Supply Options Research Articles

The potential of electric agriculture and mobility for the least-cost rural electrification strategy in Sub-Saharan Africa

Electrification is a crucial driver of rural development in Sub-Saharan Africa (SSA), yet progress is often impeded by low demand density, particularly for grid extension. Despite the promising potential of stand-alone and mini-grid systems, rural areas frequently lag behind due to their low economic viability in electrification. Simultaneously, the mechanization of agriculture and the motorization of transport offer the opportunity to increase economic activity. This publication explores the role of electric vehicles (EVs) and electric tractors (ETs) in rural electrification scenarios.We present a methodology to quantify the theoretical impact of EVs and ETs on SSA’s electrification strategies, applied specifically to Nigeria and Chad. Our simulations in Nigeria reveal that not only supply options with higher capacity are needed, but that EVs have the potential to lower the cost of electricity (LCOE) by an average of 54 %, and ETs have the potential to reduce LCOE by 49 %, depending on local mobility and mechanization demand. Rural areas with significant cropland particularly benefit from using ETs to achieve cheaper electricity access. In Chad, where grid infrastructure is minimal, our assessment shows that EVs and ETs can significantly influence least-cost electrification strategies. By 2030, mini-grids will become the least-cost supply option for 60% of the newly connected population, compared to just 13% when only residential demand is considered.Our methodology advances the widely used ONSSET electrification planning model to estimate the maximum joint potential of electrified agriculture, electric mobility and adapted rural electrification strategies. Our approach involves geospatially estimating energy demands using macroscopic available population, land cover, and infrastructure data. The findings underscore the importance of jointly implementing EVs and ETs and electrification strategies for technology leapfrogging, highlighting the economic viability and potential of EVs and ETs in rural scenarios. The results provide policymakers with quantitative indicators on the impact of the implementation for Nigeria and Chad.

Effects of different nutrient supply options on system productivity, nitrogen use efficiency and soil enzyme activities in maize - wheat cropping system cropping system

The field experiments were conducted during during kharif and the following rabi seasons of 2011-12 and 2012-13 with five different treatments in maize (Zea mays L.) and wheat (Triticum aestivum (L.) emend Fiori & Paol.) cropping systems. Application of 50% RDF + 50% RDN recorded maximum WEY of maize (3.23 and 4.58 t/ha) and system productivity (8.20 and 9.03) over rest of the treatments, but remained statistically similar with other treatments except control during 2011-12 and 2012-13, respectively. The highest ANUE (5.07 and 15.36 kg grain yield increase/kg N applied) of maize crop was recorded at 50% RDF + 25% RDN + BF, followed by 50% RDF + 25% RDN during both the years. The highest ANUE (17.64 and 17.18 kg grain yield increase/kg N applied) of wheat crop were recorded from 37.5% RDF + 37.5% RDN + BF during both the years, respectively. Application of 50% RDF + 50% RDN to maize resulted in increased the value of MBC (18.0 and 18.4%), DH (22.9 and 18.6%), alkaline phosphatase (33.3 and 29.6%) and urease (37.1 and 37.8%) over control during 2011 and 2012, respectively. An increased value of MBC (38 and 34.6%), DH (29.2 and 29.8%), alkaline phosphatase (37.2 and 34.9%) and urease (30.1 and 25.6%) was recorded with the application of 37.5% RDF + 37.5% RDN + BF to wheat over control during both the years, respectively. Bangladesh J. Bot. 53(3): 429-438, 2024 (September)

Insights from a 19-year field study: optimizing long-term nutrient supply strategies for enhanced crop productivity and nutritional security in rice–wheat systems

What nutrient supply options can ensure maximum productivity and optimize the nutrient uptake of rice–wheat system (R-W system)? an experiment started in the year 1998 (19-year-old) to examine the impact of optimal nutrient supply (NS) strategies to maximize crop productivity and nutritional security in R-W system. To determine the best nutrient management strategies (BNMS), seven different NS methods were tested. These included (organic and mineral fertilizers), as well as combinations such as integrated plant nutrition system (IPNS), IPNS + B (berseem), and IPNS + C (cowpea), with the aim of enhancing the productivity and nutrient absorption of R-W system. Results showed that rice grain yield notably wide-ranging from 1.61 to 5.81 t ha−1 under different NS options and highest rice grain yield (mean of 19 years) was observed at IPNS + C (5.81 t ha−1), which was at par with IPNS (5.79 t ha−1), STCR (soil test crop response) (5.76 t ha−1) and IPNS + B (5.67 t ha−1) followed by 100% recommended dose fertilizer NPK (4.41 t ha−1), which equality with OF (organic farming) (4.04 t ha−1) and lowest was recorded in control plot (1.61 t ha−1). Wheat grain yield varied significantly from 1.43 to 5.86 t ha−1 under different NS options. The highest yield (mean of 19 years) was observed in treatments IPNS + B (5.86 t ha−1), IPNS (5.77 t ha−1), IPNS + C (5.48 t ha−1), and STCR (5.45 t ha−1), followed by OF at 4.49 t ha−1, NPK at 3.76 t ha−1, with the lowest in the control plot at 1.43 t ha−1. Additionally, total phosphorus and sulfur accumulation in rice (grain: 8.41 to 39.09 kg ha−1; straw: 6.02 to 23.54 kg ha−1) varied significantly across nutrient supply treatments. Overall, adoption of IPNS integration with legumes (IPNS + B and IPNS + C), can significantly improve productivity and nutrient accumulation in R-W systems. Incorporating legumes into farming practices is advised for sustained productivity and nutritional benefits.

Economic Case for Replacing High-Emitting Peaker Plants with Fuel Cells for Automotive Applications.

The identification of clean and cost-effective solutions to replace high-emitting peaker plants and support a just transition is a challenge faced by utilities across the US today. However, falling costs of hydrogen production as well as the widespread availability of fuel cells for automotive applications have made them an attractive option for a zero-emission peak power supply. This study evaluates the techno-economics, operation, and environmental justice impacts of siting a peaker plant based on fuel cells for automotive applications through the lens of the existing Intermountain Power Plant, in order to supply peak power to the Los Angeles basin. Compared to the fossil fuel-fired peakers in operation today, the fuel cell peaker would be lower-cost up to a 17% capacity factor with Inflation Reduction Act incentives while also reducing air pollution in environmental justice communities. With corresponding transmission upgrades, the Intermountain site could host up to a 5 GW fuel cell peaker in the future.

Design and Performance Evaluation of a Specialized Bubbler System for Accurate and Repeatable Solid Oxide Electrolysis Cell (SOEC) Testing

Accurate assessment of Solid Oxide Electrolysis Cell (SOEC) performance demands standardized testing conditions, particularly in stable steam delivery. Fluctuations in steam concentration and flow rate can significantly impact measured open-circuit voltage (OCV) and polarization behavior. Although direct steam injection is straightforward, it is often hindered by instability resulting from intermittent liquid water flux, pressure fluctuations, and fractional distillation effects. Bubbler humidification systems have the potential to offer consistent steam, but tailored designs for SOEC testing are currently absent.This study introduces a specialized bubbler system designed to deliver stable steam to SOEC test stands accommodating both oxygen-conducting (O-SOEC) and proton-conducting (H-SOEC) cells. The bubbler components include a refill water reservoir, a level control module, heating elements, pressure relief valves, check valves, tubing, and fittings integrated with the test stand. The system humidifies the sweep gas, transporting steam to the cell test fixture situated within a high-temperature furnace.The design process involved meticulous considerations of materials compatibility, hydrogen safety, and overtemperature protection. All wetted components employ stainless steel, glass, or PTFE materials in their construction construction. Redundant thermocouples ensure safe process temperatures with automated overtemperature shut off. The refill reservoir and bubbler headspace operate near ambient pressure, facilitated by an exhaust line vent sized for minimal backpressure.In various executed O-SOEC tests, the bubbler maintained OCV stability within ±5 mV over several hundred hours for each cell operating at 750°C, eliminating spikes caused by steam fluctuations observed with direct injection methods. This facilitates precise electrochemical analysis and determination of area-specific resistance losses. Polarization curves align with expected behavior based on the Nernst equation. The system has demonstrated safe and stable functionality for over thousands of hours across various operating conditions.The bubbler design presents researchers with notable advantages over existing steam supply options for SOEC test stands, addressing performance, safety, and flexibility concerns. Online instrumentation enables closed-loop control of steam conditions, enhancing stability. Standardization of test equipment is crucial for quality results, and this work contributes progress toward reproducible protocols in the international SOEC community. The modular bubbler approach, integrated with safety features, also signifies safer methodology choices for lab-scale experimental research.

Analysing micrologistics initiatives in rural areas – Approaches to typologise and assess complex logistics solutions in regional supply networks

While demand for regional products increases and societal expectations towards a regionalisation of production are on the rise in Germany, little attention is given to the logistical challenges of local producers. At the same time, rural areas are confronted with declining supply options for goods of daily needs. Logistical challenges in rural areas are primarily caused by a scarcity of actors, low or fluctuating quantities of goods and long transport distances. A lack of economies of scale makes supply and logistics very costly. Given the rising interest and new possibilities created by digitisation, numerous private and public initiatives are developing solutions for sustainable regional logistics to secure and improve supply in rural areas - so called micrologistics solution. However, a meta-analysis of such regional logistics solutions is missing that identifies similarities and differences and indicates which characteristics are essential for the development of long-term viable regional logistics solutions.This article therefore aims at providing a general overview and at systematising current micrologistics solutions in rural regions, introducing a typology which is based on a meta-analysis of approximately 80 micrologistics initiatives in Germany and beyond. Referring to two case studies – Smart Village St. Wendel and UCKER Warentakt - we then focus analysis on solutions aiming at providing goods of daily need to the population in rural areas. We share lessons learnt on their characteristics, challenges and factors of success. This is done using a specifically developed morphological box, a viability and impact-oriented assessment framework for micrologistics initiatives as well as results of interviews with initiators and operators of such initiatives. We conclude on the usefulness of the analytical approaches developed for this new research field as well as further research needs.

Geochemistry of fluoride mobilization in the hard-rock aquifers of central India: Implication for fluoride-safe drinking water supply

Globally, groundwater contamination by fluoride (F−) is a threat to the safe drinking water supply. Nevertheless, our understanding of the geochemical processes of F− mobilization to the groundwater by linking groundwater and aquifer material chemistry is limited. We therefore characterized that in the hard-rock aquifers of Central India, an area that has not been investigated thoroughly despite the known severity of the problem. Exploratory drilling of boreholes (n = 45) and lithostratigraphic modeling identified weathered basalt, vesicular basalt, fractured basalt, sandstone of Lameta, and fractured granite as major aquifers in the study area. The groundwater contamination by F− (concentration >1.5 mg/L) mainly occurred at depths >35 m bgl (at elevations <500 m amsl) of the fractured basalt and fractured granite aquifers, while samples collected from the shallow basalt, sandstone of Lameta, and shallow granite were mostly safe. The F− contamination of groundwater was primarily governed by the chemical evolution of groundwater along the flow path. Solute mass balance in groundwater, in conjunction with the mineralogical characterization of the aquifer materials, suggests that weathering of silicate and carbonate minerals was the dominant form of mineral dissolution in aquifers, which consumed dissolved CO2 along the flow path and resulted in an alkaline pH (>8) in groundwater of the deeper aquifers. The mobilization of F− in the groundwater could primarily be attributed to the ion exchange between OH− in water and structural F− in fluorapatite and F-bearing mica/amphibole. By assessing water quality and aquifer properties, this study suggests that primarily, the sandstone of Lameta and weathered and vesicular basalts can be targeted for F-safe drinking water supply in the study area. Targeting shallow aquifers can be an option for F-safe drinking water supply in other affected areas with similar geological and environmental settings.

STRATEGIC PLANNING USING THE TOTAL COST OF OWNERSHIP MODEL

In a highly competitive global scenario, companies seek new ways to optimize production and implement continuous improvement mechanisms to reduce costs. An essential tool in this context is the Total Cost of Ownership model, applied to the acquisition processes of inputs to determine the costs involved and compare the economic viability between domestic and international suppliers. Given the unstable economic scenario and high exchange rate fluctuations, the possibility of nationalizing production is evaluated. The case study method is adopted, characterized as applied and exploratory research, with the objective of generating knowledge for practical application and solving specific problems. This method combines a literature review with exploratory field analysis. The studied company faces a loss of profitability due to rising import costs, reduced demand, and the loss of purchasing power of the national currency against international suppliers. The increase in costs resulting from exchange rate fluctuations necessitates the search for new supply options, primarily in the domestic market, where exchange rate influence is lower. Thus, the nationalization of inputs becomes crucial in business decisions to minimize costs and maintain competitiveness. The results indicate that the nationalization of production using the Total Cost of Ownership model is viable. This model considers all costs involved in the acquisition of inputs, unlike the traditional acquisition model, which focuses exclusively on the unit price.

Game theory-based electricity pricing decisions incorporating prosumer energy preferences and renewable portfolio standard

The implementation of renewable energy-based power generation substantially enhances the greenness of the energy market. Concerns about pricing policies and widespread renewable energy (RE) industries have resulted in ongoing economic conflicts among stakeholders, including power companies (PCs) and different prosumer groups. This study proposes a game theory framework embedded in a pricing model to examine the influences of three-part tariff (3 PT) and renewable portfolio standard (RPS) on electricity pricing. Employing a Stackelberg game, the objective is to maximize stakeholders' profits through a sequential decision-making relationship between PCs (as the leader), and residential and industrial prosumers (as the followers). The findings reveal that the PC can maximize profit by coordinating the 3 PT and RPS, regardless of environmental awareness. Furthermore, given the prosumers’ preference for peer-to-peer (P2P) energy trading, the PC should employ a comprehensive approach encompassing 3 PT, P2P, and buy-back to maximize the total profit. On the energy trading platform, the relationship between residential and industrial prosumers is mutually beneficial, with the P2P scheme allowing residents to sell electricity while the industry approaches a lower electricity price from peer channels. Overall, understanding the energy preferences of prosumers should provide flexible and reliable power supply options for different groups of prosumers.

The one-humped camel: The animal of future, potential alternative red meat, technological suitability and future perspectives

The 2020 world population data sheet indicates that world population is projected to increase from 7.8 billion in 2020 to 9.9 billion by 2050 (Increase of more than 25%). Due to the expected growth in human population, the demand for meats that could improve health status and provide therapeutic benefits is also projected to rise. The dromedary also known as the Arabian camel, or one-humped camel (Camelus dromedarius), a pseudo ruminant adapted to arid climates, has physiological, biological and metabolic characteristics which give it a legendary reputation for surviving in the extreme conditions of desert environments considered restrictive for other ruminants. Camel meat is an ethnic food consumed across the arid regions of Middle East, North-East Africa, Australia and China. For these medicinal and nutritional benefits, camel meat can be a great option for sustainable meat worldwide supply. A considerable amount of literature has been published on technological aspects and quality properties of beef, lamb and pork but the information available on the technological aspects of the meat of the one humped camel is very limited. Camels are usually raised in less developed countries and their meat is as nutritionally good as any other traditional meat source. Its quality also depends on the breed, sex, age, breeding conditions and type of muscle consumed. A compilation of existing literature related to new technological advances in packaging, shelf-life and quality of camel meat has not been reviewed to the best of our knowledge. Therefore, this review attempts to explore the nutritional composition, health benefits of camel meat, as well as various technological and processing interventions to improve its quality and consumer acceptance. This review will be helpful for camel sector and highlight the potential for global marketability of camel meat and to generate value added products.

Electric vehicle charging by use of renewable energy technologies: A comprehensive and updated review

The majority of the vehicles in the world consuming fossil fuels that causes emissions of harmful greenhouse gases. In order to mitigate the emissions regarding the transport sector, Electric Vehicles (EVs) have attracted attentions. One of the main concerns in the development of EVs is supply of required power for the charging stations. Renewable energy systems would be clean and attractive options for supply of required power of charging stations. In recent years, several studies have investigated applications of renewable energy systems for charging stations of EV and analyzed different aspects of these technologies. This article reviews the research works on the design, optimization and performance investigation of charging stations coupled with renewable energy systems. Studies on EV charging systems powered by stand-alone or hybrid renewable energy systems are considered in the present article. According to the reviewed works, significant potential of renewable energy systems for supply of charging stations can be concluded. Different factors such as the applied technology and components, meteorological data of the installation site and operating condition influence the performance of these systems. Furthermore, it can be concluded that control design system can influence various aspects of EV charging technologies powered by renewable energy systems such as share of renewables in the grid-connected configurations and performance reliability. Challenges and opportunities associated with the development of these systems are provided in the current works and some recommendations are highlighted for the forthcoming studies and projects.

Hydro‐modeling the ecosystem impact of wastewater reuse under climate change: A case study in upper Red River basin, Oklahoma

AbstractWater reuse, as a viable option for water supply, must be implemented to minimize the adverse impacts on stream ecosystems that previously received this wastewater effluent. In the State of Oklahoma (OK), USA, local communities have implemented wastewater reuse, and many seek to expand the reuse programs. This study presents a hydro‐modeling analysis based on the Coupled Routing and Excess STorage with VECtor routing (CREST‐VEC) model focusing on the potential ecosystem impacts and societal benefits of wastewater reuse under climate change in the OK portion of the Red River basin. First, a CREST‐VEC model is established for the upper Red River basin and validated against observed streamflow for a 30‐year historical period (1990–2020). Based on the established model, we then assess the sensitivity of ecosystem impact to various climate change scenarios and hypothetical wastewater reuse scenarios. Results show that dominant effects of climate change cause the annual time below environmental flow to increase in the next 30 years, which constrains the room to implement wastewater reuse. However, at sub‐catchment scale, the analyses identify viable locations for allocating wastewater reuse while maintaining ecosystem health. The results also reveal that wastewater reuse brings about the most societal water benefits at minimal cost of ecosystem health under representative concentration pathway (RCP) 2.6 followed by RCP 4.5 and then RCP 8.5. Overall, the study demonstrates capabilities of the hydro‐modeling framework in developing water management plans facing the changing climate.

Assessing the Conservation Value of Artificial and Natural Reefs via Ichthyoplankton Spatio-Temporal Dynamics

The distribution of fish eggs and larvae (ichthyoplankton) reflects spawning and nursery areas as well as dispersal routes. This study’s goal is to demonstrate how the identification of ichthyoplankton species and stages and their spatial distribution among natural reefs (NRs) and artificial reefs (ARs) may serve as decision-making tools in conservation and fishery management. Natural reefs exhibited an eight-times higher abundance of eggs, as well as the highest abundance of larvae in the yolk-sac and preflexion phases. In contrast, ARs had the highest abundance of larvae in the flexion and postflexion phases. Natural reefs may serve as breeding grounds for Scaridae, Labridae, and Mugilidae; whereas, ARs may serve as breeding sites for Lutjanidae, Synodontidae, Carangidae, Fistularidae, and Haemulidae. Our study revealed differences between ARs and NRs, which demonstrate the potential of artificial reefs to expand the supply and settlement options of reef fishes and consequently can lead to increased fish production with potential benefits to adjacent fishing areas through connectivity. Thus, ARs as no-take sites can be effective tools for both fishery management and biodiversity conservation. The findings highlight the potential use of ichthyoplankton tools and the importance of considering both types of reefs in marine conservation and management efforts.

308 Awardee Talk: Prevention and mitigation of pathogens in feed and feed manufacturing systems

Abstract Prior to 2013, pathogen transmission through feed was focused primarily on bacteria and biosecurity was used to prevent adulterant entry into the ingredients and the feed mills. Following the porcine epidemic diarrhea virus (PEDV) outbreak in 2013, research focused on pathogen mitigation and control quickly became a subject of interest. Since PEDV, multiple endemic viruses and foreign animal diseases have been found to be transmissible in feed or feed ingredients. As African swine fever virus (ASFV) spread closer to the United States and endemic pathogens are a continued pressure on production systems, it is imperative that prevention measures are included in the feed supply chain and options for mitigation are fully elucidated for times of need. Previous research has demonstrated that preventative measures such as boot baths, lines of separation, showers, and changing clothes are effective measures when appropriately maintained. However, these protocols can seem costly and burdensome to employees, especially when the risk of disease transmission appears low. Employee training is difficult as disease transmission is difficult to visualize and exhibit the importance of each measure. Glo Germ, a florescent substance, is a cost-effective training tool which can demonstrate the efficacy of prevention protocols and can identify areas where biosecurity measures have not been properly utilized. Preventative measures are the first line of defense for feed manufacturing systems, but understanding and using mitigation techniques in the event of contamination can limit pathogen spread and protect the rest of the feed supply chain. Pelleting, as a method of thermal inactivation process, has recently been demonstrated to lessen the quantity of detectable viral RNA and decrease the risk of infection. The pelleting process, however, is a point-in-time mitigant and does not decrease the risk of product re-contamination as feed continues down the supply chain. The use of chemical mitigants, like formaldehyde, medium-chain fatty acids, and organic acids, can decrease the presence of bacterial and viral pathogens with longer-lasting mitigation properties. These mitigants can either be used in the feed itself, or as an addition to flushing batches which help disperse the chemical mitigants throughout the feed manufacturing equipment, thus reducing the risk of product re-contamination. In the event more drastic measures must be taken to eliminate pathogen presence from feed mills, gaseous fumigation and the use of portable heaters show promise as methods to decontaminate feed manufacturing equipment without the use of water or complete equipment breakdown. Overall, effective training and implementation of preventative measures are needed to provide pathogen-free feed to production systems, but continued research in mitigation and mill decontamination will further protect the feed supply chain in the event of pathogen contamination.

Evolving Power Factor Correction in Solar Water Pumping Systems through Zeta Converter-Based BLDC Motor Drives

The aim of this paper is to present the design and implementation of a new power conditioning system for a stand-alone solar-powered water pumping system. The system integrates a Brushless DC (BLDC) motor drive with a Power Factor Correction (PFC) Zeta converter to improve energy efficiency and reliability. In order to power BLDC motors for water pumping applications—which are essential for irrigation in isolated locations without access to the grid—the suggested solution attempts to overcome the difficulties related to the direct use of variable solar power. The PFC Zeta converter, which is the system's central component, is made to maximize power extraction from photovoltaic (PV) panels under fluctuating solar irradiation, guarantee high power factor, and reduce harmonic distortion in the electrical grid. A BLDC motor that powers a water pump is efficiently operated by this converter, which also optimizes the DC link voltage. A BLDC motor is especially well-suited for solar-powered applications due to its increased efficiency, dependability, and longer lifespan when compared to traditional induction motors. In order to continuously modify the PV panels' operating point to the maximum power point and maximize the amount of energy they capture, a Maximum Power Point Tracking (MPPT) algorithm is incorporated into the PFC Zeta converter's control strategy. The BLDC motor drive control strategy is carefully designed to guarantee seamless operation and flexibility in response to the fluctuating output from the solar panels, upholding the best possible pumping action in any solar situation. The system's capacity to sustain high efficiency and power factor under a variety of operating circumstances is demonstrated by the experimental findings. When the PFC Zeta converter is used, the solar-powered water pumping system performs much better overall. It shows a notable increase in energy conversion efficiency and lowers total harmonic distortion, which prolongs the pumping system's lifespan. By offering a solid method for raising the effectiveness and dependability of solar-powered water pumping devices, this study advances the sector and holds the possibility of a long-term water supply option for agricultural irrigation in isolated locations. In addition to utilizing renewable solar energy's environmental advantages, the suggested solution tackles the real-world difficulties associated with putting dependable and effective water pumping equipment into off-grid applications.

Numerical simulation on supply air of high sidewall grille with retrofitted energy recovery ventilator system for thermal comfort in the tropics

Energy recovery ventilator (ERV) is capable of being integrated into buildings to cut down energy usage for ventilation. However, retrofitting an ERV system into existing occupiable space with mixed ventilation presents drawback to the supply air considering the existing air distribution equipment on the ceiling is limiting the options for ventilation supply. The indoor airflow conditions from supply air of high sidewall grille with obstruction imposed by retrofitted ERV system were investigated for thermal comfort. Three cases of discharged angles of 0° horizontal blades, 45° upward blades and 45° downward blades at high sidewall grille in a studied classroom with tropical outdoor conditions were analyzed numerically. The investigation revealed that the obstruction imposed by ceiling-mounted supply duct in the ERV system can decrease comfort due to improper air mixing into the occupied zone. The results provided useful insight and practical implementation to ensure acceptable thermal comfort for the occupants in retrofitting an ERV in the context of mixed ventilation, which represents the most common design for air distribution in most existing buildings.

Системный анализ методов расчета систем электроснабжения карьеров

To optimize decisions on the choice of power supply options and obtain the greatest technical and economic efficiency in computer-aided design, it is necessary to improve the methodological base, develop economic and mathematical models of the most important and labor-intensive problems and algorithms for solving them using modern computer technology. In this work, a block diagram of an algorithm for computeraided design of power supply systems for quarries has been developed. The scheme provides the ability to calculate electrical loads taking into account the features of technology and mechanization of mining operations, select the number and power of transformer substations, calculate quarry distribution systems, compare options for power supply schemes taking into account changes in electrical loads and the dynamics of mining operations.

Flexibility options in a 100% renewable grid for Australia

Flexibility options for operating technologies available in a power system can facilitate the large-scale integration of variable renewable sources such as wind and solar whilst maintaining firm generation. In prior work, contributions of different flexibility options in future net-zero electricity networks vary widely across regions and scenario assumptions. Here we simulate a competitive-bidding process for an energy-only electricity system at 1-hour intervals to assess multiple flexibility options for supply and storage – including biomass, hydropower, concentrating solar power (CSP), electrical energy storage (EES), pumped hydro energy storage (PHES) and hydrogen (H2). We examine systemic effects of competing flexibility options and compare their grid-integrated cost-effectiveness in a future Australian 100% renewable grid. Our simulations indicate a variety of constellations with coexisting technologies, including flexibility options at various penetrations depending on storage cost and design points. We reveal the potentially significant role of long-term storage technologies (with months-deep discharge durations) in Australia's future 100% renewable grid, enabling significant reductions in the installed capacity of wind and solar PV, and thus overall system cost.

Design and Implementation of VSI for Solar Water Pump Control

The hardware design, implementation, and digital control method for three-phase AC induction motors based on Field-Oriented Control is discussed in this work Solar-powered water pumping systems have become an practical option for remote irrigation and water supply as renewable energy sources obtain importance. This research enhances such systems performance and dependability by employing a Voltage Source Inverter. In order to optimize the energy transfer to the water pump, the recommended approach uses the Voltage Source Inverter capabilities to transform the variable DC output of the solar panels into a controlled AC supply. The research looks at the choice of power components, control algorithms, and modulation strategies while designing the Voltage Source Inverter. The most suitable modulation strategy is determined after an in-depth review of several different approaches to ensure greater pump performance. This research clarifies on how solar energy conversion and pump control work together to provide sustainable water management in off-grid areas. The research paper "Design and implementation of VSI for Solar Water Pump Control" demonstrates how solar water pumping systems can be optimized using power electronics and control. The project addresses efficiency difficulties and operational differences to create efficient and reliable solar-powered water delivery systems, which support environmental sustainability and rural development. Based on the power of the PV panel, the P&amp;O MPPT method calculates the submersible pump speed. The sensorless speed control method eliminates the requirement for location or speed sensors. The Black Electro-Motives Force calculates speed by estimating the flux angle in the absence of mechanical speed sensors. This method reduces costs and simplifies the system simply by eliminating the requirement for expensive and complicated speed sensors. In order to determine steady-state and dynamic performance in varying insolation conditions, a prototype 5.5 KW inverter was constructed. In conclusion up, the research provided a thorough summary of the hardware and control aspects required for Field-Oriented Control in irrigation systems. The practical outcomes of this study have the potential to spur advancements in irrigation technology and the incorporation of renewable energy, resulting in substantial gains for agricultural productivity and environmental conservation.

Steady-state analysis of a hybrid power supply system using an induction generator with a shunt AC/DC converter

Hybrid power supply systems (HPSSs) are considered as a good option for electric power supply of remotely located from the grid consumers due to significant fuel savings compared to diesel sets. Quick development and improvement of HPSSs may be achieved using specialized methodologies and programs. In the paper a schematic diagram is proposed and operation principles of a 400 V / 50 Hz HPSS were developed. The system’s main component is the master generating unit of the hydropower plant using a 250 kW induction generator (IG). The voltage of the system is controlled by the controller of the AC/DC power converter. The electrical frequency of the system is controlled by the speed controller of the hydropower turbine. A wind turbine, an energy storage system and a regulated dump load are connected to the IG through the AC/DC converter. Goal. The paper aims to develop a methodology for steady state performance analysis of the hydraulic turbine driven isolated IG operating in parallel through an AC/DC power converter with additional sources and consumers of active power. Methodology. The methodology for evaluation of performance characteristics of the IG operating in the proposed system has been developed. The methodology is based on the equivalent circuit of the system, equations of active and reactive power balance in the system and the superposition method. Results. The equations of frequency, voltage and power regulators of the system are given. The performance characteristics of the IG operating in the system supplying resistive and RL load in «constant voltage – constant frequency» mode are obtained. Novelty. The developed methodology is innovative in taking into account the control algorithms of the system. The comparative analysis of the IG’s performance operating in the stand-alone generating unit and in the generating unit connected to the proposed system is performed. Practical value. The developed methodology can be used for development and performance improvement of hybrid AC power systems.