Photovoltaic Irrigation Research Articles

Solar PV and canal irrigation financing: Leveraging energy cash flow for sustainable agriculture

This research paper explores the innovative financing model for integrating Solar Photovoltaic (PV) systems with canal irrigation infrastructure. The focus is on utilizing energy cash flow generation to fund these sustainable projects. The study investigates the potential benefits, economic feasibility, and environmental impacts of this model, particularly in regions with extensive canal networks and high solar insolation. A specific case study of the Siret-Bărăgan irrigation canal in Romania, powered by floating photovoltaic systems, is analysed in detail. This study explores the feasibility and benefits of financing the Siret-Bărăgan irrigation canal in Romania through the integration of floating Photovoltaic (PV) systems. The project aims to address water scarcity, enhance agricultural productivity, and promote sustainable energy production. By leveraging green bond financing, the initiative proposes a financially viable and environmentally sustainable solution to Romania’s irrigation and energy challenges. The paper presents an in-depth analysis of the project’s technical, economic, and environmental aspects, underscoring its potential as a model for similar projects globally.

In Situs Efficiency of a Direct Coupled Photovoltaic Irrigation System in Rural Niger, Input Current Oversizing Effect on The Pump Efficiency

A photovoltaic irrigation system, an excellent example of the water-energy-food nexus, is a suitable system for farmers in the semi-arid countries of the Sahel. These systems align with UN Sustainable Development Goals (SDGs), addressing food security, water access, and sustainable energy. However, their efficiency depends on mastering configuration, installation, and operation, crucial for resource conservation and optimal performance. This study evaluates a direct-coupled PVWPS in rural Niger found the PV array was oversized by double. Indeed, exceeding pump manufacturers' specifications by increasing PV array capacity didn't notably improve performance but decreased pump efficiency. For instance, with a 1.5 kWp PV array, the pump flow rate reached 3.5 m3/h. Doubling (100% increase) the PV capacity to 3 kWp marginally increased the maximum flow rate to 4.2 m3/h, yielding only a 20% water flow increase. This underscores the importance of appropriately sizing PV arrays to avoid diminishing returns. These findings are crucial for decision-making in designing and implementing sustainable photovoltaic water pumping systems. Optimizing PV array configuration based on pump specifications can enhance system efficiency and longevity, advancing sustainability goals while conserving resources

Feasibility analysis of photovoltaic systems for kiwifruit irrigation: A case study in Shaanxi province, China

AbstractAlthough photovoltaic (PV) irrigation systems are widely used in China, feasibility assessment of these systems is important because of differences in the distribution characteristics of solar resources and crops. In this study, kiwifruit planting in Shaanxi province was considered, and a calculation model for PV irrigation system evaluation was developed. Based on the geographical distribution of kiwifruit planting, as well as the spatial and temporal distributions of solar energy in Shaanxi province, the application potential of PV irrigation for kiwifruit was investigated comprehensively from the perspectives of technology, economy and irrigation feasibility. The results showed that the proportion of the PV module scale to the irrigation scale in all the kiwifruit planting areas in Shaanxi province was far less than 1.5%, and there were no technical obstacles. In Baoji, Weinan, Hanzhong and Ankang, the annual cost of the PV irrigation system was greater than that of the diesel pump irrigation system. Regarding irrigation feasibility, farmlands with a slope of 0%–8.75% were considered highly suitable for installing a PV irrigation system. The results revealed 32,269 ha of farmland appropriate for PV irrigation among the 66,371 ha of kiwifruit in Shaanxi province.

Unveiling the nexus between solar energy adoption and crop farmer income: evidence from Pakistan

Worldwide, the continuous advancement of off-grid solar photovoltaic irrigation seeks to improve water access, increase food production, and reduce carbon emissions and energy costs associated with fuel usage. Consequently, this enhances human resilience to climate change and contributes to the improvement of farmers’ income. This study investigates the influence of solar energy adoption on farmers’ income, drawing insights from 1,080 growers in Pakistan. It uses the logit model and propensity score matching (PSM) to address bias. Factors influencing income, including gender, education, decision-making autonomy, farm size, extension services, cooperative associations, access to credit, risk perception, market distance, and tube well availability, are identified. Findings reveal a positive correlation between solar energy adoption and increased crop farmer income. PSM analysis validates this, emphasizing the need for government and agricultural extension interventions to enhance financial accessibility for farmers facing mobility challenges. This includes subsidies for technology adoption and knowledge dissemination about digital technology. The study advocates for an accelerated adoption of solar energy to foster agricultural development in Pakistan. In resource-poor nations like Pakistan, government subsidies are crucial to offset technology costs for citizens facing challenges in affording green energy. Addressing Pakistan’s energy crisis through promoting solar energy for irrigation can amplify farmers’ income. It is imperative to promote access to this technology, particularly for water pumping, through subsidies and readily available credit facilities, given the resource limitations and small landholdings of many farmers in Pakistan.

Effect of Irrigation Interval on Growth and Forage Yield of Maize (Zea Mays) Variety Using Solar Photovoltaic Irrigation system in Sokoto, Nigeria

Experiment was conducted at the Usmanu Danfodyio University Dryl and Teaching and Research Farm (130 01 N and 50 13 E), during 2022 dry seasons. The objective of the research was to study the effect of irrigation interval on the growth and forage yield of cowpeas varieties using Solar PV Irrigation system. (SAMMAZ 15, SAMMAZ 33 and Ex Dundaye) respectively, with irrigation intervals of 3, 4 and 5 days respectively were used for the experiment. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Results from the research shows that variety had significant effect on stand establishment count, leaf length, leaf with, number of leave per plant, days to 50% tas selling and forage yield. Also, irrigation interval had significant effect on plant height, number of leaves, leaves length, days to 50% tasseling and forage yield. Interaction effects between variety and irrigation interval was also found to be significant. From this research, it was found that production of SAMMAZ 15 with 3 days irrigation interval is encouraged in Sokoto ecological condition using Solar PV irrigation system.

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.

An Automatic PI Tuning Method for Photovoltaic Irrigation Systems Based on Voltage Perturbation Using Feedforward Input

This paper proposes a new automatic tuning method for the proportional-integral (PI) controllers of photovoltaic irrigation systems (PVIS) without the need for any other power source or batteries. It enables the optimisation of the values of the PI parameters (Kp and Ki) automatically, eliminating the requirement for skilled personnel during the installation phase of PVIS. This method is based on the system’s voltage response when a disturbance signal is introduced through the feedforward input of the PI controller. To automatically assess the response properties, two indicators are proposed: the total harmonic distortion (THD), used to evaluate the sine response, and the total square distortion (TSD), used to evaluate the square response. The results indicate that the tuning changes for different irradiance and temperature conditions due to the non-linearity of the system, obtaining the most conservative values at maximum irradiance and temperature. The robustness of the results of the new automatic tuning method to abrupt photovoltaic (PV) power fluctuations due to clouds passing over the PV generator has been experimentally tested and the results show that the obtained tuning values make the PVIS stable, even when PV power drops of 66% occur abruptly.

Solar irrigation in sub-Saharan Africa: economic feasibility and development potential

Irrespective of water resource abundance, agriculture in sub-Saharan Africa (SSA) is predominantly rainfed. Along with fertilization, irrigation could support smallholder farmers with stabilizing crop yields, increasing incomes, and achieving food security. A key barrier to irrigation uptake is inadequate rural electricity supply for pumping and distributing water, besides other infrastructure deficits. Here we devise a spatially explicit integrated modelling framework to show that over one third of unmet crop water requirements of 19 major crops in smallholder cropland of SSA could be supplied with standalone solar photovoltaic (PV) irrigation systems that can be paid back by farmers within 20 years. This accounts for 60 km3 yr−1 of blue irrigation water requirements distributed over 55 million ha of currently rainfed harvested area (about 40% of the total). Crucially, we identify 10 million ha with a profit potential >$100 ha−1 yr−1. To finance such distributed small-scale infrastructure deployment and operation, we estimate an average discounted investment requirement of $3 billion yr−1, generating potential profits of over $5 billion yr−1 from increased yields to the smallholder farmers, as well as significant food security and energy access co-benefits. We demonstrate the critical importance of business models and investment incentives, crop prices, and PV & battery costs in shaping the economic feasibility and profitability of solar irrigation. Yet, we find that without strong land and water resources management infrastructure and governance, a widespread deployment of solar pumps may drive an unsustainable exploitation of water sources and reduce environmental flows. Our analysis supports public and private stakeholders seeking to target investments along the water–energy–food–economy–sustainable development nexus.

Experimental Performance Evaluation of a PV-Powered Center-Pivot Irrigation System for a Three-Year Operation Period

High-power diesel-based or grid-connected irrigation systems are being replaced by battery-free, high-power stand-alone Photovoltaic Irrigation Systems (PVIS) that reduce energy costs by up to 80% and for which no experimental performance data are available. The operation of PVIS is affected by various factors, some unrelated to the quality of the PV system itself, that generate losses that affect their performance: losses that vary with the crop and its irrigation period, losses intrinsic to the PVIS design, and losses that happen as a consequence of the behavior of the end-user. To better understand the impact of each type of loss, the traditional performance ratio was factorized. This paper provides the PV community with experimental data on the performance of a battery-free 160 kWp PV-powered constant-pressure center-pivot irrigation system. The system was analyzed over three years of real operation, during which the performance ratio ranged from 49.0 to 53.2%.

Decision Support Tool for the Optimal Sizing of Solar Irrigation Systems

Solar photovoltaic (PV) irrigation is increasingly used in agriculture, driven by its low operation cost and virtually zero emissions, providing electricity access in rural areas. However, the high investment cost requires an optimal design. The objective of this work was to develop a user-friendly tool to optimally size a PV generator that satisfies crop irrigation needs under local constrictions. The ODSIS (Optimal Design of Solar Irrigation System) tool, was organized in three calculation modules, preceded by two complements, which determine the daily crop irrigation needs and power demand of the pumping system. Then, the first module sizes the PV plant, considering a multiplication factor, and provides the PV production potential throughout each day of the season. The second and third modules evaluate the total investment cost and equivalent greenhouse gas emissions avoided by comparison with traditional energy sources. This tool was applied to a case study in Senegal for which a multiplication factor of 1.4 was obtained for the optimal PV plant size. Between 22% to 64% of the investment cost corresponded to the PV pumping system, depending on the irrigation technique. The use of PV energy in the case study would represent an annual economic saving for the farmer after 5 to 8 years of payback period, avoiding the emission of between 29.8 and 37.9 tCO2eq/year for the case study area.

Performance analysis of polycrystalline floating photovoltaic array: The concept and prototype development for irrigation purpose

AbstractThe concept and design of the 2 kWp polycrystalline floating photovoltaic (PV) system for agricultural irrigation purposes are presented in this paper. The well‐known major advantage of the floating PV system is its installation in the presence of water, which leads to cooling of the PV system that improves its efficiency. In addition to that, the floating PV system reduces the wastage of cultivation area required for its installation, and also, it reduces evaporation of water (for 20% of float cover) by the factor of 22.23 cm/year. But the floating PV systems face some confrontations such as low electrical reliability and reduced life of the mechanical structure due to nearby water surface. As an attempt to overcome the above issues, a small‐scale floating PV system prototype in a water reservoir at Kothavadi village, Tamil Nadu, India has been developed. The system comprises of a floater, mechanical structure, PV module, supporting anchor, under water cable, and motor. The power generated out of this proposed system is utilized for pumping the water from a nearby bore well, and pumped water is stored in the same reservoir where the floating PV system is installed. The water in the reservoir can be used by the farmer for their necessity. In this study, the energy production (month by month) is monitored. Furthermore, the economic analysis and PV modeling have been performed along with some maintenance aspects. The study helps the scientists and engineers to comprehend the performance and commercial viability of floating PV for rural farmers. It is anticipated that this work will inspire and direct farmers to install a floating PV irrigation system as a perfect alternate for the conventional systems.

A New Strategy for PI Tuning in Photovoltaic Irrigation Systems Based on Simulation of System Voltage Fluctuations Due to Passing Clouds

One of the greatest challenges in stand-alone photovoltaic irrigation systems (PVIS) without batteries is the tuning of PID controllers and the evaluation of their performance once the system is tuned. Tuning method must be applied in clear days (constant irradiance) while performance must be evaluated in the most unfavourable circumstances, which occur when the passage of a cloud causes a sudden drop in available power. In short, tuning and testing must be done under different weather conditions. To solve this problem, a tuning method that is complemented by a method to simulate voltage fluctuations due to cloud passage has been developed. This allows tuning and evaluation of the system’s performance in the same session. Furthermore, the new PI tuning method achieves a better adjustment of the parameters and solves the instability problems that arise when applying traditional closed-loop tuning methods. Both methods use the feedforward input that most variable frequency drivers have. A signal generator is used to carry out the simulation of the clouds. This input is also used to introduce a triangular signal used for the tuning of the PI controller. The results show that the performance of the system, characterized by the voltage of the PV generator, with simulated clouds is similar to the response with real clouds. With regard to the tuning, the new method achieves better performance than previous methods. These methods can be applied on clear days, under conditions of constant irradiance, which greatly simplifies its implementation and greatly reduces the time required for commissioning the system.

Modeling and Simulation of Multipumping Photovoltaic Irrigation Systems

The growing market of large-power photovoltaic irrigation systems (PVISs)—made of systems with different and several motor pumps working in parallel—needs simulation tools capable to estimate their energy and water productivity. The objective of this paper is to present the simulation models developed for parallel multipump PVISs fed by a single PV generator. These models seek to maximize the instantaneous water flow rate according to the available PV power and were developed for the typical configurations of large-power irrigation facilities. The models present some advantages when compared with the current state of the art (in which a single motor pump connected to a 1/N fraction of the PV generator is simulated and the result is multiplied by N): in the case of negligible hydraulic friction losses, the use of the multipump model shows gains with respect to the state of the art; in the case of appreciable friction losses, the current state of the art overestimates the productivity of the systems. Then, the ability of these models to compare different multipump designs is shown: two groups of pumps working at variable frequencies show better performance than a group working at a variable frequency and a group at a nominal frequency—an 8% increase in the water pumped is seen.

A Blockchain-Based Financial Instrument for the Decarbonization of Irrigated Agriculture

Farming and food production sustainability increasingly depends on the availability of a clean energy model for irrigated agriculture. This can be achieved by massively introducing photovoltaic irrigation systems (PVI) with sufficient quality and reliability. Nevertheless, such PVI projects require high upfront investment and long payback times, so access to long-term, low-cost capital is essential to ensure their competitiveness. In this regard, decentralized financial (DeFi) solutions based on blockchain (BC) technology present a number of features that can be applied to produce financial instruments (FI) well suited to attract investors to PVI projects and to reduce the cost of clean energy for irrigators. In order to assess such a possibility, a DeFi FI tailored for PVI has been produced and implemented in BC. We demonstrate that a single smart contract executed in a distributed ledger can execute the different tasks related to the securitization of PVI assets. The impact on the cost of capital for PVI projects is significant, leading to an estimated reduction in the cost of clean energy for irrigators of 22%. Nevertheless, decentralization also introduces a number of specific risks that must be considered and mitigated.

Methodological Advances in the Design of Photovoltaic Irrigation

In this study, an algorithm has been developed that manages photovoltaic solar energy in such a manner that all generated power is delivered to the system formed by a pump and irrigation network with compensated emitters. The algorithm is based on the daily work matrix that is updated daily by considering water and energy balances. The algorithm determines an irrigation priority for the sectors of irrigation of the farm based on programmed irrigation time and water deficits in the soil and synchronises the energy produced with the energy requirement of the hydraulic system according to the priority set for each day, obtaining the combinations of irrigation sectors appropriate to the photovoltaic power available. It takes into account the increment/decrease in the pressure of the water distribution network in response to increases/decreases in photovoltaic energy by increasing/decreasing the rotational speed of the pump, thus increasing/decreasing the power transferred to the system. The application to a real case of a 10-hectare farm divided into four sectors implies an efficient use of the energy of 26.15% per year and savings in CO2 emissions of 6.29 tonnes per year.

Photovoltaic Direct Drive Water-saving irrigation System and Its Optimization Design Method

Photovoltaic irrigation has been widely used in many areas without conventional energy sources. In order to solve the problem of unstable operation and poor irrigation uniformity caused by the diurnal variation of solar radiation, a photovoltaic direct-drive water-saving irrigation system with automatic regulation was proposed. By using automatic control technology and the method of zonal rotation irrigation, all the electric energy generated by solar panels can be converted into irrigation energy under different light intensities, so that the water-saving irrigation equipment can work stably in different regions and the irrigation uniformity is ensured in different regions. According to the characteristics of solar energy resources and photovoltaic water-pumping units, the optimum design method of photovoltaic water-saving irrigation system is put forward. The minimum capacity of solar panels can meet the irrigation demand of a certain area, which can guide the engineering design of solar water-saving irrigation, greatly improve the engineering quality and energy utilization rate. It has the advantages of simple design, low cost, stable operation and energy-saving ring.

Solar for all: A framework to deliver inclusive and environmentally sustainable solar irrigation for smallholder agriculture

Worldwide, off-grid solar photovoltaic irrigation is currently being developed with the expectation that it will help secure water access to increase food production, reduce fuel-based carbon emissions and energy costs, and increase human resilience to climate change. In developing countries across the Middle East and North Africa, South East Asia and Sub-Saharan Africa, the adoption of solar technology in agriculture to lift groundwater is rapidly expanding, following decreases in pump costs, economic incentives, and development partner initiatives. Solar irrigation potentially provides a cost-effective and sustainable energy source to secure food production and sustain livelihoods in line with multiple Sustainable Development Goals, but achieving such potential requires improved policies and institutions to coordinate across numerous stakeholders, objectives, and approaches. This paper uses cases and observations from across regions to propose a framework to support policy, regulation, and monitoring for environmentally sustainable and socio-economically inclusive solar irrigation investments. While not exhaustive, the components seek to address the intersection of energy, water and food security, as well as social equity. The paper emphasizes the need for an understanding of how solar irrigation can be scaled to be both accessible for smallholder farmers and environmentally sustainable.

Automatic irrigation monitoring system based on photovoltaic solar energy with fuzzy logic

Indonesia’s food self-sufficiency program requires the use of paddy fields with rice as the main food. That irrigation infrastructure problem also needs efficiency mitigation of cost impact using fuel oil in operation manually of engine irrigation. An automatic photovoltaic irrigation system can solve the problem of deficiency irrigation infrastructure, especially in the dry season as a more efficient power supply for irrigation infrastructure. In this research, implemented the automatic photovoltaic irrigation system is combined with the sunlight tracking system to get power supply, according to the direction of the sun. The irrigation pattern requires the suitability of soil moisture, water level, and power supply voltage as variables for the application of an automatic photovoltaic irrigation system. An automatic photovoltaic irrigation system is equipped with a website to monitor the irrigation variables. The Irrigation variables data is obtained from sensor readings then sent by NodeMCU to the website and calculates the suitability of irrigation variables as parameters using fuzzy logic to control automatic irrigation. The conclusion from this study was obtained after testing the system with the system running well, fuzzy logic parameters run with variables value of voltage > 9.9 Volt, water level < 2cm, and soil moisture < 69%.

Optimal Design of Photovoltaic Irrigation System with Different Nozzle Numbers

HighlightsWhen the photovoltaic irrigation system is loaded with different numbers of nozzles, the working pressure of the nozzle will change. This is because the pipeline characteristics have changed with the variation of nozzle number. So the pump operating point changes and its head will also change, which leads to the change of working pressure of nozzle. To solve this problem, by theory analysis based on the test results, it is feasible to make the pump flow rate/head curve flatter. In this case, when the system pipeline characteristics change, the pump head changes little.This article presents a new optimization method to improve the performance of photovoltaic irrigation systems under variable load. The method just needs to optimize the four pump impeller structure parameters, which can make the pump flow rate/head curve flatter. So the pump head changes a little when the system is loaded with different numbers of nozzles, which can make the working pressure of the nozzle stable and improve the system performance.Taking the slope of flow-head curve as the optimization objective, and the impeller blade outlet angle ß2, blade outlet width b2, blade number Z, and rear cover diameter D2min as the optimization variables, the performance of the photovoltaic irrigation system is optimized by orthogonal test design optimization scheme. After optimization, when the system is loaded with a different number of nozzles, it can provide relatively similar pressure under different ranges of light intensity.Abstract. The performance of the photovoltaic irrigation system under variable load were obtained and analyzed through test measurement. The adaptability of the system under variable load could be improved by optimizing the pump impeller structure, and then the irrigation uniformity of the photovoltaic irrigation system under different loads could be improved. Taking the slope of flow-head curve as the optimization objective, and the impeller blade outlet angle ß2, blade outlet width b2, blade number Z, and rear cover diameter D2min as the optimization variables, the performance of the photovoltaic irrigation system is optimized by orthogonal test design optimization scheme and the test verification was carried out. The range method was applied to analyze the simulation results. It can be found that when the geometric parameters of the impeller are D2 = 86 mm, ß2 = 41°, b2 = 4.0 mm, and Z = 9, the slope of the pump flow-head curve is the highest. The system performance after optimization was measured and compared with the original scheme. By comparison, it was drawn that when the system is loaded with different numbers of nozzles, the nozzle pressure can be maintained near the optimal pressure of the nozzle within a wider light intensity. After optimization, when the system is loaded with a different number of nozzles, it can provide relatively similar pressure under different ranges of light intensity. Keywords: Nozzle, Orthogonal test, Optimal design, Photovoltaic irrigation, Pump.

Designing an irrigation system using photovoltaic energy by considering crop type in Fergana Valley

Today, the importance of energy cost and efficiency is gradually increase. The decrease in drinking water and agricultural water resources, increases the interest in drip irrigation systems in agricultural irrigation. Environmentally friendly photovoltaic drip irrigation systems (PVDIS) are the appropriate solution in regions where there is no electricity distribution network, where it is far away, or where power cuts are frequently. This study is carried out in the Fergana Valley of Uzbekistan. Regional climate data obtained from Climwat 2.0 software are processed in Cropwat 8.0 software. Crops that are both the source of livelihood of the people of the region and that can be used in this study have been determined. Annual and daily water needs are analyzed so that these crops are irrigated every seven days. A system is designed by taking the data of the crop with the highest water requirement as a reference. The drip irrigation system is set up in a PVsyst 7.1.7 simulation environment to pump 114.24 m3 of water daily from a 5-meter-deep river with a 1.8 kW photovoltaic system. The efficiency of the system is 58.7% and the efficiency of the pump is 34.5%. Crop water need is met at the rate of 98.87%. It is predicted that the designed and analyzed PVDIS will provide efficiency in energy and water resources.