Off-grid Solar System Research Articles

Optimal Design of an Off-Grid Solar Energy System Integrated with a Diesel Generator for Urban Areas in Pakistan

The growing energy demand in Pakistan, coupled with the challenges posed by reliance on imported fossil fuels, necessitates the exploration of alternative energy solutions. This study presents the design and techno-economic analysis of an off-grid hybrid energy system tailored for a residential neighborhood in Karachi, Pakistan. The system integrates individual solar energy solutions for seven housles, supplemented by a shared diesel generator to ensure a reliable power supply, particularly during load-shedding and grid outages. The study utilizes HOMER Pro software to model and optimize various configurations, taking into account local solar insolation levels and seasonal variability in energy demands. The optimized system includes photovoltaic (PV) panels, battery storage, and a shared diesel generator with individual connections and meters, with each house receiving a customized solution based on its specific energy requirements, ranging from 15 kWh/day to 45 kWh/day. The shared diesel generator is designed to reduce the need for large battery banks, thereby minimizing both capital and operational costs. The results demonstrate a cost-effective solution with a Levelized Cost of Energy (LCOE) of $0.2959/kWh and a Net Present Cost (NPC) of $15,562.55 over a 25-year period. This research highlights the potential for implementing such systems in urban areas of Pakistan, offering a sustainable, reliable, and economically viable alternative to conventional energy sources.

Load profiles of residential off-grid solar systems on the Navajo Nation

Standalone off-grid electrical systems, no matter where they are deployed or for what user class, are designed based upon the load they are expected to serve. State-of-the-art computerized off-grid system design tools require the user to specify the expected load profile, that is, how the power consumption changes throughout the day. Often, this is at an hourly resolution, and some characterization of the distribution of power around the average values may be required. Specifying realistic and reasonable load profiles is a barrier to the appropriate design of standalone systems. This research extends previous studies on daily energy consumption of residential solar-powered off-grid systems on the Navajo Nation to provide hourly load profiles, statistical characteristics, and probabilistic models. The data analyzed come from 90 homes over a two-year period. K-means clustering is used to identify prototypical normalized load profiles when the data are grouped by year, season, weekday, and weekend. Eight parametric probability density functions are fit to the grouped data at an hourly resolution. Their fit to the data is evaluated using the Cramér-von Mises (CvM) statistic. The results show that the load profiles tend to be night-peaking and that Log Normal and Gumbel distributions can reasonably model variation in the data. The load profiles and probabilistic models can be used in off-grid design software and to synthesize load profiles for design and future research.

Hybrid solar and hydrogen energy system 0-D model for off-grid sustainable power system: A case in Italy

Off-grid solar systems are one of the most promising solutions for achieving complete grid independence. However, the storage of large amounts of energy produced in the summer through solar panels becomes crucial to reach this goal and hydrogen, as a zero-CO2 energy carrier, could play a pivotal role. This paper presents a case study on the integration and simulation of solar energy and hydrogen technologies in an off-grid energy plant for a teaching buildings complex in Italy. A 0-D virtual energy plant model has been developed aimed at estimating the net energy production and hydrogen consumption/production rates using different inputs of irradiance (monthly average, daily) and energy demand (constant and variable daily consumption levels) in the buildings. The outcome of the analysis identifies the most convenient configuration of the plant in terms of sizing and device interactions for achieving complete grid independence, and the impact of different inputs on the plant performance.

Performance evaluation of off-grid solar systems for critical medical instruments in remote regions

In areas with limited access to electricity or during power outages, ensuring continuous and reliable use of grid-powered electrical instruments is challenging, especially in remote emergency centers. A stable source of electricity is crucial to prevent disruptions in power supply, as they can lead to severe medical complications, jeopardize patient well-being, and even result in fatal incidents. To address this issue, integrating renewable electricity sources such as off-grid solar systems into existing power supply infrastructure can be a viable solution. Recent studies suggest that off-grid solar systems can be reliable and sustainable options for powering medical facilities, particularly in areas lacking uninterrupted grid connectivity. Therefore, this research aims to evaluate the feasibility, benefits, and challenges of integrating off-grid power to support critical medical instruments. Based on an extensive literature review, interviews with experts, and surveys among relevant users, this study finds that the system has the capability to maintain a consistent, dependable power supply, even during adverse weather conditions. Cost and feasibility are highlighted as paramount considerations, based on surveys and focus group results. The study concludes that off-grid solar systems offer an economical, low-maintenance, and environmentally sustainable alternative for remote medical facilities. Finally, this study proposes recommendations to optimize critical device performance during power outages and improve overall system functionality and efficiency.

Influence of a Dual Axis IoT- Based Off-Grid Solar Tracking System and Wheatstone Bridge on Efficient Energy Harvesting and Management

Influence of a Dual Axis IoT- Based Off-Grid Solar Tracking System and Wheatstone Bridge on Efficient Energy Harvesting and Management

Maximizing Solar Panel Performance: A Comparative Study of Aluminum and Copper Panel Integration in Off-Grid Systems

Abstract: This study explores the implementation of off-grid solar energy systems with strategically mounted aluminum panels behind solar panels, aiming to devise an efficient, economical, and environmentally friendly design. The research builds upon existing literature in the field, focusing on optimizing solar panel performance. Through a comprehensive analysis involving voltage, current, temperature, and solar radiation, the study achieved a notable 1-2% increase in solar panel efficiency. Notably, this enhancement is realized without the need for additional space, making the proposed design a practical and space-efficient solution. The findings underscore the potential of this approach as a permanent, cost-effective, and environmentally conscious solution for PV solar panel installations. With the escalating costs of conventional electrical energy, the study advocates for the adoption of this method, aligning with the global push towards sustainable and eco-friendly energy alternatives. The insights gleaned from this research contribute valuable knowledge to the ongoing discourse on advancing renewable energy technologies, emphasizing the significance of efficient and sustainable solutions in the transition towards a cleaner energy future.

Evaluating the impact of industrial loads on the performance of solar PV/diesel hybrid renewable energy systems for rural electrification in Ghana

Access to reliable electricity remains a significant challenge in many rural communities worldwide. Off-grid solar PV hybrid renewable energy systems (HRES) have emerged as a viable option for rural electrification. However, rural communities' lack of productive load often limits their effectiveness. This study aimed to assess the impact of agro-processing productive loads on the performance of off-grid solar PV HRES for rural electrification. Hybrid Optimization Multiple Energy Resource (HOMER) software was used to perform a techno-economic analysis of a solar PV/diesel HRES. The study findings showed improvement in the rural community's load factor and solar load correlation with the integration of the productive load. Subsequently, increasing the renewable energy fraction in solar PV/diesel HRES reduces the levelized cost of energy (LCOE), making electricity generation more cost-effective for rural electrification in Ghana. Comparatively, the improved LCOE was found to be substantially higher than the End User Tariff of all residential consumers on the national grid, even under high PV penetration and full capital cost subsidy cases. The study provides valuable insights into the role of agro-based productive loads in enhancing the performance of rural off-grid solar HRES.

Analysis of Battery Testing Protocols in the Transition from the Lab to the Field: A Test Case Using Advanced Zn-MnO2 Batteries in Off-Grid Solar Microgrids

Understanding cycling performance of batteries under varying conditions is crucial for continued development of emerging chemistries. Currently much of this work is focused on cycling single cells in well-controlled lab experiments. There are few module cycling studies in the open literature. Studies of full-sized fielded systems are even rarer. As a result of this data gap, there is limited understanding of how single cell cycling can be used to predict performance of fielded systems prior to their deployment.Sandia National Laboratories (SNL) recently deployed an advanced Zn-MnO2 secondary battery energy storage system in an off-grid solar plus storage system. Using this deployment as a test case, we will detail how performance and degradation for batteries can vary between the lab and the field. We will also discuss ways that single cell and module lab cycling can be improved to better predict operation in fielded systems.In preparation for this deployment, SNL conducted single cell cycling experiments in the lab to simulate operation in the field and determine the expected life of the systems. The first test program utilized elements of the IEC 61427-1 standard for photovoltaic off-grid application to simulate the temperature and predicted state of charge (SOC) range the cells will be cycled during field operation. The simulated field cycling targeted SOC ranges of 10 to 40% and 80-100% over 150 cycles with temperature varied between -4 and 35oC to match the ambient conditions in the field during each season. The second type of cycling test was a temperature dependence study to determine how temperature impacted cell degradation. Cells were cycled at C/10 at their full SOC range and at a single temperature until they reached 40% capacity retention. Both cycling studies predicted that low temperature operation would increase the rate of degradation.The system was deployed in May of 2022, and since that time the SNL team has collected a significant amount of performance data to help analyze system level behaviors as compared to observations from cell level testing. These include battery interactions with the solar charge controller, limitations on power inverter settings, and variance between the average system level state of charge and the test protocol. Additionally, the team is analyzing conditions found in the field, with regards to ambient temperature, solar insolation and battery charging rates, and customer usage patterns for comparison with cell-level testing protocol.Observations of the deployed system’s performance indicate there is a need for more nuanced testing protocols for lab testing that can better approximate field conditions. These may include dynamic temperature ranges that vary throughout a charge/discharge cycle, and solar charging assumptions that account for reduced insolation due to cloud cover. This can help further inform the development of charge control algorithms, system hardware and software that can help improve the overall performance of solar microgrid energy storage systems.Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2023-02502A

Sizing and scheduling optimisation method for off-grid battery photovoltaic irrigation networks

An algorithm to optimise the number of solar panels and battery size to meet the water demands of an installation has been developed. The algorithm adjusts for seasonal changes in energy use and production in a pressurized irrigation network and production in an off-grid solar panel system. By using this algorithm, we aim to create an efficient and sustainable irrigation system by reducing the infrastructure and reliance on the power grid. This method can enhance irrigation systems in far-off regions, strengthen their endurance, and promote sustainable energy in farming and water administration.

Enhancing the Efficiency and Reliability of a Standalone Solar Energy System for Homes in Iraq

This study explores the knowledge regarding unconnected solar energy systems, their configurations, and the effects of Iraq's warm weather. Furthermore, it investigates the advantages and disadvantages of implementing such systems in Iraq. The research recognizes the efficacy of off-grid solar energy systems and their potential to provide clean electrical energy to meet the needs of Iraqi citizens while reducing harmful environmental emissions. The study employs an applied research project to assess the operational efficiency of off-grid solutions. The PVSYST application was used to simulate the solar energy system data. The research aims to develop off-grid solar energy systems, assess the suitability of building roofs, examine how heat affects panel productivity, and evaluate the impact of shading on energy levels, among other objectives. The study also covers the components of solar energy systems and how to assess their quality to withstand Iraq's typically hot climate.

Towards equitable and inclusive energy systems for remote off-grid communities: A socio-technical assessment of solar power for village Helario in Tharparkar, Pakistan

Universal access to clean electricity (SDG7) in remote areas of the rural South remains a key challenge for economic growth, and has particular implications for equitable, inclusive and sustainable development. In Pakistan, techno-economic constraints in grid expansion for last-mile users, combined with the country's high solar energy potential make off-grid solar energy generation a viable solution, provided its technological, social and economic implications are well-understood in terms of actual energy demands and designed for equitable distribution. This paper presents a socio-technical feasibility assessment for designing equitable and inclusive off-grid solar systems using the case-study of Helario village in Tharparkar, Pakistan, with a key focus on gender-specific benefits. A mixed-methods approach is used to conduct a baseline field assessment of existing energy sources, community needs, women's access and energy use, affordability, future energy aspirations and social acceptability of renewable energy technologies. Results indicate gendered differences in mobility, education, everyday practices and income that have socio-economic implications, whereby women can benefit more from electrification, particularly when electricity is interlinked with access to clean water. Results are used to model, simulate and optimise a solar-battery mini-grid system for tiered and equitable energy access using CLOVER. Analysis shows that a system designed with a 10-year lifetime provides the lowest levelised cost of electricity and minimum emissions intensity, emphasising the need for long-term energy system planning. This paper serves as a demonstration for policymakers, project developers and rural communities for designing more equitable and inclusive energy systems with clear gendered implications for sustainable future access.

Solar powering public health centers: A systems thinking lens

Around 300,000 women around the world die every year due to complications during pregnancy and childbirth. An estimated 19.9 million children do not receive critical vaccinations putting them at serious risk of potentially fatal diseases. These risks and deaths are preventable with appropriate management and care. Access to healthcare in low resource settings requires a comprehensive approach that strengthens infrastructure, systems, and medical and human resources. The lack of access to energy within infrastructure strengthening dramatically contributes to the immense healthcare challenge faced by developing countries. Electricity is essential for access to health services, as essential as the healthcare center, human resources, equipment, medicines etc. Universal Health Coverage cannot be achieved without energy access in healthcare facilities.Healthcare today, without counting the potential services to the un-catered populations in the world, contributes to GHG emissions, equivalent to the 5th most polluting country in the world. Furthermore, if we must meet the goals of access to health today, it cannot be considered via traditional models of electrification, keeping both the health of the people andthe planetary boundaries in mind. Clean energy and particularly solar energy, if planned and deployed in a manner that is decentralized, need-based along with accounting for local capacities and conditions for sustenance - can become a ‘silver bullet’ in catalyzing healthcare access to under-resourced settings. Given low-resource settings and last mile healthcare requirements this article only takes into consideration off-grid solar systems, which could be one of the primary ways for health centers to become resilient and contribute to climate mitigation, irrespective of prevailing grid and on-grid conditions.With multiple similar programs for solar powering public health facilities over the past decade there are learnings that emerge from across the globe. One of the key learnings is the need for a system thinking lens while deploying decentralized solar for health programs that sustain from a long-term perspective. Systems thinking is an approach that enables one to consider the health system as a whole, while designing demand driven solar powering programs for driving access to healthcare goals. This can be done by breaking down all aspects of solar powering and ensuring that within each aspect, the need is well-understood, the key stakeholders and their priorities are considered and capacities and relationships are accounted for. Moreover, systems are put in place for customization, expansion, and maintenance over time. The suggestions and examples provided below prioritize healthcare needs while driving enabling conditions for design and sustenance of solar for meeting current and future healthcare challenges. While healthcare systems require multiple levels of both curative and preventative healthcare, the considerations below are primarily for last mile public health curative infrastructure. Below, some best practices are elaborated across the following aspects for solar powering health:1. Assessment2. Technical Design3. Financials and Budgeting4. Procurement5. Operations and Maintenance6. Capacity Building

The Effect of Luminous Intensity, Humidity, and Temperature on The Output Voltage of Solar Panels

Solar Power Plant is a power plant by utilizing sunlight. In this study, the focus is on the use of off-grid solar power systems. The purpose of this study is to determine the effect of luminous intensity, humidity, and temperature on the output voltage of a solar power plant. The research method used is experimental. The maximum output voltage of the solar panel is 19.2 V obtained at 01.00 pm. During these conditions, the luminous intensity value is 121000 lux at an air humidity of 52.4% with a temperature of 40.50C. The results showed that (1) the greater the luminous intensity, the greater the output voltage of the solar panel. (2) If the greater the humidity, the smaller the output voltage of the solar panel. (3) If the greater the temperature, the greater the output voltage of the solar panel.

DESIGN AND ANALYSIS OF BUILDING CONSTRUCTION WITH EQUIPMENT GREEN ENERGY POWER PLANT BY HOMER METHOD

Technology has been able to make a power generation system by utilizing solar radiation into electrical energy in the form of PLTS (Solar Power Plant). This article aims to design an off grid PLTS Building and Equipment’s with a capacity of 88 kWp to meet the electricity needs of the people of Kogholifano Village, Pasir Putih District, Muna Regency. Analysis of the performance of 88 kWp off grid solar power plant in kogholifano village was simulated using Software HOMER. The design of the PLTS begins by analyzing the existing 40 kWp PLTS of Kogholifano village. The technical and financial performance of the 88 kWp off-grid solar system was simulated via HOMER. The results of the analysis show that this system will provide electrical energy supply with an operating time of 24 hours / day

Daily electrical energy consumption characteristics and design implications for off-grid homes on the Navajo Nation

Access to electricity remains elusive for over 700 million people worldwide. Although much attention has been given to solving this vexing problem in the context of communities in Sub-Saharan Africa and South Asia, often overlooked is that in even within so-called developed countries access to electricity might not be universal. It is estimated that more than 200,000 people living in North America do not have a connection to the electric grid. Many of these people live on Native American reservations or other Tribal Lands. Recently, there has been a concerted effort in the public, private, and non-profit sectors to electrify these homes with off-grid solar systems. This paper analyzes the electrical energy usage characteristics of 127 homes on the Navajo reservation in the southwestern United States. The homes have identical 3.8 kW solar arrays, 35.1 kWh 48 V gel lead acid battery banks, and 8 kW inverters. High-resolution inverter data was collected from these systems for a two-year period. Several statistical analyses were conducted on the data, including computing the statistical moments, creating empirical distributions of daily consumption, and analyzing consumption variation across different timescales. The results show average consumption of 2.78 kWh per day, but with a wide range of variation among homes. The implications of the analyses on pre-implementation system design, post-implementation interventions, and comparisons to incipient electricity consumption characteristics elsewhere in the world are discussed. The use of the average daily consumption in data-driven load estimation is evaluated and found to offer promising improvements over survey-based methods.

Emotional energy communities: Centering emotions and feelings within energy transitions in southern Mexico

Energy communities are key to understanding the drivers and impacts of energy transformations. However, research focused on profiling and evaluating energy communities has often overlooked the fundamental role of emotions and emotional processes during energy transitions. To address this, our article draws together the Latin American concept of ‘emotional communities’ with the prevailing European concept of ‘energy communities’; resulting in an enriched term of ‘emotional energy communities’ in which the emotional dimensions of energy are centered. Looking at two previously non-electrified multi-ethnic communities in the south of Mexico, we identified three crucial energy moments: a) living without electricity; b) counting on electricity produced by off-grid solar systems, and c) returning to living without electricity but now with the knowledge of what electricity enables. We retrospectively explored the emotions associated with these three energy moments via in-depth interviews and focus groups, finding that electrification was an inflection point for these two communities. The solar interventions generated new identities, and a range of positive and negative emotions, which fluctuated over time and varied by factors such as gender, age, and ethnicity. By looking at emotional processes, rather than singular emotional states, we were able to conduct a more complex analysis of both individual and community-level lived experiences and the impacts of energy interventions. In doing so, we highlight the importance of considering emotions within energy studies, as well as the need to look beyond households as a unit of analysis, particularly outside of westernized contexts where public and private spheres are blurred.

Off-grid solar photovoltaic-alkaline electrolysis-metal hydrogen storage-fuel cell system: An investigation for application in eco-neighborhood in Ningbo, China

This study proposes a combined hydrogen, heating and power system based on solar energy for the off-grid application of distributed renewable energy. With hydrogen as the energy carrier, the stable consumption of renewable energy can be achieved by integrating alkaline water electrolysis (AWE), metal hydride (MH) hydrogen storage, and proton exchange membrane fuel cells (PEMFCs). An energy management strategy is proposed based on the coordinated control of mass, energy, and information flow. Fluctuations in multi-source heat flow during solar photovoltaic (PV) power generation, hydrogen production, hydrogen-storage, and PEMFC power generation were studied based on electric and heating loads of typical winter and summer days in an eco-neighborhood in Ningbo, China. Owing to differences in solar radiation between summer and winter, the total electric energy generated by PV panels was 6179 kWh and 3667 kWh for summer and winter, respectively. The start-up times for AWE and MHs were 0.92 h and 0.32 h in summer and 1.70 h and 0.55 h in winter, respectively. After one day of operation, the hydrogen and heat surpluses were 57.17 kg and 5735.83 MJ in summer, while in winter the hydrogen surplus and heat deficit were 30.87 kg and 226.41 MJ, respectively.

Techno-economic optimization of hybrid solar system with energy storage for increasing the energy independence in green buildings

The optimal design and optimization of the hybrid renewable energy system powered by photovoltaic panels (PV) with appropriate backup energy storage is the essential for increasing the energy independence in green buildings. This paper designs and compares hybrid PV panel with two main energy storage systems in remote areas (PV/battery and the off-grid PV/hydrogen system). These hybrid renewable energy systems are capable for producing steady output to the grid at the least total annual cost (TAC) of system, with maximum acceptable lack of power supply probability. A particle swarm optimization (PSO) has been developed using MATLAB to optimally design a hybrid PV/battery/hydrogen system. To confirm the superiority of the PSO method, the optimization problem was implemented in 1 to 30 independent executions and the best result was reported. Actual meteorological data in China is selected to test the concept of the off-grid solar energy system. The effect of changes in system reliability, number of run, and interest rate on the design results of two systems are compared and analyzed. The research found that the PV/battery system in remote areas becomes more economical than the off-grid PV/hydrogen system as reliability decreases and interest rate increases. Also, the total configured capacity of solar panel in the PV/battery structure is smaller (by 44.8 %) than that of the PV/hydrogen structure. Moreover, with the increase of number of run from 1 to 20, the number of components, in the PV/hydrogen system is adjusted to decrease the TAC (by 2.2 %), and the TAC of the PV/battery also decreases by 0.23 %.

Solar Radiation Forecasts and a Tiny House PV Off-Grid System

In this article, which is discussed at a time when initiatives towards renewable energy sources are increasing and reducing fossil fuel consumption; the factors that need to be examined for the installation of an off-grid solar panel system were examined and in line with the data obtained, a system was designed for a tiny-house. An off-grid system with 10KWh power consumption with optimum irradiance data has been found on how many square meters of PV system will be needed to operate it. How to meet the stable 10KWh need for the worst month, the amount of battery capacity required has been examined. A system inventory has been allocated. The province of Pamukkale in Turkey, with a latitude of 37.89°, was chosen for the solar panel installation; It is aimed to meet all the electricity needs of the house, which was built in a forest area 8 km away from the mains, with the solar panel system to be installed. From theory to practice with an academic approach as well as solar energy sector jargon; in this article, includes a two-way study. A solar panel system was installed in line with the data obtained and the 7600Wh value that the house to be built would need, and 29 batteries integrated into the system were sized for cases where the system could not provide sufficient energy through the sun with a 1% probability. Thus, the design of the optimum "Solar Energy System" desired for a certain location and compatible estimation calculations will be able to provide examples of this study.

Desempenho econômico de sistemas fotovoltaicos off-grid para irrigação

ABSTRACT Renewable energies are alternatives to replace fossil fuels and are crucial for the sustainability of the agricultural sector, besides being an important alternative for pumping water in irrigation. Thus, understanding revenues and expenses is fundamental in economic feasibility. Therefore, the aim of this study was to assess the behavior of economic indicators in off-grid solar energy system for irrigation based on different scenarios. Photovoltaic projects were developed for different irrigation powers ranging from 0.736 to 22.1 kW, and the costs for implementation and operation, as well as the occurrence of economy of scale were evaluated, and the levelized cost of energy for each power analyzed was determined. In addition, sensitivity analyses were performed, considering the variation in product price and investment cost, to demonstrate the responses in relation to economic indicators. Photovoltaic energy projects showed increasing costs with the increase in power, and the normalized cost per kW followed an economy of scale, while the levelized cost of energy showed feasibility, except for the power of 22.1 kW. The sensitivity analyses showed profitability for the analyzed configurations.