Search Results (243)

This study analyses household energy consumption patterns and the main energy-related challenges in the rural communities of San Sebastián de Yuluc and Sumaypamba, Ecuador, within the framework of sustainable community energy planning. A quantitative descriptive approach was adopted, based on structured household surveys and statistical analyses using descriptive statistics, nonparametric correlations, and mean comparisons. The results show that electricity consumption in both communities remains below the national household average, while liquefied petroleum gas remains the dominant cooking energy source. Firewood is still used by a portion of households, whereas the adoption of active solar energy systems is practically non-existent. Significant differences in electricity consumption were identified across communities, as were heterogeneous consumption patterns associated with household equipment and living conditions. In Sumaypamba, a strong positive correlation was found between electricity and gas consumption, suggesting complementary rather than substitutive energy use. The findings reveal limited infrastructure, unequal access to modern energy technologies, and a persistent dependence on non-renewable fuels. These results provide evidence to inform local energy transition strategies focused on rural electrification, energy efficiency, and renewable microgeneration to improve energy access, sustainability, and community resilience. Full article

Whereas agroforestry has emerged as a vital Nature-Based Solution (NBS) in the face of climate change, it is yet to be fully embraced in many parts of the world including Uganda. Therefore, understanding the various dynamics surrounding agroforestry adaptation such as the associated benefits and drivers is equally important. The study aimed to explore perceptions and preferences for agroforestry benefits from both ecological and socioeconomic aspects in Uganda. The study employed a non-probability convenience online survey and a total of n = 1138 responses were collected and subjected to descriptive and binary regression analysis. Assessment of agroforestry benefits demonstrated very high ecological preferences. The socioeconomic factors of wood fuel, forest incomes, and forest food and fruits ranked moderately. The models showed a consistent cluster of positive relations among provisioning/protection outlooks of forest food and fruits, water protection and soil conservation services. Moreover, the trade-offs between livelihood dependency for wood fuel/firewood energy, forest income and conservation attitudes (saving nature) were observed. The demographics characteristics (age and gender) were mainly not significant across most models. The efforts of the government of Uganda had a positive and very significant correlation with a preference for wood fuel, indicating policy problems. The study outcomes not only provide a strong case for future studies regarding agroforestry benefits but also offer insights for policy advice such as integrated approaches in agroforestry systems in Uganda. Full article

Residential heater replacement programs in Chile have been evaluated primarily through fine particulate matter (PM) reduction metrics, without considering chemical speciation of the organic aerosols. This screening-level study characterized and compared particle-bound polycyclic aromatic hydrocarbon (PAH) and nitro-PAH emission factors from a residential firewood and a wood pellet heater, under controlled combustion conditions, and assessed their potential toxic equivalency (BaP-TEQ). Compound quantification used 1-nitropyrene as an index calibration compound; all results are semi-quantitative estimates with a combined analytical uncertainty of approximately 13–32%. Firewood combustion yielded a PAH-dominated emission profile with a total BaP-TEQ EF of 187.8 ng/kg, driven primarily by benzo[a]pyrene (BaP; individual contribution: 183.9 ng/kg). Wood pellet combustion showed a nitro-PAH-dominated profile under the applied semi-quantitative analytical conditions, with concentrations expressed as 1-nitropyrene-equivalent estimates and several compounds identified tentatively by NIST library matching, yielding a total screening-level BaP-TEQ EF of 972.1 ng/kg, approximately five-fold higher than firewood under the applied TEF framework and driven primarily by 6-nitrochrysene (toxic equivalency factor, TEF = 10). This screening-level estimate should not be interpreted as a direct human health risk between the two heating systems. Mean PM emission factors were 1.05 ± 0.55 g/kg for firewood combustion and 0.69 ± 0.15 g/kg for pellet combustion (approximately 1.5-fold difference). These results are reported descriptively given the screening-level nature of the analysis. The shift in particulate chemical profile from PAH-dominated in the firewood system to nitro-PAH-dominated in the pellet system suggests that wood pellets from pine may not be a sustainable approach to address air quality problems in Chile, since reductions in PM emissions alone may not capture relevant differences in the organic toxicological profile between these combustion systems. These findings provide a regional baseline for the chemical speciation of residential biomass emissions in Chile. Full article

Sustainable management of the invasive tree Hovenia dulcis (H. dulcis) in the Mixed Ombrophilous Forest (MOF) is crucial for reconciling biodiversity conservation with income generation for smallholders. This study developed a species-specific predictive growth model for H. dulcis and simulated management scenarios across three properties with contrasting invasion intensities. By integrating stem quality, phytosanitary status, and individual growth rates into tree selection criteria, we evaluated trade-offs between timber yield and structural recovery under Continuous Cover Forestry (CCF) principles. The mixed-effects growth model demonstrated high predictive performance (marginal R² = 0.89, RMSE = 2.05 cm), confirming H1 and validating its application as a decision-support tool for long-term silvicultural planning. Results confirmed H2: no single standardized management approach proved appropriate across all sites, as invasion intensity, stand density, and diameter distribution varied substantially among properties and directly determined the most suitable harvesting strategy. In highly invaded stands (Property I), intensive harvesting of 61 trees yielded the highest commercial volume (Vc = 21.84 m³), while in more preserved forests (Property II), conservative selection of 26 trees (Vc = 9.53 m³) prioritized structural quality. Structural recovery periods ranged from 1 to 7 years depending on harvesting intensity, with removal of stagnant large-diameter trees reducing passage time for remaining individuals. Targeting sawlog-quality trees (dbh > 25 cm) was 3.35 times more profitable than firewood production, providing a significant economic incentive for smallholders. These findings demonstrate that property-specific H. dulcis management can transform a biological threat into a productive resource, fostering MOF restoration through active and sustainable use. Full article

Malawi faces increasing pressure on forest resources as rising urban demand for charcoal and firewood accelerates forest degradation in the Lilongwe River Upper Catchment, the primary water source for Lilongwe City. With over 90% of Malawians dependent on biomass energy and the country losing an estimated 33,000 hectares of forest annually, the consequences for water security, soil integrity, and rural livelihoods are severe. Existing research has largely examined woodfuel governance as a social and institutional issue, emphasising policy failures, corruption, and weak enforcement, with limited attention to the biophysical processes through which governance decisions shape landscapes. In this context, tracking changes in soils, water flows, and vegetation dynamics offers an important complementary perspective critical for integrated interventions. This paper proposes a conceptual framework, a Critical Zone Science and Social–Ecological Systems (CZS-SES) framework, which allows examination of how governance systems interact with biophysical processes across scales. The framework, informed by synthesis of policy documents and the empirical literature, highlights the need for more integrated, multidisciplinary approaches to understanding woodfuel governance and its implications for habitability in Malawi and across Africa. Full article

Rural electrification in Sub-Saharan Africa faces a trilemma: cutting carbon emissions, making it economically viable, and achieving fair access to energy for all. This paper develops a multi-objective framework that optimises carbon revenue, net present value (NPV), total energy supply, cooking fuel (firewood and LPG), health costs, and benefit to society. The model uses continuous decision variables: daily energy allocation among four sources (solar, generator, firewood, LPG) to three population groups (men, women, children). The case study is a rural community of 7000 people in Nigeria (Tier 1 energy consumers). Six policy scenarios are considered: baseline, high carbon price, low carbon price, microfinance, government subsidy and community cooperative. This study compared algorithms and identified a hybrid Non-dominated Sorting Genetic Algorithm and Particle Swarm Optimisation II as the most suitable algorithm for solving the formulated optimisation problem. It was found that NPV and unit cost of energy would increase to $175,500 and 26.4 ¢/kWh, respectively, by increasing the price of carbon from $8/ton to $12/ton. Firewood generates health savings and carbon revenue in the range of $4100–$12,270/year. Prices below $8/ton do not induce optimal reconfigurations in the system. The best energy supply (2825 kWh/day) and the lowest unsatisfied demand occur in the government subsidy scenario with the greatest disparity index, displaying an equity-efficiency trade-off. The framework shows that sustainable access to energy can be unlocked using strategic integration of carbon finance, valuation of health benefits and equity constraints. Full article

Across the Global South, energy inequity disproportionately affects women in off-grid communities. However, existing optimisation models for rural electrification rarely incorporate explicit gender constraints. This study develops and validates a multi-objective optimisation framework for balancing environmental sustainability, economic viability, and gender equity in energy access. The model’s objective functions are environmental impact, unsatisfied energy demand, total system cost, and gender inequality. Optimal values for these objectives were generated based on allocation of energy across solar PV, generators, and firewood sources. The Non-dominated Sorting Genetic Algorithm II (NSGA II), particle swarm optimisation (PSO), and a hybrid NSGA-PSO II approach were used to solve the developed model. A remote Nigerian community (Olooji) with 600 households and a population of 7000, classified as Tier 1 energy consumers, was used as a case study. The hybrid NSGA-PSO II method demonstrated superior performance. It achieved the lowest fitness value (4,461,024) by combining the exploration capabilities of NSGA II with the Pareto-optimal convergence strengths of PSO. Over the 25-year planning horizon, the model projects solar energy share to increase from 19.05% to 47.79%, firewood to decrease from 61.90% to 35.45%, and generator share to increase from 14.3% to 14.7%. The community’s energy demand coverage improves from 95.24% to 97.92%. The community maintains a stable male-to-female energy consumption ratio of approximately 1.18:1, while the energy equity gap decreases from 0.2000 to 0.0800 kWh/person/quarter over the planning period. Results demonstrate that the hybrid NSGA-PSO II effectively manages the complexity of multi-objective energy distribution while promoting energy equity and environmental sustainability in rural electrification. Full article

The black carbon (BC) emission resulting from human activity comes mainly from fossil fuels and solid biomass burning, as well as transport fuels due to incomplete combustion. The biggest sources of BC pollution are currently diesel transport and domestic heating appliances burning solid fossil fuels or biomass. Firewood and pellet fuels were used for this BC research. The study used four domestic heating appliances using wood and agricultural waste pellets, as well as several types of firewood. The tests used a gravimetric particulate analysis method to determine the total amount of particulate matter. In further physical and chemical analyses, the emissions are broken down into components, i.e., substances of known composition that can be separated from the sample and weighed. In our study, the BC emissions varied from 0 to 120 mg/MJ depending on the type of boiler (automatic or manual), the combustion mode (based on oxygen supply), and the type of fuel. Emissions varied from 0–8 mg/MJ in a modern pellet-fired and automatically-controlled boiler, and from 1–25 mg/MJ in a wood-fired water heating boiler, with the highest emissions found for softwood (spruce). In the pellet stove with automatic feeding and control, BC emissions varied between 1 and 120 mg/MJ, with the highest emissions detected for wood pellets, and in the wood-burning fireplace, the emissions varied between 6 and 80 mg/MJ, with the highest emissions detected for birch firewood. Full article

Rapid urbanization and population growth in West Africa are intensifying pressure on natural resources and reconfiguring telecoupled supply chains, especially for essential household fuels like charcoal and firewood, here collectively referred to as woodfuel, that link urban consumers to distant production landscapes. However, these cross-regional linkages remain poorly understood. This study, therefore, investigates how urban dynamics structure telecoupled woodfuel flows in Benin, based on quantitative and qualitative surveys of roadside charcoal and firewood traders along the country’s major long-distance roads RNIE#2 and RNIE#3. Collected data included sources, destinations, quantities, pricing, and organizational aspects, combined into a system analysis of fuelwood trading across sending, receiving, and corridor (spillover) areas. Results show consumers growing reliance on charcoal, which in our study amounted to 35,770 t year⁻¹ (97% of the total surveyed flow) to urban areas. Roadside trading depends heavily on connectivity, traffic, and regional trade links, with RNIE#2 emerging as the main corridor, channeling 30,960 t year⁻¹ (84% of the total surveyed flow). Contrary to assumptions that woodfuel sources reflect vegetation density, distances to reported sources were short, with supply shadows averaging 11.3 km (SD = 14.5). Urban demand shapes woodfuel flows by concentrating most trade in major cities—especially the Cotonou–Porto-Novo area, which received 83% (28,770 t year⁻¹) of charcoal and 84% (850 t year⁻¹) of firewood traded along the surveyed flow axes of Benin, with market reach distances varying between 1 and 390 km. Full article

This study examines the determinants and impacts of household biogas adoption among dairy-based mixed crop–livestock systems in West Java, Indonesia. Using primary survey data from 201 households, we estimate adoption drivers through logistic regression and assess post-adoption outcomes using propensity score matching combined with doubly robust estimation. The results show that adoption is primarily driven by structural feasibility and institutional exposure, particularly livestock ownership, participation in technical training, perceived time-saving benefits, and fuel-cost pressure, while general socioeconomic variables such as income and education are not statistically significant. Treatment-effect estimates indicate that adoption leads to significant reductions in LPG and firewood consumption, as well as decreased use of chemical fertilizers, reflecting partial substitution of external inputs with locally available resources. However, these benefits are unevenly distributed, with stronger effects observed among households with larger livestock holdings, while training plays a more critical role for smaller-scale farmers. The findings are interpreted through a sustainability–resilience framework, which is used as an analytical lens rather than a causal measurement model. The results highlight the importance of institutional support, service provision, and policy alignment in determining the durability and scalability of biogas adoption. The study contributes to the literature by integrating determinants of adoption with causal impact estimation and situating household-level outcomes within broader socio-technical systems. Full article

The valorization of agro-industrial residues for solid biofuel production represents a sustainable strategy to meet energy demand, reduce open-field burning, and mitigate environmental impacts. This study aimed to assess the feasibility of producing high-quality briquettes from agro-industrial residues such as oregano stems, pecan shells, and peanut shells sourced from a semi-arid region of northern Mexico. Raw materials were obtained from local industries, processed, and characterized through proximate analysis and determination of higher heating value (HHV). Briquettes were manufactured under various compaction pressures and temperatures without the use of binders, and their physical and energy properties were evaluated according to international standards. Results indicated that all briquette types met Class A quality standards, with moisture contents between 6 and 9%, ash contents below 6%, and HHVs ranging from 18.9 to 21.0 MJ kg⁻¹. Pecan shell briquettes exhibited the highest particle density (1.18 g cm⁻³), while peanut shell briquettes demonstrated superior mechanical performance and the highest Impact Resistance Index (97% and 200, respectively). Oregano stem briquettes showed lower densities but maintained satisfactory energy properties (19.5 MJ kg⁻¹). Beyond its energy potential, this valorization approach contributes to local economic development, reduces environmental pollution, and decreases dependence on firewood in rural communities. Full article

The selection of variables that can be used to predict another variable is usually a challenge, considering that national and international databases contain a considerable amount of information and that the literature, in some circumstances, is unclear about the most adjusted predictors and the most accurate models. Without appropriate approaches to select the variables, there are actual risks of considering irrelevant information and ignoring important data in the prediction analysis. Artificial intelligence and, in particular, machine learning methodologies provide interesting support for identifying the most important predictors and the most accurate algorithms. In this way, this research intends to identify the most important variables to predict bioenergy production and consumption and select the most accurate models. For this, statistical information from the FAOSTAT database for the year 2023 was considered. This information was analysed considering machine learning approaches following IBM SPSS Modeler (Version 18.4) procedures. The results obtained indicate that 50% of bioenergy is produced and consumed worldwide by five countries (India, China, the United States of America, Brazil and Ethiopia) and most of this energy comes from firewood (60%). Out of a total of 456 inputs (consideration of this set of FAOSTAT variables is a novelty in the literature), bioenergy production and consumption are mainly explained by fuelwood production, with elasticities of 0.75% and 0.7%, respectively. The explanatory variable “fuelwood production” was identified from the most significant variables found by the machine learning approaches and was subsequently used as an independent variable in linear regressions. XGBoost Linear, XGBoost Tree, Linear, CHAID, Tree-AS, and C&R Tree are the most accurate models (lower relative error) for predicting bioenergy production and consumption worldwide. Full article

Moving toward sustainable energy in small-scale dairies is an indispensable requirement and a significant challenge in developing countries. This study investigates a solar-powered refrigeration system with heat recovery designed to address the energy challenges faced by small-scale dairy farmers in off-grid areas of developing nations. It presents a novel solar-powered refrigeration system with integrated heat recovery, experimentally optimized to simultaneously deliver heating and cooling while valorizing waste heat and synergistically integrating solar energy to establish a decentralized and energy-autonomous milk preservation system for off-grid applications. The proposed system successfully recovers an average of 55% of the heat rejected by the condenser, thereby delivering more than 1000 W of usable thermal energy necessary for milk pasteurization. The experimental findings showed a coefficient of performance of 4.7, representing a 43% improvement over conventional systems, and achieved a Carnot efficiency of 42%. In addition, the system yields an annual energy savings of 3650 kWh and reduces carbon emissions by 971 kg per year for a 50 L unit. These findings underscore the system’s substantial potential to enhance energy efficiency, promote sustainability, reduce spoilage, improve incomes, mitigate carbon emissions, and enhance local milk preservation capabilities within small-scale dairy operations, minimizing reliance on diesel or firewood, particularly in regions that are distant from access to grid energy. Full article

This study examines the drivers, practices, and challenges associated with firewood use through a survey of 603 rural households in Hungary. The results reveal that 97% of respondents use firewood exclusively for heating, primarily through mixed-fuel boilers and room heating systems, while advanced technologies such as wood gasification boilers are rare. A significant proportion (71%) of rural households that utilise firewood have access to alternative heating options, with natural gas being the most prevalent. In 27% of households in the survey, despite the availability of alternative heating options, firewood remains the primary heating energy source, while the same share uses it only as a secondary option. The vast majority (95%) of the households that use firewood, but no alternative energy sources are available, do not plan to change to alternative fuels, mostly because of the high costs entailed. It is anticipated that firewood will persist as a stable component of the rural energy landscape. The survey results indicate that household waste combustion is a current practice and remains an option in the future. Educational attainment has been demonstrated to correlate with heating choices, with lower education levels correlating with a greater propensity for the use of firewood. Full article

Biogas production from animal manure has huge potential in mitigating greenhouse gas emissions and replacing the higher environmental footprint energy sources. This study aimed to assess the technical functionality, environmental benefits, and economic advantages of low-cost biodigesters suitable for rural areas, which can produce biogas from animal manure. Four low-cost polyethylene tubular biodigesters with a concrete retaining wall with capacities ranging from 4 to 14 m³ were installed in small dairy production units in Chiapas, Mexico. Four profitability indicators were calculated. The IPCC’s methodology was used to calculate emissions from biogas and firewood burning, and the emission reduction from manure management. These biodigesters generate between 526 and 1993 m³ of biogas year⁻¹ and represent a savings of USD 197–744 year⁻¹ in energy costs. The four profitability indicators were favorable. Moreover, these biodigesters reduce 70–73% of greenhouse gas (GHG) emissions through manure management, that is, between 1.5 and 5.1 t CO₂e year⁻¹, and 1.3–5.1 t CO₂e year⁻¹ from firewood displacement. These findings provide critical insights into the potential of sustainable and low-cost biodigesters that can be implemented effectively in small-scale dairy farms in rural areas in many parts of the world. Full article