Off-grid Communities Research Articles

Harvesting the sun twice: Energy, food and water benefits from agrivoltaics in East Africa

Food, energy and water insecurity are concomitant challenges facing many communities in East Africa. Agrivoltaic systems – agriculture integrated with photovoltaic panels – address all three challenges, providing low carbon electricity, food production and water conservation on the same land area. Agrivoltaics have proven benefits for the food-energy-water nexus in the USA, Europe and Asia, but research is lacking in sub-Saharan Africa, where energy access remains low, and climate change and water scarcity threaten food systems. This study presents evidence for concomitant electricity generation, food production and water conservation from agrivoltaic systems in Tanzania and Kenya, demonstrating the viability of these systems for both grid-tied agribusinesses and rural, off-grid communities. Performance of some crops improved under agrivoltaics, generating higher incomes for farmers and agribusinesses while reducing energy bills and/or enhancing energy supply. Crop survivability during a warm period was greater under the agrivoltaic system, indicating potential for climate change resilience. Panel shading reduced irrigation demand, thus some crops achieved greater yields while needing less water input. Rainwater harvesting from panel runoff further reduced irrigation needs. Combining energy infrastructure with agriculture enhanced land productivity for all crops at both sites. Agrivoltaics, whether grid-tied or off-grid, could address multiple Sustainable Development Goals in East Africa simultaneously by contributing to energy security, climate change-resilient food production, and water conservation in the region.

Comprehensive methodology for the integrating of the organic rankine Cycle-ORC with diesel generators in off-grid areas: Application to a Colombian case study

Efficient fuel management in diesel generator sets for power generation in non-grid areas is a persistent concern. In this context, the use of an Organic Rankine Cycle (ORC) to recover heat from exhaust gases from diesel generator sets represents a promising route for additional power generation. To undertake such projects, it is necessary to understand the critical parameters related to diesel engines, including the specific fuel consumption, mass flow, and exhaust gas temperature. These parameters are fundamental to the sizing process of the ORC heat recovery system. This study introduces an innovative methodology for evaluating the operation of diesel-ORC systems based on the load demand of off-grid communities. The proposed system is a viable solution for the generation of additional power with the objective of improving the overall efficiency and meeting higher energy demands in isolated areas. Four organic fluids were selected for the ORC: R245fa, benzene, cyclopentane, and toluene. This selection was made based on many criteria, including global warming potential (GWP), ozone depletion potential (ODP), and safety classification (ASHRAE 34). In addition, the exergy behaviors of these fluids were reviewed. A comparative analysis was subsequently conducted for a non-interconnected region of Colombia to evaluate the performance of a diesel generator operating independently and in conjunction with the diesel ORC system. The key indicators employed were fuel consumption savings (L/year), energy produced (MWh/year), levelized cost of energy (LCOE, USD/kWh), and payback period (years). The results demonstrated that, over the course of a 1-year simulation period, the benzene ORC system exhibited the highest overall energy efficiency, achieving a value of 41.38%. The exergy analysis indicated that toluene had lower irreversibilities, achieving an exergy efficiency of 44.78%, followed by benzene (43.5%. Furthermore, the diesel-ORC system using benzene demonstrated a notable decrease in the specific fuel consumption from 0.282 to 0.247 L/kWh, signifying a 10.52% reduction in the annual CO2eq emissions. The cost of electricity generation decreased by 4.3%, with investment payback periods not exceeding 14 years.

Innovative hybrid energy storage systems with sustainable integration of green hydrogen and energy management solutions for standalone PV microgrids based on reduced fractional gradient descent algorithm

This paper investigates innovative solutions to enhance the performance and lifespan of standalone photovoltaic (PV)-based microgrids, with a particular emphasis on off-grid communities. A major challenge in these systems is the limited lifespan of batteries. To overcome this issue, researchers have created hybrid energy storage systems (HESS) along with advanced power management strategies. This study introduces innovative multi-level HESS approaches and a related energy management strategy designed to alleviate the charge/discharge stress on batteries. Comprehensive Matlab Simulink models of various HESS topologies within standalone PV microgrids are utilized to evaluate system performance under diverse weather conditions and load profiles for rural site. The findings reveal that the proposed HESS significantly extends battery life expectancy compared to existing solutions. Furthermore, the paper presents a novel energy management strategy based on the Reduced Fractional Gradient Descent (RFGD) algorithm optimization, tailored for hybrid systems that include photovoltaic, fuel cell, battery, and supercapacitor components. This strategy aims to minimize hydrogen consumption of Fuel Cells (FCs), thereby supporting the production of green ammonia for local industrial use. The RFGD algorithm is selected for its minimal user-defined parameters and high convergence efficiency. The proposed method is compared with other algorithms, such as the Lyrebird Optimization Algorithm (LOA) and Osprey Optimization Algorithm (OOA). The RFGD algorithm exhibits superior accuracy in optimizing energy management, achieving a 15 % reduction in hydrogen consumption. Its efficiency is evident from the reduced computational time compared to conventional algorithms. Although minor losses in computational resources were observed, they were substantially lower than those associated with traditional optimization techniques. Overall, the RFGD algorithm offers a robust and efficient solution for enhancing the performance of hybrid energy systems.

Assessing the Socio-Economic Impacts of Solar Home Systems on Chingad, Surkhet

This study assesses the multifaceted socio-economic impacts of Solar Home Systems (SHS) on the remote community of Chingad, Surkhet. Employing a comprehensive research framework, we investigate the extent to which the adoption of SHS has influenced the livelihoods, economic activities, and social dynamics within the community. Through a combination of quantitative and qualitative methodologies, we analyzed the economic benefits, social empowerment, and environmental sustainability associated with the integration of solar energy. The limitations of the study included its focus on Chindgad-5, Surkhet. This research employed a descriptive-analytic approach within an exploratory research design. In the study area, a total of 386 households were included, with 188 utilizing solar energy in December 2023 AD from field observation. The research focused on a subset of 36 purposely selected solar home system users. Energy consumption patterns varied among ethnic groups and social classes, and universal electricity access was not observed in the study area. The study integrated both descriptive and exploratory elements to comprehensively address its objectives, utilizing a combination of primary and secondary data. For policymakers, development professionals, and other stakeholders engaged in sustainable energy projects in similar circumstances, the findings offer insightful information about the complex relationships that are present between solar technology and the local socioeconomic fabric. The study provides valuable insights for policymakers, energy planners, and development organizations working towards sustainable and inclusive energy solutions in rural Nepal. The successful integration of SHS not only addresses energy needs but also contributes to economic development and improved living conditions in off-grid communities.

A high-performance all-day vertical thermoelectric generator based on a double-sided reflective structure

Harvesting environmental energy sources is crucial for achieving renewable energy generation and net-zero emissions. However, ensuring uninterrupted electricity generation from environmental energy sources remains challenging. In this study, we present a simple, compact, and expandable all-day vertical passive thermoelectric generator (V-TEG) with a double-sided reflective structure that simultaneously harnesses solar and space cold energy. Outdoor experimental measurements, combined with finite element simulation analysis, revealed that the optimal angles of the solar reflector relative to the TEG range from 30° to 50°. Additionally, the TEG placed in the north–south orientation was found to enhance its daytime performance. The use of low-cost black paint combined with the solar reflector achieved equivalent spectral selectivity, effectively minimizing the infrared heat loss of the hot end of the TEG. During a 48-h outdoor test, the V-TEG achieved an average daytime power of 112.00 mW/m2 and a peak of 363.42 mW/m2. Comparative experiments demonstrated that the V-TEG outperformed horizontally placed TEG during the daytime. Furthermore, scaling the system by connecting three TEGs in series significantly increased the daily power output. This compact V- TEG system offers a promising solution for long-term power generation in low-power sensors and off-grid communities, supporting renewable energy and carbon neutrality goals.

Multi-objective optimization of a solar-biomass multi-generation system with dual-stage desalination for brine minimization

A hybrid solar-biomass multi-generation system feeding an off-grid community is proposed in this study. An organic Rankine Cycle (ORC) generates electricity by harnessing the thermal energy supplied by the hybrid heat generation system. Part of the produced electricity is utilized to meet the community's electricity needs, while another fraction powers a brackish water reverse osmosis unit (RO). The waste heat from the ORC is recovered to produce domestic hot water and to drive a membrane distillation (MD) unit for RO brine minimization. A multi-objective optimization of the proposed system is conducted using the NSGA-II algorithm and TOPSIS decision-making tool considering plant's overall energy efficiency, exergy efficiency, and the total exergoeconomic cost of the useful products as objective functions. The study's results indicate that the overall optimal solution is achieved using R1336mzz(Z), with corresponding energy efficiency, exergy efficiency and hourly exergoeconomic cost of 45.31%, 5.39%, and 87.68 €/h, respectively. Moreover, the unitary costs associated with the useful products are 0.207 €/kWh, 0.029 €/kWh, 0.683 €/m3, and 3.36 €/m3 for the produced electricity, domestic hot water, RO permeate and MD distillate, respectively. In terms of sustainability, the system is not only renewable-driven but also achieves a 21% reduction in brine discharge through heat recovery at the ORC condenser compared to single-stage RO desalination. Additionally, using R1336mzz(Z) with its low global warming potential of 2 significantly lowers CO2 equivalent emissions compared to R245-fa. Lastly, sensitivity analysis indicates that hybridization ratios of up to 80% can result in a 10.6% reduction in CO2 emissions originating from biomass combustion compared to biomass-only solutions.

Enhancing thermoelectric generation: Integrating passive radiative cooling and concentrated solar heating with consideration of parasitic heat conduction

Thermoelectric generators (TEGs) integrated with solar energy and radiative cooling offer a promising approach for generating power. Concentrated solar energy enhances generation by increasing the solar flux density. However, the relationship between thermoelectric generation and concentration ratio remains not well understood. In this study, the finite element method is employed to investigate the temperature difference across TEGs and the change in generation performance with varying concentration ratios. The results show that due to the mismatch among cooling, heating, and parasitic heat conduction powers, the optimal power generation does not occur at the maximum concentration ratio. As the concentration ratio increases, the temperature difference across the single TEG and its output power initially increase and then decrease. To further improve the power generation performance at high concentration ratios, this study introduces TEG stacking strategy to enhance waste heat recovery by increasing thermal resistance. Outdoor experiments with self-made solar absorptive coating and radiative cooling coating validate this approach, achieving a temperature difference of 64.17 °C and a power density of 135.57 W m−2 by stacking three TEGs, outperforming a single TEG by over three times. This study offers a potential method to continuously power remote off-grid communities and low-power devices.

Techno-economic assessment of vertical axis wind turbine driven RO desalination with compressed air energy storage for remote communities

Renewable energy desalination is gaining much attention in remote off-grid communities facing challenges in accessing clean water. Typically, batteries ensure the continuous operation of small-scale renewable reverse osmosis (RO) desalination systems; however, they are expensive and have relatively shorter lifespans. This study investigates the implementation of a compressed air energy storage (CAES) system coupled with a vertical axis wind turbine (VAWT) to directly drive small-scale RO desalination, potentially replacing batteries and reducing energy conversions. A Simulink model was developed to simulate the performance of a VAWT-driven CAES operating RO units, adaptable for both technical and economic assessments. Parametric studies have identified the optimal configuration. The most cost-effective configuration, utilising eleven VAWTs and a pressure exchanger (PX), achieves a levelised cost of water (LCOW) of 1.63 US$/m3 and an annual water production of 9400 m3. The normalised daily water production per square metre of turbine swept area at the study site is 0.19 m3/m2/day at an average wind speed of 5 m/s. While this configuration has a higher initial capital cost, it yields the lowest LCOW. The CAES system effectively addresses the intermittency challenges of wind energy. This study presents a novel, battery-free VAWT-CAES-RO system as a sustainable desalination solution for remote communities, offering a promising approach to address water scarcity in an environmentally friendly manner.

Assessment of agricultural residue potential for electrification of off-grid communities in the Sawla-Tuna-Kalba District of Ghana

BackgroundThere is a close link between the lack of electricity access and poverty indicators such as illiteracy, high infant mortality, lack of access to health care and malnutrition among others. Most rural farming communities in Ghana lack access to electricity due to the high cost of extending the grid to these communities. This lack of access tends to worsen the gap between urban and rural inhabitants regarding access to education, healthcare and development.MethodsThis study assessed the technical and theoretical potential of agricultural residues in providing electricity to off-grid communities. The study used crop production figures of maize, cassava, millet and groundnut in the Soma and Goyiri farming communities in the Sawla-Tuna-Kalba District to conduct an assessment of the theoretical and technical potential of residues from the crops. The production figures of these crops were obtained from the District Office of the Ministry of Food and Agriculture. Expected electricity demand of households, schools and health centers in the study communities were collected and employed for the projected load demand estimates.ResultsThe study found that 312.23 MWh/day of electricity could be generated from the combined residues of maize, cassava, millet and groundnut from the two communities. This amount of electricity is capable of providing ~ 202 to 263 times the peak electricity demand of the studied communities. Out of the total electricity demand of the two communities, only about 91 kWh/day is needed for use in a school and Community Health Promotion and Services (CHPS) compound, implying that the electricity from crop residues can also help to improve education and health provision in the rural communities.ConclusionIt is concluded that the potential of crop residues in meeting the electricity demand of off-grid communities is enormous. Hence, it must be considered in Ghana’s energy development plans to achieve universal electricity access.

Techno-econo-environmental analysis of sustainable hybrid solar-wind-biogas using municipal solid waste-based grid independent power plant with dual mode energy storage strategy

In the contemporary landscape characterized by escalating energy issues and growing worldwide environmental apprehensions, the transition towards sustainable energy assumes a critical role in enhancing the standard of living. Hybrid renewable energy systems (HRES) are increasingly seen as crucial, particularly in off-grid communities, due to their provision of dependable and sustainable electrical alternatives to conventional fossil fuels. This study evaluates the viability of an autonomous system incorporating dual-mode energy storage, as well as explores the possibilities of converting municipal solid waste (MSW) into biogas to achieve both energy and environmental advantages. This research employs NSGA-II in MATLAB environment, optimizing novel HRES for size and performance where the fundamental goals include cost-effectiveness, health hazard mitigation, and ensuring a reliable electrical supply. The findings indicate that the system under investigation exhibits an ideal energy cost of 0.1393$/kWh, carbon emissions amounting to 184283.1 kg CO2-eq/yr, a health impact of 2.56 × 10−1 DALYs, and an ecological damage footprint of 1.45 × 10−7 species⋅year. The system exhibits a job creation rate of 4.22 jobs per megawatt and attains a human development score of 0.404. Through the utilization of renewable energy sources and advanced storage technologies, it is possible to address the challenges posed by energy and environmental problems.

Multi-temporal assessment of wind, solar, and hydropower resources for off-grid microgrid

For a proposed multi-source all-renewable microgrid in Nigeria’s Middle-belt region, this paper presents a multi-temporal approach to the investigation of the uncertainty in the potential of renewable energy resources. The wind, solar, and hydropower resources for a proposed multi-source all-renewable off-grid community microgrid are considered using an array of probabilistic techniques. The peculiar variances in the location’s climate throughout the year make the more common method of annual models of renewable resources unsuitable for power system planning. Consequently, a more granular model of its renewable resources over time is needed. Therefore, for the chosen location, for each renewable resource, a composite multitemporal maximum-likelihood estimation-based (MLE) probabilistic model for characterization is developed. A total of 39 probabilistic models are developed. Up to 40% improvement in the accuracy of the statistical measures for renewable resource uncertainty was observed. Multi-temporal approach provides more accurate information for power system planning over time than the conventional approach of single aggregate models, especially for hydropower, which is strongly affected by the relatively sporadic occurrence of rainfall. The study shows that solar energy is promising, hydropower potential is seasonal and complementary, and wind potential is low at the location considered in this study.

Assessing the Relative Sustainability of Point-of-Use Water Disinfection Technologies for Off-Grid Communities.

Point-of-use (POU) water disinfection technologies can be adopted to provide access to safe drinking water by treating water at the household level; however, navigating various POU disinfection technologies can be difficult. While numerous conventional POU devices exist, emerging technologies using novel materials or advanced processes have been under development and claim to be of lower cost with higher treatment capacity. However, it is unclear if these claims are substantiated and how novel technologies compare to conventional ones in terms of cost and environmental impacts when providing the same service (i.e., achieving a necessary level of disinfection for safe drinking water). This research assessed the sustainability of four different POU technologies (chlorination using sodium hypochlorite, a silver-nanoparticle-enabled ceramic water filter, ultraviolet mercury lamps, and ultraviolet light-emitting diodes). Leveraging open-source Python packages (QSDsan and EXPOsan), the cost and environmental impacts of these POU technologies were assessed using techno-economic analysis and life cycle assessment as per capita cost (USD·cap-1·yr-1) and global warming potential (kg CO2 eq·cap-1·yr-1). Impacts of water quality parameters (e.g., turbidity, hardness) were quantified for both surface water and groundwater, and uncertainty and sensitivity analyses were used to identify which assumptions influence outcomes. All technologies were further evaluated across ranges of adoption times, and contextual analysis was performed to evaluate the implications of technology deployment across the world. Results of this study can potentially provide valuable insights for decision-makers, nonprofit organizations, and future researchers in developing sustainable approaches for ensuring access to safe drinking water through POU technologies.

Lévy arithmetic optimization for energy Management of Solar Wind Microgrid with multiple diesel generators for off-grid communities

This paper presents an improved optimization algorithm for the energy management of a renewable energy solar/wind microgrid with multiple diesel generators applied to off-grid remote communities. The main objective aims to solve the economic emission dispatch problem with a price penalty factor to minimize the energy cost and the emission level. An enhanced metaheuristic optimization algorithm, Lévy arithmetic algorithm, is applied to improve the searchability for optimal solution compared to the conventional arithmetic algorithm. The Lévy arithmetic method is used for the management of the microgrid and compared to other metaheuristic optimization algorithms for the same application. Comparative analysis demonstrates good cost savings using the Lévy arithmetic algorithm, compared to other optimization algorithms such as the arithmetic algorithm, crow search algorithm, hybrid modified grey wolf algorithm, interior search algorithm, cuckoo search algorithm, particle swarm algorithm, colony algorithm, and genetic algorithm.

Lead-acid battolysers for hydrogen cooking: A comparison with electric cooking for sub-Saharan Africa

A battolyser combines the function of battery and electrolyser in one device, i.e. it provides both electrical energy storage and a means to produce hydrogen. A battolyser with lead-acid chemistry has recently been proposed, and this has potential as a particularly low-cost solution. Here, the battolyser is considered for the production of hydrogen as a cooking fuel (“hCooking”) in sub-Saharan Africa, a region where cooking typically employs polluting fuels (firewood and charcoal). The more conventional approach for decarbonisation of cooking is the introduction of electric cookers (e.g. hotplate, induction hob, pressure cooker) which can be powered by PV and possibly battery storage; accordingly these electric cooking (“eCooking”) systems are considered as the competing decarbonised technology. Multi-objective optimisation is used to design both battolyser and eCooking systems for a notional off-grid community, with solar PV as the main energy source. Objectives are the minimisation of net present cost and lifetime greenhouse gas emissions, and Pareto frontiers are produced to show the play-off between these. Results show that a battolyser system could eliminate 95.6 % of CO2 emissions when compared with a baseline using charcoal, at an annualised cost of $507 per household, over a system lifetime of 20 years. However, eCooking systems appear superior to the battolyser, with the cleanest battery + eCook system achieving 95.8 % emissions reduction at annualised cost $422/household. More generally, hCooking systems are nearly always Pareto dominated by eCooking systems, even under a realistic range of sensitivity scenarios. This result is due to the inherently higher energy intensity of cooking over a flame compared to the eCooking options. Priorities to make the battolyser a more viable solution include extending its lifetime as far as possible, cheaper PV systems, and improved hydrogen burner efficiencies. We also show that eCooking together with some continued use of charcoal may be the cheapest possible cooking solution, whilst simultaneously curtailing 60 % of lifetime greenhouse gas emissions.

Thermal-hydro-mechanical modeling of short-term ground responses due to the borehole thermal energy storage operations in a Canadian subarctic region

Seasonal borehole thermal energy storage (BTES) has been recommended as a strategic technology to make an energy transition in the off-grid communities. However, the running of BTES can create thermal disturbance to the surrounding soil formation and bring a thermal-hydro-mechanical coupled process. This coupled process is particularly significant in less permeable formations, where the clay bound water is abundant. The role of clay bound water on the ground response during thermal storage has not been investigated previously. This study aims to numerically assess the short-term ground response due to the thermal disturbance during BTES operations in a Canadian subarctic region. The numerical analysis is conducted using our in-house developed finite element code. Our numerical results demonstrate the significance of considering bound water dehydration in characterizing the ground heave process during the short-term BTES operation in an over-consolidated soil formation. The ground expansion behavior is due to the high excess pore pressure generated from thermal disturbance. The surface heave is mainly from a poroelastic impact leveraging the release of some in-situ effective stress. The neglect of bound water dehydration will underestimate the magnitude of ground heave.

Integration of very small modular reactors and renewable energy resources in the microgrid

Hybrid microgrids, integrating local energy resources, present a promising but challenging solution, especially in areas with limited or no access to the national grid. Reliable operation of off-grid energy systems necessitates sustainable energy sources, given the intermittent nature of renewables. While fossil fuel diesel generators mitigate risks, they increase carbon emissions. This study assesses the viability of integrating a very small modular renewable energy reactor into a microgrid for replacing conventional diesel generators, substantially curbing greenhouse gas emissions. A comprehensive analysis, including design and economic evaluation, was conducted for an off-grid community microgrid with an annual generation and load of 8.5 GWh and 7.8 GWh, respectively. The proposed microgrid configurations incorporate very small modular reactors, alongside solar, wind, and battery storage systems. MATLAB modeling and simulation across eight cases, accounting for seasonal variations, demonstrate the technical and economic feasibility of case 7. This configuration, integrating modular reactors, photovoltaics, wind turbines, and battery storage, satisfactorily meets load demands. Notably, it boasts a high internal rate of return up to ∼31% and a shorter payback period of around 4 years compared to alternative scenarios.

Optimal sizing of hybrid PV–diesel–biomass gasification plants for electrification of off-grid communities: An efficient approach based on Benders’ decomposition

Nowadays, millions of people in remote areas do not enjoy an uninterrupted power supply due to the lack of connectivity to the main power grid. Under such circumstances, the only feasible way to access electricity is typically local power generation, often relying on diesel engine–generator sets or photovoltaic arrays. However, on many occasions, this configuration does not fully exploit all available local resources, including biomass. Indeed, most isolated areas have access to local biomass production from agricultural activities, which can be used for local electricity generation through gasification. This paper addresses this challenge by developing an innovative optimal sizing tool for hybrid power plants integrating biomass gasifiers, specifically designed for isolated areas with access to local biomass production. The novel approach models the particular features of biomass gasification technologies, including long on/off times or restrictive ramping limits. To this end, an efficient methodology based on representative weeks is proposed, which is combined with a solution strategy based on the multi-cut Benders’ decomposition, thus resulting in a tractable framework that can deal with a huge amount of data efficiently. One of the most salient features of the new proposal is the consideration of local biomass production, which is included in the methodology through an original algorithm. Accordingly, a certain amount of biomass is sourced locally, leading to more accurate and reliable results. The new methodology is applied to a benchmark off-grid community in Ghana. The results demonstrate that the use of gasifiers reduces the project cost notably (by 90%) driven by the reduced biomass cost, which can be supplemented by locally generated biomass from agricultural activities. In addition, this technology constitutes a clean source of energy, reducing the total CO2 emissions by 83% compared to a baseline case in which only diesel generators are used. Moreover, it is demonstrated that biomass gasification can effectively act as base load power generation technology to reliably cover most of the local demand, thereby enabling a clean and inexpensive dispatchable local power generation. Finally, a sensitivity analysis reveals that the economic feasibility of the plant is more sensitive to the biomass cost than the selling price of biochar, resulting in a 33% increment in the total project cost when the price of biomass increases from 0 to 0.4 $/kg. Nevertheless, gasification remains as the predominant power generation technology even under unfavorable prices.

Nuclear microreactors: Status review and potential applications; the Mexican case

Microreactors are a class of small modular reactor with a typical power output up to 10 MWe. Their factory fabricated, transportable, and self-regulating design makes the microreactors suitable for supplying electricity to off-grid communities, emergency situations, and space and naval applications. Likewise, microreactors are appropriate for non-power applications such as hydrogen and synthetic fuels production, high and low temperature process heat, various industries (mining, cement, etc.), district heating, and water desalination. Many microreactor concepts are under development around the world with different nuclear technologies, such as the Micro Modular Reactor, a high temperature gas-cooled reactor; Aurora, a liquid metal-cooled fast reactor; and eVinci, a heat pipe-cooled reactor, among others. A recent market assessment of microreactors, conducted by the Idaho National Laboratory, identifies five potential markets for microreactors: Isolated Operations, Distributed Energy, Resilient Urban, Disaster Relief, and Marine Propulsion. In the case of Mexico, which remains dependent on fossil fuels for its energy supply (oil covers 44% of the energy source, while natural gas covers 38% and coal 3%), all potential markets are attractive to consider deploying microreactors, particularly Isolated Operations and Distributed Energy, due to its industrial sector and remote/isolated communities. Mexico’s mining cement, and iron and steel industries are the major consumers of electricity, which is generated primarily with fossil fuels. Similarly, oil accounts for 99.7% of the energy mix of the national transport sector. Furthermore, isolated regions in Mexico, such as the state of Baja California Sur, which generates its own electricity mainly with natural gas, fuel oil, and diesel, could implement microreactors, not only as a potential solution for their electricity supply, but also to implement cogeneration application as water desalination.

Re-righting renewable energy research with Indigenous communities in Canada

The global call to address climate change and advance sustainable development has created rapid growth in research, investment, and policymaking regarding the renewable energy transition of Indigenous communities. From a rightsholder perspective, Indigenous Peoples' vision of sustainability, autonomy, and sovereignty should guide research on their energy needs. In this paper, we present a multi-method, inductive examination to identify gaps between Indigenous communities' expressed needs and rights, and the questions researchers and policymakers investigate in energy transition research conducted in the context of Indigenous communities located in Canada. We combine a systematic review of the extant literature, a scoping review of the grey literature on off-grid communities by Indigenous and non-Indigenous governments and non-governmental policy bodies, qualitative primary data collected via fieldwork, and an in-depth study of an Indigenous-led renewable energy transition study conducted by Haíɫzaqv Nation's Climate Action Team. We holistically examine these different perspectives and identify emergent themes to recommend ways to bridge the gaps between off-grid renewable energy research and stated Indigenous community priorities. Specifically, we recommend designing equitable research practices, understanding community worldviews, developing holistic research goals, respecting Indigenous data sovereignty, and sharing or co-developing knowledge with communities to align with community priorities closely.

Cost-Effective 3D-Printed Bionic Hydrogel Evaporator for Stable Solar Desalination.

Solar desalination using hydrogel evaporators is an eco-friendly, highly efficient means with natural sunlight for sustainable freshwater production. However, it remains challenging to develop a cost-effective and scalable method to prepare salt-resistant hydrogel evaporators for stable desalination. Here, inspired by tree transpiration and hierarchical porous structure, a 3D-printed bionic hydrogel evaporator (3DP-BHE) is designed for long-term solar desalination. Commercialized activated carbon (AC) is introduced into biomass starch skeleton as a solar light absorber to build 3DP-BHE in a cost-effective fashion ($10.14m-2 of total materials cost). The bionic tree leaf layer for 94.01% light absorption and timely vapor diffusion. The bionic tree trunk layer with 3D printed bimodal porous structure for water transfer, thermal isolation, and salt ions convection and diffusion. With the unique bionic structure, the 3DP-BHE achieves a stable evaporation rate of 2.13kgm-2h-1 at ≈90.5% energy efficiency under one sun (1kWm-2). During the 7-day desalination of 10wt.% brine, a steady evaporation rate of 1.98kgm-2h-1 is maintained with a record-high cost-effectiveness (195.3gh-1$-1) manner. This 3DP-BHE will open significant opportunities for affordable solar desalination systems on multiple scales, from individual households to off-grid communities.