance with respect to the power delivered to the community and consequently to the voltage levels of the battery bank. Battery dynamics concepts are used to determine the depth of discharge (DOD) of the batteries in a real time regime. The statistics of the DOD values allows for the duration of the battery to be estimated which is a key factor to the microgrid economics and reliability. A parametric study is done to assess the effect of varying battery size on the technical and economic performance of the microgrid; similarly, with generating capacity in both photovoltaic arrays and wind turbines. Complementarily, a commercial software is used to optimize the microgrid, introducing state of the art components as lithium-ion batteries, power electronics and photovoltaic modules for a future upgrade. Finally, this study would not be complete without emphasizing the importance and adequate consideration of the human factor for the success and long-term sustainability of rural electrification projects.En el año 2015 las Naciones Unidas estableció los 17 Objetivos de Desarrollo Sostenible: un conjunto de objetivos interrelacionados y una guía para alcanzar un futuro más sostenible y de mayor calidad para toda la humanidad. Las metas se establecieron con una línea de tiempo para el 2030, la séptima meta se refiere específicamente al acceso universal a “energía limpia y asequible”. Teniendo en cuenta la fracción considerable de la población mundial que no tiene acceso a la electricidad, especialmente en las zonas rurales, este objetivo aún requiere un gran esfuerzo e inversión. Las microrredes híbridas rurales, que integran y gestionan los recursos de energía solar y eólica para proporcionar servicio eléctrico a lugares remotos, son una solución prometedora para llegar a este escenario de “última milla”. Sin embargo, como se reporta en la literatura, aún existe poca información sobre el desempeño de estos sistemas basada en datos medidos y obtenidos en condiciones operativas, reales de campo. Este trabajo busca contribuir en este aspecto principalmente mediante el análisis de los datos obtenidos en la microrred híbrida comunitaria de 9 kW en Laguna Grande, que está operativa desde 2016 en la costa de Perú. Esta microrred ha sido equipada con sensores y sistemas de adquisición de datos que miden y registran la energía solar, radiación, velocidad del viento, temperaturas y todos los parámetros eléctricos relevantes. Como estudio preliminar se evalúa la brecha y costos de electrificación rural, así como la disponibilidad de recurso solar y eólico en la zona de interés. Se realiza una revisión bibliográfica y del estado del arte, seguida de la definición del concepto de microrred y las diferentes formas en que se puede configurar una microrred rural. Se describe la forma particular en que se configura e instrumenta la microrred de Laguna Grande. Las condiciones meteorológicas medidas como la radiación solar, la velocidad del viento y la temperatura se analizan y relacionan con la energía generada por los arreglos fotovoltaicos y la turbina eólica. Esto a su vez conduce a realizar un balance con respecto a la potencia entregada a la comunidad y consecuentemente a los niveles de voltaje del banco de baterías. Los conceptos de dinámica de batería se utilizan para determinar la profundidad de descarga (DOD) de las baterías en un régimen a tiempo real. Las estadísticas de los valores DOD permiten estimar la duración de la batería, lo cual es un factor clave para la economía y confiabilidad de la microrred. Se realiza un estudio paramétrico para evaluar el efecto de variar el tamaño de la batería en el desempeño técnico y económico de la microrred; de igual forma, con la capacidad de generación tanto en arreglos fotovoltaicos como turbinas eólicas. Complementariamente, se utiliza un software comercial para optimizar la microrred, introduciendo componentes de última generación como baterías de iones de litio, electrónica de potencia y módulos fotovoltaicos para una futura actualización. Finalmente, este estudio no estaría completo sin enfatizar la importancia y la adecuada consideración del factor humano para el éxito y la sostenibilidad a largo plazo de los proyectos de electrificación rural.Postprint (published version

Techno-Economic Feasibility Study of Autonomous Hybrid AC/DC Microgrid System

Distributed generation technology based on diesel generators often has been considered as a viable solution to providing power to remote areas, but the sky‐rocketing of diesel fuel price and the increasing cost of delivery to such remote sites have called for providing a sustainable solution that is environmentally friendly, economical, affordable, and easily accessible. To this end, the use of locally available energy resources is accepted as a sustainable solution in providing electricity for rural and remote settlements. The system cost of wind and solar energy systems is continuously decreasing because of the increase in the acceptance and deployment of the energy systems based on these renewable energy resources. A standalone hybrid AC/DC electric power system is designed, modeled, simulated, and optimized in HOMER Pro. HOMER is a Hybrid Optimization Model of Electric Renewable that enables the comparison of electric and thermal power production technologies across an extensive variety of applications. Both cycle‐charging and load‐following dispatched strategies are investigated. Plausible selected system components ratings are chosen for the simulation to ensure that there is enough search space for HOMER Pro to obtain an optimal system configuration. Net present cost (NPC) is used as an economic metric to assess the optimal configuration that is technically feasible

Dimensioning Microgrids for Productive Use of Energy in the Global South—Considering Demand Side Flexibility to Reduce the Cost of Energy

Microgrids using renewable energy sources play an important role in providing universal electricity access in rural areas in the Global South. Current methods of system dimensioning rely on stochastic load profile modeling, which has limitations in microgrids with industrial consumers due to high demand side uncertainties. In this paper, we propose an alternative approach considering demand side management during system design which we implemented using a genetic scheduling algorithm. The developed method is applied to a test case system on Idjwi Island, Democratic Republic of the Congo (DRC), which is to be powered by a micro hydropower plant (MHP) in combination with a photovoltaic (PV) system and a battery energy storage system (BESS). The results show that the increased flexibility of industrial consumers can significantly reduce the cost of electricity. Most importantly, the presented method quantifies the trade-off between electricity cost and consumer flexibility. This gives local stakeholders the ability to make an informed compromise and design an off-grid system that covers their electricity needs in the most cost-efficient way