Search Results (20)

This paper proposes an analysis of different logics (heuristic and linear) of managing renewables scenarios including two different operating conditions and their relative degradation: fixed and variable point. The synergy between two storage technologies, such as Li-ion batteries and the hydrogen power-to-power solution (electrolyzer, H₂ tank, and fuel cells), is evaluated to ensure the balance of the power grid. This paper presents a numerical model of the smart grid developed in MATLAB/Simulink. A detailed performance evaluation of each component was performed to meet an electrical load (30 kW-peak) of a smart renewable energy community. From the optimization process, a fuel cell of 6 kW, an electrolyzer of 18 kW, a tank of 40 m³ at 200 bars, as well as a battery of 75 kWh were selected. The fuel cell operates during autumn and winter due to the lack of photovoltaic power generation, while its contribution is reduced during the summer period. In the heuristic logic, the minimum and maximum hydrogen levels are 18% and 60% of the tank volume (40 m³), respectively, while in the linear logic, they are 33% and 65%. The average value of the state of charge (SOC) of the battery is similar in both logics (0.51 vs. 0.53). Regarding hydrogen produced from the electrolyzer, the linear logic allows it to produce a quantity 7% higher than the heuristic one; therefore, the linear logic allows it to properly manage the electrochemical systems. The dynamic operation results in more significant degradation of hydrogen systems, making them less suitable; thus, to preserve the devices (up to 25% of lifetime more), a fixed-point operation is recommended. The cost comparison does not show relevant differences between the two scenarios, while a steep increase in the costs is shown when the fuel cell is operated in dynamic mode. Finally, the total emissions associated with renewable microgrids are 30 times lower than the traditional grid scenario, demonstrating the potential of renewable energy communities. Full article

Achieving net-zero emissions in arid and high-solar-yield regions demands innovative, cost-effective, and scalable energy technologies. This study conducts a comprehensive techno-economic analysis and assessment of a novel hybrid photovoltaic–thermal solar collector (U.S. Patent No. 11,431,289) that integrates a reverse flat plate collector and mini-concentrating solar thermal elements. The system was tested in Qatar and Germany and simulated via a System Advising Model tool with typical meteorological year data. The system demonstrated a combined efficiency exceeding 90%, delivering both electricity and thermal energy at temperatures up to 170 °C and pressures up to 10 bars. Compared to conventional photovoltaic–thermal systems capped below 80 °C, the system achieves a heat-to-power ratio of 6:1, offering an exceptional exergy performance and broader industrial applications. A comparative financial analysis of 120 MW utility-scale configurations shows that the PVT + ORC option yields a Levelized Cost of Energy of $44/MWh, significantly outperforming PV + CSP ($82.8/MWh) and PV + BESS ($132.3/MWh). In addition, the capital expenditure is reduced by over 50%, and the system requires 40–60% less land, offering a transformative solution for off-grid data centers, water desalination (producing up to 300,000 m³/day using MED), district cooling, and industrial process heat. The energy payback time is shortened to less than 4.5 years, with lifecycle CO₂ savings of up to 1.8 tons/MWh. Additionally, the integration with Organic Rankine Cycle (ORC) systems ensures 24/7 dispatchable power without reliance on batteries or molten salt. Positioned as a next-generation solar platform, the Hassabou system presents a climate-resilient, modular, and economical alternative to current hybrid solar technologies. This work advances the deployment readiness of integrated solar-thermal technologies aligned with national decarbonization strategies across MENA and Sub-Saharan Africa, addressing urgent needs for energy security, water access, and industrial decarbonization. Full article

Access to electricity is a prerequisite for development, included in both the Agenda for Sustainable Development and the African Union’s Agenda 2063. Still, universal access to electricity is elusive to large parts of the global population. In Somalia, approximately one-third of the population has access to electricity. The country is unique among non-island countries as it has no centralized grid network. This paper applies a geospatial electrification model to examine paths towards universal access to electricity in Somalia under different timelines and with regard to different levels of myopia in the modeling process. This extends the previous scientific literature on geospatial electrification modeling by studying the effect of myopia for the first time and simultaneously presenting the first geospatial electrification analysis focused on Somalia. Using the Open Source Spatial Electrification Tool (OnSSET), the least-cost electrification options towards 2030 and 2040, respectively, are compared. We find that under the shorter timeline, a deployment of mini-grids and stand-alone PV technologies alone provides the least-cost option under all but one scenario. However, under the longer timeline, the construction of a national transmission backbone would lower overall costs if there is high demand growth and/or low cost of centralized grid electricity generation. We also compare different levels of myopia in the modeling process. Here, OnSSET is first run directly until 2040, then in five-year time-steps and annual time-steps. We find that running the model directly until 2040 leads to the lowest costs overall. Running the model myopically leads to a sub-optimal, more costly technology mix, with a lock-in effect towards stand-alone systems. On the other hand, the myopic approach does provide additional insights into the development of the system over time. We find that longer-term planning favors the centralized grid network, whereas short-sighted myopic planning can lead to higher costs in the long term and a technology mix with a higher share of stand-alone PV. Full article

This paper presents a feasibility analysis of the technical, environmental, and economic sustainability of an existing mini-grid technology system in Nigeria. The study investigates the cost and other operational parameters of the Gbamu-Gbamu solar–battery–diesel hybrid mini-grid, specifically the 85 kWp solar PV installation in the Ijebu East Local Government area of Ogun state. Situated within the Owo forest in South-West Nigeria, the mini-grid aims to reduce the effects of global warming and promote sustainable technological development in rural communities by increasing energy access through renewable sources. To assess the system’s viability, this research utilized RETScreen Expert software to validate the techno-economic and environmental sustainability of the installed mini-grid solar–PV–battery–diesel system in the region. Climatic data for the study were obtained from the National Aeronautics and Space Administration (NASA). The results demonstrate that the system is economically feasible and environmentally viable, as indicated by the positive net present value (NPV) and an average monthly irradiance of 4.78 kW/h/m². Furthermore, the system achieved a 92.9% reduction in GHG emissions, provided a reasonable payback period of four years, and enabled a yearly electricity export of 203 MWh. These findings highlight the system’s potential to enhance energy access and mitigate climate change. Full article

Solar energy is considered a promising source of power generation in sub-Saharan Africa due to the high sunshine in these areas. Deploying decentralised solar-powered mini-grid systems to provide access to electricity in rural areas is fraught with difficulties in accurately predicting consumption, automatic monitoring, and operation sustainability to support the socio-economic conditions of rural communities. This study proposed SoAMIRural, which integrates solar PV mini-grid and advanced metering infrastructure for rural communities. SoAMIRural was implemented and tested for a case study community in Ghana. Solar PV Selection Equation Matrix (SPSEM) and Sample Size Equation (SSE) were used to determine the sustainable demand generation capacity of 24 kVA. Load estimations and need assessments were conducted to ascertain the rural community’s electric load and priority needs. SoAMIRural was evaluated with an error margin of 5%, resulting in 95% accuracy in energy consumption threshold management and monitoring to ensure energy conservation and sustainability of the mini-grid system. This study maps out a conceptual framework for a smart solar PV mini-grid system for rural communities and its advantages in realising SDG 7 in Ghana by 2030. Full article

PV-based mini-grids are identified as a feasible and, often, only economically viable option for the electrification of Kenyan remote and scattered rural areas, where connection to the national grid is challenging, and the related costs are high, if not prohibitive. This paper presents the analysis of typical Kenyan PV mini-grids by using some results of the work in the project “Reliable, Efficient and Sustainable Mini-Grids for Rural Infrastructure Development in Kenya (RESILIENT)”. After presenting average annual and seasonal daily load profiles of residential and small commercial mini-grid customers identified from the measured demands, the paper introduces the main mini-grid components and their models, including a simplified, but reasonably accurate, model of a mini-grid battery storage system based on the manufacturer’s charge–discharge curves. All mini-grid components are assembled in a scalable and easily reconfigurable simulation model of an actual Kenyan PV mini-grid, and they are implemented for the evaluation of PV mini-grid performance and the potential for expansion and connection of additional residential and small commercial customers. During the validation of the developed simulation model using available measurement data, an empirical approach for adjusting the PV system output power is specified for a more accurate match with the measurements. The presented results indicate the importance of the information on the actual control algorithms and control settings of the mini-grid energy management systems, on the thermal dependencies and characteristics of both PV generation system and battery storage system, and on the availability of on-site measurements of temperature and input solar irradiance. The developed PV mini-grid model can be used for further analyses, such as to study the techno-economic performance of different mini-grid configurations, to identify the optimal sizing of mini-grid components, and to specify efficient control and operation schemes based on the locally available resources. Full article

The electricity crisis is a common issue in Bangladesh; however, recently the electricity scenario has been getting worse due to various reasons including power generation and distribution all over the country. Meanwhile, the large number of people requires a huge amount of energy which is not possible to be met by the national grid due to the limited power generation from different plants. Among all renewable energy sources, the solar photovoltaics (PV) system is the best choice as a generation source, either off-grid or with a grid-tied connection, to reduce the pressure on the national grid. In Bangladesh, there are more than 175,000 schools, and it is possible to generate a huge amount of renewable (solar) power to supply all the schools by using rooftop PV systems. We propose a new approach that combines solar energy harvesting and savings to make the schools self-sufficient and energywise. We performed a Hybrid Optimization Model for Multiple Energy Resources (HOMER) pro simulation and find that it was possible to generate approximately 200 megawatts (MW) of power. We conducted a feasibility study on generating power from rooftop PV systems on school buildings and reduced the power consumption using retrofitted thin-film-coated glass by around 16–20% per day depending on the school size, which can help the national power grid system by either making all the schools off-grid or grid-connected to supply power to the national grid. In addition, we perform a HelioScope simulation to investigate the maximum upscaling of PV sizing for the rooftops of school buildings in Bangladesh to realize how to make each school a mini solar power station in the future. The HelioScope simulation performance showed that it was possible to generate approximately 96,993 kWh per year from one school building. Full article

Due to the significance of environmental aspects, the modeling of hybrid systems should be performed with the lowest cost and environmental pollution. Therefore, an effective and optimum sizing method can ensure acceptable performance. This paper implements a “technique for order performance by similarity to the ideal solution” (TOPSIS) method combined with the “analytic hierarchy process (AHP)” method to size a standalone system based on techno-economic parameters. For this reason, a survey was conducted to collect local load data on Monpura Island, located in Bhola, Bangladesh. Visible and design faults of the existing PV/diesel mini-grid have also been identified. Five alternative hybrid configurations have been considered as to evaluate the best optimum system. Two economic and one environmental criterion was used to size the system. Two experts specialized in energy systems evaluated the criteria and proposed the suitable system. Battery, wind and PV capital cost multipliers have been considered as to perform sensitivity analysis. According to techno-economic analysis and expert opinion, PV/biogas/wind has been found to be the most appropriate system among these configurations. The system has a cost of electricity (COE) of 0.691 (USD/kWh) and emits only 4.43 kg of CO₂ per year. The net present cost of the proposed system is 18% lower than the existing microgrid, and the model has lower emissions due to high renewable penetration. It was also found that integrating wind can significantly reduce battery capacity in the mini-grid. The proposed system consumes 34% less batteries than the existing system. Implementing this optimum system can result in greater benefit to the local people. Full article

In this paper, eCook batteries are considered to be synonymous with those electric cooking devices (eCook), such as electric pressure cookers, induction cookers, hotplates or rice cookers, that can be connected to and supplied from a battery, which may or may not be fully integrated within the device. Connecting many eCook batteries can have an impact on the operation of a hybrid photovoltaic (PV)/diesel mini-grid network unless managed appropriately. The network could experience voltage fluctuations, system power losses and increased peak demand if all or most of the connected eCook batteries charge during a relatively “narrow” window of sunlight hours. Hence, this paper focuses on maximizing the number of eCook devices accommodated by the mini-grid, in keeping with increased consumer uptake, by regulating the charging rate (C-rate) of the eCook batteries themselves. The impact of varying the C-rate on the network constraints is assessed through a range of contextualized case studies. This entailed modeling an innovative smart eCook battery management system (EBMS) that actively monitors the state of the grid and decides on the eCook’s battery C-rate set-point required to address the network constraints. The results demonstrate that the EBMS can alleviate the impact of conventional eCook battery charging on the mini-grid network, as well as increase the quality of the charging service. Full article

Hybrid systems have gained significant attention among researchers and scientists worldwide due to their ability to integrate solar cells and supercapacitors. Subsequently, this has led to rising demands for green energy, miniaturization and mini-electronic wearable devices. These hybrid devices will lead to sustainable energy becoming viable and fossil-fuel-based sources of energy gradually being replaced. A solar photovoltaic (SPV) system is an electronic device that mainly functions to convert photon energy to electrical energy using a solar power source. It has been widely used in developed countries given that they have advanced photovoltaic (PV) technology that reduces dependence on fossil fuels for energy generation. Furthermore, a supercapacitor is an alternative solution for replacing heavy batteries and it is a system with a prominent high power density and a long life cycle. Its unique properties of high capacitance with low voltage limits lead to this highly in-demand material being incorporated into goods and services that are produced by the electrical and electronics industries. It is another option for grid-based power or large batteries. Since supercapacitors have the ability to store huge amounts of energy, they allow for a novel system that integrates supercapacitors with solar cells in which energy generation and energy storage are combined into one system. This paper explores the common materials that are used for solar cells and supercapacitors, the working mechanisms, the effectiveness of the integrated device and the technical challenges that are encountered when refining this device. Hence, this review serves as a guide for choosing the right materials and methods in order to produce an integrated PV solar cell–energy storage device for various applications. Full article

Solar home systems (SHS) represent one of the most promising technologies for a rapid and independent electrification in those areas of Sub-Saharan Africa (SSA) without access to electricity. This study addressed the environmental impact of SHS in SSA through updated life cycle inventories and five impact categories: greenhouse gases (GHG) emissions, fossil fuels, metal and water depletion and human toxicity. Sixteen scenarios were considered, including manufacturing, transportation, recycling and user-related variables, such as the installation site, adequacy of SHS user operation and battery lifespan. The results showed that lead-acid batteries were the largest contributor to environmental impact among the SHS components, accounting for up to 36–76% of the environmental impact indicators. Apart from the components, user training for SHS operation, with the goal of maximizing usable energy and battery lifetime, proved to be critical to achieve improvements in the energy payback time and GHG emissions, which (under scenarios of high solar resources) can reach the range of 5.3–7.1 years and 0.14–0.18 kgCO${}_2$ eq/kWh, respectively. In addition, SHS GHG emission factors were benchmarked with those of other electrification approaches, such as national grids, 100% PV and hybrid PV-diesel off-grid mini grids and off-grid diesel generators. SHS achieved GHG emission factor values equivalent to PV-based mini grids in most scenarios and was strikingly lower compared to SSA national grids and diesel generators. Full article

Achieving universal electricity access is a challenging goal for the governments of developing countries such as Ethiopia. Extending the national grid to the remotely located, scattered, and island populations demands a huge investment. This paper aims to show the techno-economic feasibility of minigrid renewable energy system to electrify Kibran Gabriel island in Ethiopia, through the execution of simulation, optimization and sensitivity analysis using Hybrid Optimization Models for Energy Resources (HOMER Pro) software. The minigrid systems were compared with both diesel generation (DG) and grid extension systems. The hybrid photovoltaic (PV)/DG/battery system is more economically feasible compared with other minigrid systems, and the best cost-effective option is the one including load flow (LF) strategy with 25 kW of PV, 10 kW of DG, 40 kWh of battery, and 5 kW of bi-directional convertor. The optimal PV/DG/Battery system, having levelized cost of energy (COE) of USD 0.175/kWh, net present cost (NPC) of USD 119,139 and renewable fraction (RF) of 86.4%, reduces the pollutant emissions by 33,102 kg/yr compared with the stand-alone DG system. The optimal minigrid sensitivity to the variations in global horizontal irradiance (GHI), diesel price and load consumption were considered in the sensitivity analysis, and the result shows that the system will operate reasonably well. Full article

The United Nations Sustainable Goal 7, access to affordable and clean energy, is unlikely to be achieved, with an estimated 600 million people still without access to electricity by 2030. One potential route to support this goal is through the use of mini-grids to provide electricity in densely populated rural areas for which grid connection is not possible. This paper presents the results of a life cycle assessment of a mini-grid, designed for construction in Malawi. It analyses the cradle to end of use for this mini-grid configuration, for a grid sized for lighting, refrigeration and phone charging, and for a grid sized for electric cooking (e-cooking). The results suggest that for lighting configuration, the main contributors to environmental impact are the poles, the overhead cabling, and the PV panels. The use of a chromium-based preservative is the main issue for the poles, and a switch to concrete poles can deliver significant benefits. When the grid is sized for e-cooking, the PV panels become the greatest contributor. Adding a diesel generator to the mini-grid configuration can reduce number of panels required and hence the environmental impact, but only if the generator is used for no more than 2 h per day. Full article

Strategies for meeting Sustainable Development Goal 7 of providing access to electricity for all recognize the important role that off-grid solutions will need to play. Mini-grids will from part of this response, yet little data exists on household demand from these customers. Predicting demand accurately is a crucial part of planning financially viable mini-grid systems, so it is important to understand demand as fully as possible. This paper draws on metered data from two solar PV diesel hybrid mini-grid sites in Tanzania. It presents an analysis of load profiles from the different sites and categorizes households by demand characteristics. The paper then combines load profile data with household demographic and electrical asset ownership data to explore factors behind distinct load profile patterns of use. It concludes that load profiles are determined by a complex mix of appliance ownership, occupancy, and socio-economic status. Full article

This paper lays out a methodology that could be used by mini-grid developers to assess the design readiness and future design requirement to accommodate electric cooking (eCook). While mini-grids in developing countries continue to grow in popularity, typically their designs are not yet sufficiently developed to accommodate large power appliances. Moving towards clean cooking using electricity will cause technical risks for mini-grids in terms of voltage drop, voltage unbalances and capacity shortage. In this paper, these parameters are studied on a mini-grid network modeled in OpenDSS/MATLAB as a simulation platform, where the selected mini-grid topology is hub and spoke. Two network studies are considered, the first investigates the limitations of the mini-grid in terms of the generation capacity available to supply the demand for different levels of eCook penetration, while the second focuses on the network constraints for different eCook penetrations. In general, the results show that voltage drop and voltage imbalance issues can be reasonably and affordably addressed by using cables of a larger cross-sectional area. The main issue prohibiting higher penetrations of eCook centre on generation capacity requirements, which led to a techno-economic analysis being conducted to assess future mini-grid sizes as well as targeting economic and environmental objectives and meeting the overall demand on a generically representative mini-grid in a rural region in East Africa. The discussion section in this paper highlights the main barriers to the accommodation of eCook on rural mini-grids and presents suggestions for future work that addresses new design specifications for the next generation of eCook mini-grids. Full article