Nepal has announced an economy-wide net-zero emissions target by 2045. To achieve this, ambitious energy-related goals were set in the past, yet many targets remain unmet. We developed and validated a bottom-up model for Nepal (BU-NEP) using the Long-range Energy Alternatives Planning System (LEAP), quantifying energy demand, supply and emissions for scenarios from 2021 to 2050 to assess persistence of pathways beyond 2045. This study examined eight future energy scenarios for Nepal which reflected continuation of past development trends and policy sphere aligned with both domestic legislative milestones and international climate change pledges. The cases were identified through an extensive review of 53 policies from 1984 to 2022 and consultations with nine energy experts. Four demand sectors (domestic, industrial, commercial, and transportation), 20 end-uses, 11 major fuel-types and eight supply side technologies were considered in the simulation. The BU-NEP model was calibrated for 2019, validated for 2021 and 2022, and simulated from 2021 to 2050 at annual timesteps, utilizing comprehensive secondary data from multiple national and international sources. The results indicate significant potential for savings in energy consumption (up to 300 Mtoe until 2050) and emissions reduction (from 66.6 MtCO2-e in baseline to 10.5 MtCO2-e by 2050) through integrated demand and supply interventions. Modernizing the household sector by adopting cleaner energy and efficient appliances could potentially reduce energy consumption by 53

This study evaluates the impacts of climate change on flooding and streamflow in Nepal’s Kaligandaki River Basin (KRB) considering the Coupled Model Intercomparison Project Phase-6 (CMIP6) based Shared Socio-Economic Pathway (SSP) scenarios: SSP245 and SSP585. Using a historical baseline (1985–2014) daily hydro-meteorological data, projections for mid-century (2031–2060) and far-century (2061–2090) were derived from top-ranking three General Circulation Models (GCMs) for precipitation and temperature. Results suggest a significant warming trend, with maximum and minimum temperatures projected to rise by up to 3.8 °C and 3.9 °C, respectively, under SSP585 by 2090. Monsoon precipitation could increase by up to 17.4

Aminophenol dioxygenases (APDO) are mononuclear nonheme iron enzymes that utilize dioxygen (O2) to catalyze the conversion of o-aminophenols to 2-picolinic acid derivatives in metabolic pathways. This study describes the synthesis and O2 reactivity of two synthetic models of substrate -bound APDO: [FeII(TpMe2) (tBu2APH)] (1) and [FeII(TpMe2)(tBuAPH)] (2), where TpMe2 = hydrotris(3,5-dimethylpyrazole-1-yl)borate, tBu2APH = 4,6-di-tert-butyl-2-aminophenolate, and tBuAPH2 = 4-tert-butyl-2-aminophenolate. Both Fe(II) complexes behave as functional APDO mimics, as exposure to O2 results in oxidative C-C bond cleavage of the o- aminophenolate ligand. The ring -cleaved products undergo spontaneous cyclization to give substituted 2-picolinic acids, as verified by 1H NMR spectroscopy, mass spectrometry, and X-ray crystallography. Reaction of the APDO models with O2 at low temperature reveals multiple intermediates, which were probed with UV-vis absorption, electron paramagnetic resonance (EPR), Mossbauer (MB), and resonance Raman (rRaman) spectroscopies. The most stable intermediate at -70 degrees C in THF exhibits multiple isotopically -sensitive features in rRaman samples prepared with 16O2 and 18O2, confirming incorporation of O2 -derived atom(s) into its molecular structure. Insights into the geometric structures, electronic properties, and spectroscopic features of the observed intermediates were obtained from density functional theory (DFT) calculations. Although functional APDO models have been previously reported, this is the first time that an oxygenated ligand-based radical has been detected and spectroscopically characterized in the ring -cleaving mechanism of a relevant synthetic system.

Biological and synthetic catalysts often utilize iron in high oxidation states (+IV and greater) to perform challenging molecular transformations. A coordination complex featuring an Fe(VII) ion has now been synthesized through sequential oxidations of nonheme iron-nitrido precursors.

This study examines the characteristics (magnitudes, trends, and frequency of occurrences) of extreme floods in Nepal, a country that is at significant risk from floods. Daily discharge data from 1980 to 2015 of three gauging stations (Chisapani of Karnali Basin, Devghat of Narayani Basin, and Chatara of Koshi Basin) were used to assess the largest 1 % of flows, the annual top five high flows, and floods of different return periods (2-, 5-, 10-, 20-, and 100-year). In addition, temporal trend analysis of the flood peaks was carried out using the Mann–Kendall test and Sen's slope estimates. Results show that the magnitudes of the largest 1 % flows range from 6310 to 17 900, from 6967 to 12 100, and from 6080 to 9610 m3 s−1 at Chisapani, Devghat, and Chatara, respectively. The monsoon, especially from mid-June to early September, consistently witnesses over 90 % of 1 % extreme flows, with August registering more than 51 % of these occurrences. July and August combine for 81 % of the top five flow events, predominantly in August. Despite insignificant flow changes at a 95 % confidence level, extreme floods (2-, 5-, 10-, 20-, and 100-year return periods) are concentrated heavily in July and August, with August's second fortnight recording the most flood events. This assessment emphasizes July and August as critical months for extreme floods, aiding Nepalese authorities in planning dynamic resource allocation, disaster response, and effective flood management.

Scholars recommend country (or region) specific energy security indices capable of adequately considering local specificities in the absence of a ‘universal’ index. Such an index is not available for Nepal. Hence, this study is the first to develop the Energy Security Composite Index of Nepal (ESCOIN), applying a comprehensive indicator-based approach to quantify energy security (ES) of Nepal. We build upon the notion that a country is able to trade energy when it is energy secure. We quantify Nepal’s energy security and qualitatively assess the prospect for regional power trade in South Asia. A long list of 77 indicators is compiled from an extensive review of international literature. Based on the context, applicability to Nepal, data availability and conditions of multi-collinearity, this list of indicators is narrowed down to 21. Principal Component Analysis is then applied to evaluate the importance of the components for ESCOIN. Our results show that Nepal has consistently held a boundary position between “moderate” to “high” classes of ES in the last decade. We identify key reasons for this. First, the country’s domestic sector is over-reliant on traditional fuels (dry-dung, firewood and agricultural residues). Second, Nepal faces a problem of suppressed demand in the absence of energy-intensive development activities in all productive sectors of the economy. Third, the growth in the energy demand is met only marginally by domestic hydropower and other renewables, and largely by increasing imports. Hence, we surmise a ‘pseudo energy secure’ state for Nepal. Although efforts are underway, electricity trade with China, Bangladesh and other South Asian Association for Regional Cooperation (SAARC) countries is economically difficult and technically challenging. Hence, cross-border electricity trading, particularly with India, can be seen as an opportunity for Nepal provided considerable infrastructural development occurs, institutional capacity is strengthened, and genuine political commitment and trust are sustained. Moreover, Nepal should focus on achieving self-sufficiency in energy through domestic hydropower and renewable sources and aim to stabilize energy consumption rather than being overly ambitious of exports, at least in the near future.

Our study investigates the relatively unexplored relationships between socio-economic factors and perceptions of climate change and their influence on household energy preferences in developing contexts, taking the case of Nepal. We aim to achieve two objectives: to create a robust model identifying key socio-economic and climate perception variables affecting household energy behaviour; and to compare the respective impacts of these factors. Applying a mixed-method approach, we surveyed 323 households across 49 districts and three physiographic regions (high hills, mid hills and Terai plains) of Nepal. We fixed the explanatory and response variables through literature review and evaluated three ordinal logistic regression models: one focused solely on socio-economic factors, the second only on climate perception and the third a composite model integrating both. Data statistics showed that 47 % of the respondents preferred no change to their existing energy status, 23 % opted to rely completely on grid-electricity, 14 % favoured switching to renewables, while 16 % preferred an optimal combination of grid-electricity and renewables for their household use. The Composite-model was found to be the best fit model for our dataset. The identified key socio-economic factors include urbanization, education levels, and the availability of energy alternatives indicating a wide disparity in the energy access and use across the different socio-economic categories of Nepal. Likewise, magnitude and timing of summer and winter rainfall, changes in the household energy demands and community level subsidies were found to be the significant climate change perception variables. Hence, our findings highlight the need for better access to modern energy and financial incentives, mostly to the rural remote areas, and community-awareness initiatives throughout the country supported by comprehensive energy policies for sustainable renewable energy transition at the household level as well as in mitigation of the impacts of climate change. By enhancing this policy-science-society interface, our research contributes valuable insights for developing effective strategies to promote renewable energy adoption in similar developing contexts.

We modelled the hydrological response of a central Himalayan country Nepal in HEC-HMS hydrological model, disaggregating the country into three large basins (Eastern, Central and Western) and 94 sub-basins, using daily precipitation and temperature data from 176 and 106 observation stations, respectively. The models were calibrated and validated at 24 stream flow gauging stations over a 20-years period (1991–2010) and simulated for a baseline (1981–2015) and future 35 years. Six future climate scenarios were generated through a bottom-up weather generator using the Autoregressive Moving Average Method (ARMA) method which were analyzed using the hydrological models. We compared the likely impacts of changed climate in future on energy generation of 30 large run-of-river hydropower projects with respect to the Baseline. This is the first study in Nepal which has used the bottom-up method of climate change analysis at the national scale focusing on hydropower. Results indicate regional differences in hydrological responses; the Eastern Basin hydropower projects are expected to face larger variabilities in energy generation compared to the Central and Western Basin projects. However, many projects in the Central and Western basins are likely to meet only 70

Abstract Accurate estimation of design floods is necessary for developing effective flood‐management strategies. Climate change (CC) studies on floods generally consider alterations in mean runoff using ensembles compared to a base period. In this study, we examined the plausibility and implications of applying individual climate model‐generated flows versus their ensembles to estimate peak floods (magnitude and timing of occurrence), using Budhigandaki River Basin of Nepal as a case study. Annual maximum one‐day floods were derived for four future climate scenario projections (cold‐dry, cold‐wet, warm‐wet, and warm‐dry) from simulated daily flow series. Future floods of six return periods estimated for the individual climate scenarios were compared with their “Ensemble” (combiner for the ensemble series is the arithmetic mean of daily floods), “Average,” and ‘Baseline.” Results showed that magnitudes of the flood peaks are such that those estimated using “Ensemble” < “Average” < individual series. We conclude that ensemble series should not be used for flood estimation because of the averaging effect. Designers should consider at the least the “Average” instead of the “Ensemble” series while designing climate‐resilient flood structures. Furthermore, the occurrences of flood peaks are likely to be confined within the monsoon season for the “Ensemble” but spread out in the other months for the individual climate scenarios. This could have direct implications on the availability and mobilization of resources as well as the need for a year‐round operational early warning system for flood risk management.

In this study, we assessed the accomplishments and shortcomings of an exhaustive collection of energy policies of Nepal over four decades, using a five-dimensional energy security framework (availability, affordability, technology, sustainability and governance) for sustainable development. We adopted a mixed-method approach involving thorough review of 70 policy documents (1984-2022), systematic review of 86 peer-reviewed journal articles on Nepal's energy policy, and consultations with 11 experts. Our evaluation shows that while there is a progressive trend, Nepal's energy policies face challenges of political instability, governance issues, siloed development practices, lagging research and development, inefficient energy demand management, and heavy reliance on international support. Additionally, we offer four tailored recommendations for the related stakeholders: supply-side management, demand-side management, multi-sector collaboration, and political stability and good governance. The insights and recommendations we provide have significant regional implications, particularly in the context of potential cross-border clean electricity sharing in South Asia.

Study region: The study region is 23 different watersheds across Nepal.Study focus: This study aims at assessing the strengths and weaknesses of widely used regionalization methods for simulating daily hydrograph and flow duration curve in a comparatively large sample of 23 medium to small-sized watersheds across Nepal. We employed a deductive approach based on extractable watershed properties to test the performance of four regionalization methods: principal component regression (PCR), random forests (RF) under regression-based methods, spatial proximity (SP), and physical similarity (PS) under donor-based methods in a New hydrological insights for the region: The GR4J rainfall-runoff model coupled with Cemaneige snow module (GR4J-CN) could provide good simulation for majority of the watersheds with median NSE of 0.76 and 0.74 for calibration and validation periods respectively. Model simulation using parameter values predicted from different regionalization methods showed satisfactory results in majority of the watersheds for daily hydrograph simulation. While there wasn't a single method that performed well in all of the watersheds, the physical similarity methods was found to be the most robust. Visual comparison of errors in flow duration curve (FDC) also indicated physical similarity method as a better approach in ungauged watersheds of Nepal. Further experiment using multiple donors using the output averaging option was found to increase the performance of donor-based methods while the parameter averaging option resulted in a drop in performance. The study provides a comprehensive assessment of regionalization methods and advocates the use of hydrological model regionalization as a promising tool for streamflow prediction in ungauged Himalayan watersheds.

Research on social aspects of energy and those applying machine learning (ML) is limited compared to the 'hard' disciplines such as science and engineering. We aim to contribute to this niche through this multidisciplinary study integrating energy, social science and ML. Specifically, we aim: (i) to compare the applicability of different ML models in household (HH) energy; and (ii) to explain people's perception of HH energy using the most appropriate model. We carried out cross-sectional survey of 323 HHs in a developing country (Nepal) and extracted 14 predictor variables and one response variable. We tested the performance of seven ML models: K -Nearest Neighbors (KNN), Multi-Layer Perceptron (MLP), Extra Trees Classifier (ETC), Random Forest (RF), Ridge Classifier (RC), Multinomial Regression-Logit (MR-L) and Probit (MR-P) in classifying people's responses. The models were evaluated against six metrics (confusion matrix, precision, f1 score, recall, balanced accuracy and overall accuracy). In this study, ETC outperformed all other models demonstrating a balanced accuracy of 0.79, 0.95 and 0.68 respectively for the Agree, Neutral and Disagree response categories. Results showed that, compared to conventional statistical models, data driven ML models are better in classifying people's perceptions. It was seen that the majority of the surveyed people from rural (68%) and semi-urban areas (67%) tend to resist energy changes due to economic constraints and lack of awareness. Interestingly, most (73%) of the urban residents are open to changes, but still resort to fuel-stacking because of distrust in the state. These grass-root level responses have strong policy implications.

Every energy generation technology, including hydropower, has its own strengths and shortcomings. We carried out vulnerability assessment (VA) applying a bottom-up multi-disciplinary indicator-based method considering people's perception of five dimensions of a storage type (ST) "national pride" hydropower project-1200 MW Budhi Gandaki Hydropower Project (BGHP) in Nepal. We also examined how ST projects can contribute to sustainable development goals (SDGs) overcoming the vulnerabilities. Primary data on people's perception were collected through focus group discussions and 200 household questionnaire surveys conducted within the most vulnerable areas. People perceived the "Physical" dimension as the most impactful. The local community is optimistic about some infrastructure development, but issues related to compensation, resettlement and physical stressors were found to be very sensitive for the effective implementation of the project. Expectations of the local people and proposed plans by the government are concurrent in some issues but not in all. Our analysis shows that the BGHP has the potential to be multi-dimensionally beneficial (to eight SDGs) for Nepal, provided that supportive policies are formulated and implemented stringently. Extending the project as multi-purpose, pumped storage and other improvements such as floatovoltaics are some of the plausible recommendations for harnessing maximum benefits from this important project while minimizing threats. Moreover, the methodological framework can be conveniently replicated for conducting VA of hydropower projects under comparable physical and socio-economic conditions.

Donor-driven research and implementations in renewable energy (RE) might not necessarily resonate with the physical, social, economic and political settings of the developing world. We take a developing South Asian country – Nepal – to examine why solar and wind technologies have failed despite tremendous donor-support and subsidies during the last three decades. We combine extensive literature review, expert interviews and own readings from our two decades-long professional career in the RE sector of Nepal to arrive at rational conclusions. Almost all past internationally funded and government-subsidized off-grid solar and wind energy projects failed upon discontinuation of funds. Furthermore, the pristine Himalayan environment was forced to bear the burden of hazardous waste management. Nepal, being one of the best countries for hydropower, should concentrate on this technology. The suitability, convenient availability of other feasible alternatives and social acceptance decides the fate of technologies. Donations/subsidies need to be better utilized by developing a bottom-up “ecosystem” fostering new technologies to be a part of the energy mix sustainably. Through this paper, we provide specific recommendations for the use of donations and subsidies in the RE sector which have been drawn from the Nepal case but are applicable to the Global South in general.

Better irrigation facilities leading to “more crop per drop” are today’s needs. This study examines how the overall water balance of Sunkoshi, Marin, and Bagmati Basins will be altered by implementing the Sunkoshi-Marin Diversion Project (SMDP) to fulfill the unmet demands of the Bagmati Irrigation Project (BIP) in the Bagmati Basin via the Marin Basin in Nepal. The specific objectives are to: i) quantify “too much” and “too little” water peculiar to the study basin based on historical data; ii) evaluate water availability, irrigation water requirement, and deficits with and without SMDP; and iii) provide evidence-based recommendations on the effectiveness of the SMDP considering hydropower generation, irrigation and low- and high-flow conditions. Thirty years of historical daily flow data (two gauging stations) and precipitation data (15 stations) were obtained from the Department of Hydrology and Meteorology. Other spatial input data were acquired from relevant authorized sources. Water availability has been estimated using flow at the diversion sites while the irrigation requirements have been calculated based on secondary information. Results show that additional water is not at all required for Marin and Bagmati Basins in the monsoon season. Rather, the diverted water increases the flood hazard. Moreover, the contribution of hydropower from SMDP to the national energy demand is insignificant in the monsoon. However, the SMDP was found to play an important role in meeting the irrigation deficits during the dry season. Its contribution to hydropower production in the lean period is also commendable. However, the proposed irrigation requirement of the BIP cannot be met even after the implementation of the SMDP. More importantly, there is a high probability of the intended diversion flow not being available in the Sunkoshi River (donor) which could have severe consequences downstream. Therefore, additional options for conjunctive use need to be explored.

The observation of single-molecule magnetism in transition-metal complexes relies on the phenomenon of zero-field splitting (ZFS), which arises from the interplay of spin-orbit coupling (SOC) with ligand-field-induced symmetry lowering. Previous studies have demonstrated that the magnitude of ZFS in complexes with 3d metal ions is sometimes enhanced through coordination with heavy halide ligands (Br and I) that possess large free-atom SOC constants. In this study, we systematically probe this "heavy-atom effect" in high-spin cobalt(II)-halide complexes supported by substituted hydrotris(pyrazol-1-yl)borate ligands (TptBu,Me and TpPh,Me). Two series of complexes were prepared: [CoIIX(TptBu,Me)] (1-X; X = F, Cl, Br, and I) and [CoIIX(TpPh,Me)(HpzPh,Me)] (2-X; X = Cl, Br, and I), where HpzPh,Me is a monodentate pyrazole ligand. Examination with dc magnetometry, high-frequency and -field electron paramagnetic resonance, and far-infrared magnetic spectroscopy yielded axial (D) and rhombic (E) ZFS parameters for each complex. With the exception of 1-F, complexes in the four-coordinate 1-X series exhibit positive D-values between 10 and 13 cm-1, with no dependence on halide size. The five-coordinate 2-X series exhibit large and negative D-values between -60 and -90 cm-1. Interpretation of the magnetic parameters with the aid of ligand-field theory and ab initio calculations elucidated the roles of molecular geometry, ligand-field effects, and metal-ligand covalency in controlling the magnitude of ZFS in cobalt-halide complexes.

Despite being one of the proven clean-energy technologies, hydroelectricity is losing attention in global research. Hydroelectricity is extremely important for countries possessing the required water resources, already heavily reliant on it and those lacking the financial capacity to invest in other expensive energy technologies. This study assessed the possible impact of climate change (CC) on hydro-energy generation in the Nepalese Himalaya (possessing eight peaks out of 14 over 8000 m) with a tremendous hydropower potential (similar to 50,000 MW). A planned 1200 MW storage type Budhigandaki Hydroelectricity Project is taken as a case. We estimated the energy generation for the baseline as well as 10 CC scenarios considering RCPs 4.5 and 8.5 at monthly, seasonal, and annual temporal scales for the mid-century. Results show that energy generation is highly dependent on the reservoir operating rule. The average annual energy generation is expected to vary within -5 to +12% of the base case in the mid-century, with significant variations across the months. We also infer that designing hydroprojects based on ensembled climate values could lead to a "rosy" but less probable and risky picture of energy generation in the future. Therefore, assessment of a wide spectrum of plausible CC scenarios are recommended. Storage type projects with provision of flexible operating rules considering finer temporal resolution and allocation to competing users (in case of multipurpose projects) supported by appropriate policies are desirable for climate resiliency. Complementing the existing energy generation mix with other technologies in areas where hydroelectricity is expected to undergo adverse impacts of CC is warranted for attaining future energy security and environmental safeguarding. Possibility of additional energy due to CC is a strong motivation for this region to focus on hydroelectricity development in the future.

This study is aimed at evaluating the impacts of climate change (CC) on the water-energy-economics-continuum considering a storage type hydroelectricity project (STP). Inflows from ensembled CC scenarios for two RCPs (4.5 and 8.5) and three time-windows (near-future, mid-future, far-future) until the end of this century, generated from an earlier study by the same team, was used for the analysis. The proposed 1200 MW Budhigandaki Hydropower Project in Nepal is taken as a case. A set of reservoir operating rules were derived considering the baseline data which was then used to generate future energy and revenue at the monthly, seasonal and annual timescales. Results show that future annual energy is expected to increase by about 9–13% from the baseline. Furthermore, future revenue generation is projected to increase in the range of 20–28 million USD annually. This overall gain in the revenue due to additional energy generation is an anticipated positive impact of CC which is capable of contributing to the reduction of greenhouse gases and minimizing fossil-fuel laden trade deficit. This study recommends that: STPs with the provision of flexible operating rules are desirable for climate resiliency in hydroelectricity; areas expected to witness decreased future hydroelectricity generation need to explore other alternative sources of renewable energy; and the policy instruments pertaining to the financial aspects of hydroelectricity should be continuously updated considering future conditions.

This is a pioneer study aimed at quantifying energy security (ES) of Nepal, examining the energy trilemma and analysing its regional energy sharing prospect combinedly. We reviewed 38 articles on ES quantification from across the world to derive 33 indicators encompassing six multidisciplinary dimensions representing the overall energy sector of Nepal. We applied a well-established indicator-based method to develop the Energy Security Composite Index of Nepal (ESCOIN) and examined the evolution of the nation’s energy situation over the last decade. The impact of the indicators on ESCOIN was assessed by principal component analysis (PCA). Results showed that Nepal consistently held a ‘moderate’ status during the analysed period. This can be attributed to excessive reliance on traditional fuels, slow rise in the energy demand due to lack of energy intensive development activities, rate of energy import being almost parallel to the growing demand and some methodological limitations. Furthermore, Nepal ranks very low in the Energy Trilemma Index globally primarily because of its poor ES and equity; its environmental sustainability is comparatively better. We deduce that the possibility of Nepal contributing its hydroelectricity to the energy-hungry neighbours, despite the small generation, is an opportunity but at the stake of large infrastructure development and sincere political commitment and trust. Furthermore, although the values of ESCOIN show a ‘pseudo energy secure’ condition, a lot needs to be attained by Nepal for an energy secure future especially through reduced reliance on traditional and fossil fuels and being self-sufficient, aggressive hydro-electricity development taking the lead.