Explore the vast range of titles available.

Solar powered irrigation pumps (SIP) hold substantial potential for low carbon irrigation expansion, particularly where affordable electricity is limited. In contrast to diesel-based irrigation, which carries steep fuel costs, irrigation by SIP requires zero marginal costs, but high initial investments. This makes their competitiveness with diesel pumps highly dependent on the temporal frequency of their usage. Using unique and detailed data on SIP usage by smallholders in Nepal, we show SIP usage frequency is low, making it financially competitive with diesel for only a small fraction of farmers. We analyze characteristics of farmers who make low/high usage of the SIP, and explore potential explanations for the puzzling low level of SIP use.

Solar irrigation pumps (SIPs) are central to Nepal’s strategy for sustainable irrigation and reducing reliance on diesel pumps. The Alternative Energy Promotion Centre (AEPC) officially provides a 60% subsidy for SIPs under a demand-driven program. This study assesses (i) SIP subsidy delivery and adoption processes, and (ii) utilization patterns and their drivers, using a household survey of 630 farmers and a phone survey of 404 SIP owners. In practice, farmers contributed only 4% of total SIP costs on average, as local governments frequently topped up AEPC’s subsidy, making SIPs nearly free. While this boosted affordability, the scheme is only weakly progressive: large farmers also benefit from near-complete subsidization, raising equity and fiscal concerns. The applicant pool is dominated by educated, wealthier, and socially advantaged groups, while marginalized farmers are often excluded due to weak information and institutional gatekeeping. Utilization is moderate, with SIPs operating around 745 h annually—well below their technical potential. Breakdowns, long repair delays (averaging 110 d), and missing after-sales services reduce use. Training in operation and maintenance increases utilization by 38%, while cultivation of water-intensive crops also drives higher use. Transparent communication of the full subsidy package, progressive cost-sharing to prioritize smallholders, and stronger investment in training and rapid-repair services are essential. Without such reforms, the program risks under-utilization and elite capture of subsidies, undermining SIPs’ transformative potential for agricultural resilience and low-carbon growth.

One of the most serious problems among smallholder farmers in South and Southeast Asia associated with the use of a surface water irrigation pump is low engine performance. The main cause of this low performance is the decrease in the flow field energy conversion mechanism caused by irreversible processes. The energy conversion theory suggests that pump efficiency is maximum when the loss is minimum. Whatever the origin of the losses, the deterioration in engine performance is due to a deterioration in the reversibility of the pump system. In this study, the pump is classified as the propeller impeller (PI), the improved axial or typical impeller (TI), and the conical hollow-shaped impeller (CI). Entropy production is applied to the pump on design improvement and loss sources location and mechanisms. The entropy production consists of viscous dissipation and turbulent dissipation. In this study, the pump design improvement of various designs based on entropy production has been studied in detail to predict energy loss in areas such as the inlet section, impeller, or discharge pipe. With the entropy generation, the optimum efficiency of different pump designs CI, PI, and TI were determined. The results showed that in all designs, more than 63% of the total entropy generation came from turbulent distribution. The flow in the pumps was analyzed in detail in comparison with entropy generation. It was found that the entropy generation rate increased in the secondary flow direction and was consistent with free-stream velocity. The PI design at the inlet pipe should be modified for reducing flow separation and entropy generation. All design impellers showed high energy losses, especially near the hub and tip along the leading edge and trailing edge. Therefore, it is possible to determine which features of the flow and entropy generation are relevant to the pump improvement.

This study examines the socioeconomic and behavioral determinants, together with spatial heterogeneity, influencing the adoption of solar irrigation pumps in Bangladesh. Five study regions of Bangladesh were sampled using stratified random sampling to collect 257 respondents, who were familiar with both solar and diesel pumps, to justify the energy transition, ensuring sample equity throughout the regions. Income inequality among respondents was assessed using the Lorenz curve, revealing that the bottom 50% of respondents only earned 20% of total income, while a Gini coefficient of 0.46 indicated moderate to high income disparity. To determine whether socioeconomic factors and spatial heterogeneity significantly influence adoption decisions, a Firth’s penalized likelihood logistic regression model was employed, complemented by predictive and average marginal effects for regional categories. The results identified that training, social influence, large household size and income are the prominent drivers for solar pump adoption. Based on the significant spatial heterogeneity, we further recorded a five-point Likert scale response to design region-wise policy recommendations for the fast diffusion of solar pumps. Financial incentives emerged as the most critical policy lever, with 89.10% of respondents expressing strong agreement and a mean score of 4.83. Overall, these findings highlight the central role of socioeconomic and spatial factors in shaping adoption behavior and suggest that policy interventions should prioritize targeted financial and technical support to promote the equitable and rapid diffusion of solar irrigation technologies.

The climate-friendly solar-powered irrigation pump is expected to reduce the exploitation of groundwater, save electricity costs, and increase income for farmers. It is also expected to reduce global warming by reducing CO, emissions, etc. Therefore, solar-powered irrigation pumps have been promoted with an attractive subsidy scheme by the government of India. Though the adoption of solar pumps has been increasing at a faster pace in recent years, the intensity of adoption of such pumps is not appreciable in many states in India. Since the adoption of solar pumps is still in a nascent stage, an attempt has been made in this study to find out the determinants of the adoption of solar pumps using both macro and micro-level data. While the macro-level analysis was carried out using the data of 17 major states, the micro-level analysis was carried out using survey data collected from 304 sample farmers belonging to four districts of Tamil Nadu. The multiple regression analysis carried out covering data from major states shows that the electricity tariff rate influences the adoption of solar pumps positively and significantly, while the share of the non-foodgrains area to the cropped area determines its adoption negatively and significantly. The logit regression results estimated by using field survey data suggest that the education of the farmer, cropping intensity, and farm size are more likely to influence the adoption of solar irrigation pumps.

The development of renewable energy-based applications is nowadays a forced demand of society, for chasing the target set by the governments and the concerned organizations, to reduce or limit the carbon penetration in the environment. Sincere efforts are being made by academics and researchers to create applications based on renewable energy that are reliable and efficient. Green revolutions increase agricultural fields and alter grain production rates, but they also increase energy consumption since agricultural machinery is used more efficiently, mostly for irrigation needs. The purpose of this work is to introduce a hybrid renewable energy system (HRES) that can take the place of the diesel pump often used for time-bound crop irrigation. This HRES system consists of a photovoltaic generator as the main power source supported by a battery energy storage system. For this hybrid system, the development of a Proportional & Integral (PI)-based integrated hybrid controller is proposed to regulate the charge/discharge cycle of the battery energy with maintaining the load demand simultaneously. Controlling of this hybrid system is carried out in the LabVIEW environment.

India is the world’s largest user of groundwater for irrigation, with approximately 32 million pumps running on diesel, electric, and solar power. Subsidized electricity has led to an increase in the adoption of electric pumps by farmers, with increasing electrification rates and rising diesel costs contributing to the trend. Government subsidies have been instrumental in enhancing smallholder irrigation pump access. However, subsidies on irrigation pumps may exacerbate undesirable groundwater depletion. In smallholder settings where the capital needed to purchase irrigation equipment exceeds farmers’ means, “irrigation-as-a-service” and “rental pumps” with organized and affordable volumetric pricing could offer viable solutions. This policy brief provides key learnings on the Indian irrigation pump market and its policy and environmental implications, based on semi-structured interviews and secondary data collected.

Centrifugal irrigation pumps in Southern Xinjiang face severe performance degradation due to high fine-sediment loads in canal water. This study combines Eulerian multiphase simulations with experimental validation to investigate the coupled effects of sediment size (0.05~0.8 mm) and concentration (5~20%) on hydraulic performance. Numerical models incorporating Realizable k–ε turbulence closure and discrete phase tracking reveal two critical thresholds: (1) particle sizes ≥ 0.4 mm trigger a phase transition from localized disturbance to global flow disorder, expanding low-pressure zones by 37% at equivalent concentrations; (2) concentrations exceeding 13% accelerate nonlinear pressure decay through collective particle interactions. Velocity field analysis demonstrates size-dependent attenuation mechanisms: fine sediments (≤0.2 mm) cause gradual dissipation via micro-scale drag, while coarse sediments (≥0.6 mm) induce “cliff-like” velocity drops through inertial impact-blockade chains. Experimental wear tests confirm simulation accuracy in predicting erosion hotspots at impeller inlets/outlets. The identified synergistic thresholds provide critical guidelines for anti-wear design in sediment-laden irrigation systems.

Bangladesh is the most densely populated country in the world. With a total population of around 165 million, the country has constantly been facing food security challenges and other problems. Therefore, increasing food production is one of the feasible solutions to this challenge, and proper agricultural land use for food production bears critical importance. Adopting sustainable irrigation systems and viable technologies would be vital for ensuring efficient use of agricultural land in Bangladesh to safeguard the country's food security. Solar irrigation pumps (SIPs) can be a reliable option in this regard. However, Bangladesh has experienced a prolonged growth rate of SIP installation in the last decade.  The countryhas set a target to install 10000 SIPs by the year 2027, albeit it is a tiny share of the 1.57 million conventional irrigation pumps operating in the country. This study aims to investigate the economic feasibility of the SIPs operating in the northern region of Bangladesh in terms of estimating financial feasibility and environmental benefits. The study is mainly based on primary data collected from the users of SIPs from two Upazilas of Dinajpur and Rangpur districts. A total of 14 SIPs, categorized into large, medium, and small pumps, are selected randomly from the available SIPs in the study areas. The financial analysis reveals that small SIPs are the most profitable option (20% IRR) for investment. Large SIPs are moderately profitable (10% IRR), and their profitability can be improved (10.50% IRR) by introducing additional uses of solar energy. However, medium SIPs are the worst (5% IRR) option for investment. In the study areas, large and medium SIPs are designed for the 'fees for service model', and small SIPs are designed for the 'fees for ownership model'. It is found that the 'fees for ownership model' is more profitable than the 'fees for service model'. Moreover, the net environmental benefit for all SIPs is found almost equal to the given subsidy for installing them. Also, the net environmental benefit per kilowatt peak (kWp) is highest for the small SIPs. This paper recommends that additional use (e.g., husking, grinding, supply excess electricity to grid, and so on) of solar energy can improve the profitability of investmenton SIPs. Further, the government should continue giving grants for installing SIPs and promote 'fees for ownership model' (small SIPs) for personal use. It would speed up the dissemination rate of SIPs and help increase the country's agricultural production and improve the environmental conditions.

Symmetric lateral inlet pumping stations are commonly utilized for water lifting in agricultural multi-crop irrigation districts, but they often share non-ideal flow patterns, which can easily cause pump vibration and sediment deposition. In this paper, a symmetrical lateral pumping station in an irrigation district is taken as the research object, and CFD (Computational Fluid Dynamics) technology is used to study it. The model test used a model scale ratio of λL = 1:18. Results: By comparing the CFD data and test data, the average relative error for the left station is found to be 3.213%, while that for the right station is 5.107%, indicating that the numerical simulation method is reliable. Six different rectification measures are proposed, the cross sectional flow pattern of the pumping station is observed, and the longitudinal profile of axial velocity distribution in the sump is analyzed. The velocity-weighted average angle and hydraulic loss of each case study are also analyzed. The flow operates smoothly in case study 7. The vortex in the approach channel disappears when the columns and bottom sill are finally installed. Compared to the original case study, the velocity-weighted average angle at the 5# station in case study 7 increased by 14%, and it increased by 13.9% at station #9. The flow became more stable, and hydraulic losses were minimized. The simulated hydraulic loss in case study 7 decreased by 14.2%. These findings can serve as a reference for similar pump station projects.