Off-grid Households Research Articles

Exploring Energy Poverty among Off-Grid Households in the Upper Blinkwater Community, South Africa

Exploring Energy Poverty among Off-Grid Households in the Upper Blinkwater Community, South Africa

MATHEMATICAL MODEL AND SIMULATION FOR DESIGNING A COST-OPTIMIZED OFF-GRID HOUSE SOLAR ENERGY STORAGE SYSTEM

Solar power is a renewable energy source suitable for residential usage due to its affordability and the small area required for installation. However, it requires an effective energy storage system that can minimize power outages within a limited budget. This challenge was addressed by analyzing energy storage systems regarding climate and user behavior. In this study, a mathematical model has been developed to design a cost-effective energy storage system for an off-grid household. We utilized the Markov weather process and Monte Carlo simulation, considering various scenarios of available energy supply, energy consumption, and user behavior. In accordance with the outcome, the size and type of battery system from our model minimized power outages throughout the year. We applied our model to a 1600-square foot house in Rayong, Thailand, with the meteorological data and typical electricity loads from user data. For a budget threshold of 40,000 USD, our model suggests that the best battery is Tesla Powerwall+, which results in an average power outage of only around 3 hours per year, outperforming other batteries under identical economic conditions. Additionally, our model can be widely applied to real scenarios by considering a broader range of batteries, environmental impact and available space, and hybrid systems as well.

Assets power solar and battery uptake in Kenya

Solar and battery adoption for households offers many benefits that motivate increased understanding of what drives investment. This paper uses microdata from a household survey in Kenya to investigate factors explaining investment in solar home systems, solar lighting systems, solar lanterns, and solar batteries. Key findings highlight the importance of assets for each investment type. Households are more likely to have a solar home system when they have bank or mobile money accounts, and when they own land with large values. Households are less likely to adopt solar systems when they are unable to afford grid connection, compared to households who are far away from electricity grids. Interaction analysis reveals that off-grid households without a mobile money account in key disadvantaged counties have lower solar home system adoption. A key policy implication is that support could be targeted to households with low levels of assets, in addition to existing support for suppliers.

Optimization of UV-C pulsed radiation strategy for a high-efficiency portable water sterilizer

In many places of the world, the lack of municipal facilities for water sanitation and purification makes self-treatment at a familiar scale, the only realistic solution to ensure continuous access to drinking water. In this context, UV disinfection treatment is a portable and efficient alternative to conventional methods, however, its power need is hindering its implementation in remote off-grid households. This work presents a portable water sterilizer device using UV-C LEDs, conceived for its direct implementation in isolated rural communities. Pulsed radiation operation has been studied as strategy to reduce the device energy demand. Most relevant parameters affecting the device operation and performance, namely voltage, radiation time, frequency and duty cycle; are thoroughly studied using the Design of Experiments methodology to optimize energy consumption and Escherichia coli removal from polluted water. The optimal conditions, found for pulsed radiation, showed a noteworthy reduction of 68 % of the energy consumption while improving the sterilization effectiveness, compared with continuous radiation. Furthermore, the efficiency of sterilization of the optimized prototype was benchmarked against a commercial device using river water samples. The presented prototype achieved higher E. coli disinfection effectiveness using a fraction of the energy consumption. All in all, the presented water sterilization device is an example of a technological improvement which uses energy efficiency as key developing driver while achieving performance requirements. Thus, contributing to the creation of affordable and efficient technological solutions to promote global access to drinking water.

A New Artificial Neural Network Model for the Output Voltage and Power Predictions of Permanent Magnet Generators with Variable Air Gaps

—An artificial neural network (ANN) model is recommended for the analysis and prediction of the output results of a recently designed and constructed generator known as a permanent magnet generator with axial flux. The generator is considered to generate a power scale of P = 3 kW, especially for off-grid household usage far from the network. This machine has an adjustable air gap mechanism, and P = 3 kW is the maximum power; thus, this power can be decreased comfortably by increasing the air gap further to 7 mm. In this case, the maximum power rate can be decreased to P = 1.5 kW according to the experimental confirmation. As a new technique, an ANN approach is introduced for the predictions of voltage and power obtained output for various electrical loads, rotor speeds, and air gaps because it is difficult to get output values for all those machine parameters. In addition, this ANN technique enables one to find the generated voltage and power for specific extremely low air gap values (i.e., 0.2 mm, 0.4 mm, 0.6 mm), which is hard in experimental work due to construction difficulties. The ANN model is used to predict the output values of the generator before any laboratory practice successfully, and the users can determine the correct air gap ranges to their required power regimes for this generator.

Off-grid households’ preferences for electricity services: Policy implications for mini-grid deployment in rural Tanzania

Mini-grids play a critical role in providing electricity to remote, off-grid communities in Sub-Saharan Africa. However, success of mini-grid projects can be hindered by poor cash flows and limited revenue returns. A clear understanding of off-grid households’ preferences for electricity services is a prerequisite for mini-grid stakeholders to set tariff structures and stimulate income-generating power demand to scale up mini-grid deployment. This study conducted a choice experiment survey in two off-grid villages targeted by new mini-grid projects in Tanzania to reveal heterogeneity in households’ preferences for multiple electricity service attributes. We found that households’ heterogeneous preferences were significantly associated with demographic (e.g. gender), socioeconomic (e.g. ownership of TV), and energy-related behavioural characteristics (e.g. charging devices away from home). We suggest that service-based, tiered tariffs and business models can be designed to cater for the heterogenous demands and preferences of different segments of customers. Successful deployment of mini-grids needs to consider the competition from the existing solar home systems and focus on the provision of higher tiers of electricity services. Gender equality issues should be addressed in rural electrification efforts given the significantly greater vulnerability of female-led households to higher electricity fees.

Brokering Gender Empowerment in Energy Access in the Global South

How do energy professionals in the Global South facilitate the brokerage of gender equity and empowerment in energy access? Energy sector professionals, including planners and members of non-governmental organisations (NGOs), are crucial development actors in off-grid contexts. They operate at the intersection between grassroots-level energy access in off-grid household and community buildings and overarching policy frameworks. However, despite their central role, the relationship between their professional practices and gender empowerment in energy access has received little attention. This paper investigates ‘energy brokers’ across Ghana, India, Nigeria and Pakistan based on interviews (<em>n</em> = 86). Subsequent thematic analysis explores these energy brokers’ overarching understandings of gender equity and empowerment, their agency, and brokering practices for energy access (including in relation to emerging energy technologies). Analysis shows ‘differentiated brokerage’ in that energy professionals from the NGOs and the delivery sectors are often better positioned to broker gender equity and women’s empowerment in energy access. However, linkages between equitable access and empowerment need to be better understood, especially at the ‘top’ and go beyond women’s economic productivity. Women’s participation across supply chains of emerging energy-access technology, in energy governance and as energy brokers needs strengthening. <em><strong>Practice relevance</strong></em> Energy professionals occupy an important ‘middle’ position and can help to create changes to overcome gender bias in access to energy. They facilitate the brokerage (understandings, agency and practices) of gender equity and empowerment in energy access in off-grid contexts, including household and community buildings. The evidence from this study shows the performance of energy professionals is critical in facilitating women’s empowerment in energy access. Key recommendations are: (1) energy professionals at the top need to recognise differentiated brokerage across the grassroots–policy spectrum to better identify and equip key actors; (2) energy brokers need to move beyond gender neutrality and economic participation acting on the breadth of women’s empowerment, including psychological dimensions; and (3) women’s participation across energy system transitions needs to be strengthened, with regard to energy supply chains, energy governance and as energy brokers.

Household willingness to pay for improving electricity services in Sumba Island, Indonesia: A choice experiment under a multi-tier framework

Global efforts to improve electricity access in developing countries need to go beyond the simple measurement of electrification rates to address the quality of electricity supply. Households' preferences and willingness to pay (WTP) for electricity supply is important information for policy makers, utility companies, and other stakeholders to plan investment in power infrastructure, design business models, and tackle energy-related social equality issues. However, the existing literature is largely focused on consumers' attitudes towards green electricity, while preferences for improving the quality of electricity supply have not been fully researched, especially in the context of deprived areas in developing countries. Based on the World Bank's Multi-Tier Framework (MTF) for measuring energy access, this study conducted a Choice Experiment on the “Iconic Island” of Sumba in Indonesia to investigate households' preferences for four attributes of electricity access: daily supply hours, frequency of unplanned power-cuts, power capacity of using medium/high-power appliances, and monthly electricity fees. The results reveal that reduction of power-cuts, the most studied attribute of power supply in previous studies, is less significant than other attributes in Sumba. Households connected to the main-grid show higher WTP for improving electricity supply than off-grid households. Heterogeneity in households' preferences is significantly associated with gender, age, education level and household income. We discussed policy implications for penetration of renewable energy, prioritising electrification investment and designing service-based electricity tariffs. We also demonstrated the potential for further application of choice experiment results with the MTF of energy access.

Scalable Microgrid Process Model: The Results of an Off-Grid Household Experiment

The security of national energy systems as well as the transition to a low-carbon future are two hot topics of discussion in the international political arena. Research on the stability of centralized energy systems is currently focused on distributed generation. Developing a scalable microgrid model enabling its massive adoption is one of the safest and feasible ways to solve such problem. The paper aims to fill an existing gap regarding the operation model of microgrids that is a barrier for the large-scale integration of those in the conventional grid network. In the proposed approach the authors identified key processes to be considered when operating microgrids, in the conditions shown through an experimental (simulation) campaign. A three-phase research was performed: (1) systematic literature review to explore the management models of a stand-alone microgrid design and management; (2) a household experiment; and (3) a computer simulation of energy balance for a selected household. We identified eight key processes constituting a scalable microgrid: five core processes, two supporting processes, and one management process. Subsequently, we developed a map of these processes obtaining a microgrid process model for massive adoption. The model of processes can be considered as a repeatable pattern of conduct in the creation and maintenance of microgrids, which their future owners can follow. To support our literature findings, we performed an experiment and a computer simulation of three sub-processes of the (re)design of the infrastructure process: (1) wind turbine selection, (2) photovoltaic power plant selection, and (3) energy-storage selection. Results confirm conditional stability of the analyzed microgrid and the need for cyclical simulation exercises until unconditional stability is achieved. In terms of sustainability, to keep the microgrid permanently in a positive energy balance will require the implementation of all key processes.

Modelling the Costs and Benefits of Modern Energy Cooking Services—Methods and Case Studies

Globally, 2.8 billion people still cook with biomass, resulting in health, environmental, and social challenges; electric cooking is a key option for a transition to modern energy cooking services. However, electric cooking is assumed to be too expensive, grids can be unreliable and the connection capacity of mini-grids and solar home systems is widely assumed to be insufficient. Developments in higher performance and lower cost batteries and solar photovoltaics can help, but they raise questions of affordability and environmental impacts. The range of issues is wide, and existing studies do not capture them coherently. A new suite of models is outlined that represents the technical, economic, human, and environmental benefits and impacts of delivering electric cooking services, with a life-cycle perspective. This paper represents the first time this diverse range of approaches has been brought together. The paper illustrates their use through combined application to case studies for transitions of households from traditional fuels to electric cooking: for urban grid-connected households in Zambia; for mini-grid connected households in Tanzania; and for off-grid households in Kenya. The results show that electric cooking can be cost-effective, and they demonstrate overall reductions in human and ecological impacts but point out potential impact ‘hotspots’. The network analysis shows that electric cooking can be accommodated to a significant extent on existing grids, due partly to diversity effects in the nature and timing of cooking practices.

Meeting energy needs of low-income Sub-Saharan households with a Partially Hybridised Solar Technology (PHST): Experimental performance evaluation based on simulated solar radiation and demand profiles

Renewable energy technologies for sustainable development are rapidly attracting attention across many disciplines despite technical, economic, and social barriers that limit application beyond the laboratory. This study proposes novel semi-automated and automated domestic hot water and electricity demand simulation experiments to evaluate the performance of a proof-of-concept prototype under simulated solar conditions. The prototype is a Partially Hybridised Solar Technology (PHST) which integrates photovoltaic (PV) and low-temperature solar thermal technology for low-cost electricity and domestic hot water supply. The domestic hot water and electrical demand profiles, and the solar radiation utilised during the study represent typical conditions of off-grid households in Sub-Saharan Africa. The prototype delivered a thermal energy supply potential of 2,073±75kJ per day at an average solar thermal conversion efficiency of 29.4±1.0%. The average yield of Direct Current (DC) electricity was 273 Wh per day at a corresponding PV module efficiency of 12.1% but depended on the type of charge controller. These results provide essential baselines for future computer modelling work and techno-economic predictions for Sub-Saharan Africa. The study has important future implications to test standards guiding laboratory-based evaluation of Solar Home Systems (SHSs) for electricity and domestic hot water.

ECONOMIC FEASIBILITY ANALYSIS OF OFF-GRID PV SYSTEMS FOR REMOTE SETTLEMENTS IN BHUTAN

Through rigorous rural electrification projects, over 99.97% of Bhutan’s households now have access to electricity, which is predominantly generated from run-of-the-river hydropower plants. Despite this achievement, around 5% of the rural households still do not have access to electricity to meet their cooking load demands and, therefore, they extensively rely on firewood, LPG, and kerosene for cooking purposes. Apart from hydropower, penetration of other renewable sources such as solar and wind power in the country is negligible. Thus, an attempt was made to determine the investment costs of installing PV systems for off-grid households in remote settlements by studying their economic feasibility. The study shows that the initial cost of investment for an off-grid Solar Home System for a rural household is US$1.42 per Wp using polycrystalline PV modules and US$1.55 per Wp using monocrystalline PV modules. The average cost of installing SHS is determined to be US$ 2342.67 per household. The results of analyses indicate that standalone SHS for remote rural households is not financially viable with the current price of electricity supply in Bhutan. However, SHS provides a more cost-effective option than a grid-line extension, which is estimated to cost about US$ 6700 per household for the remaining off-grid settlements.

Estimation of surplus energy in off-grid solar home systems

A recent survey shows that a large percentage of people living in underdeveloped countries do not have access to electricity and are isolated from the rest of the world. Solar energy can help meet the energy demand; however, it has an intermittent nature and relatively high installation cost. The improvement in off-grid Solar Home Systems (SHS) helped many people get access to electricity. However, systems are sized to meet demand on cloudy days, which results in significant wastage of available energy on sunny days, reducing the energy return on investment. This research paper discusses the load requirement of the people living in rural locations. It uses data collected over the last year by collaborating organisations, providing detailed load and solar charging data for off-grid households in Odisha, India. This dataset is analysed to understand the working principle of the installed SHS and the typical daily load profile. Next, the solar data is compared with solar data from online accessible software on an hourly basis and on a 5-minute scale to evaluate the surplus energy. The data shows a significant surplus of solar energy for most of the year that could be used for other low-powered devices. Various methods are discussed to detect surplus energy available during the daytime based on the provided solar data.

Lithium-ion battery-packs for solar home systems: Layout, cost and implementation perspectives

Solar home systems provide effective power supply solutions for off-grid households in developing regions. The standard battery in such systems is currently lead-acid. Nevertheless, recent and foreseeable developments in lithium-ion batteries favor their use in such application, resulting in significant advantages, including light and compact layout, outstanding performance, reliable operation and long cycle life. This paper explores this implementation potential by detailing the engineering aspects of lithium-ion battery-packs for solar home systems, and elaborating on the key cost factors, present and future. It is concluded that the technology is mature for the solar home system market. Furthermore, despite the relatively high initial cost, the lithium-ion battery is competitive at the level of energy storage cost. Ongoing cost reductions will favor the accelerated use of lithium-ion batteries in this application. More favorable conditions to reduce implementation barriers would be created via tailored funding programs and financing schemes.

Technical principles of atmospheric carbon dioxide reduction and conversion: economic considerations for some developing countries

Since natural photosynthesis in our biosphere does not have the capacity to cope with the additional atmospheric CO2 due to combustion of fossil fuels, CO2 has to be actively removed. Efficient methods are currently being developed, but the captured gas has to be dumped in safe and permanent storage environments. Alternatively, it has to be purified before it can be recycled catalytically, using renewable energy, to high-value chemicals as feedstock for the synthesis of polymers, fine chemicals, or in large quantities liquid solar fuels. The combustion of solar fuels is carbon-neutral. If produced at locations where renewable energy is cheap, they become an important economic opportunity. The requirement to achieve a carbon-zero energy supply also for air traffic allows planning for an as yet unknown higher price compared to that of fossil fuels. Use of solar fuels in closed cycle applications may also relieve the energy situation in the large number of off-grid households in rural Africa. The availability of energy, in particular of electricity, is essential for advanced living conditions, prevents migration to urban areas, and therefore protects a rich variation of tribal cultural, religious and social traditions.Graphic abstract

Analysis of Residential Lighting Fuel Choice in Kenya: Application of Multinomial Probability Models

Safe, clean, and affordable modern lighting services are crucial for improving the socio-economic welfare of the underprivileged people in developing countries. However, many of the Kenyan households are deprived of this service, and they continue to use traditional lighting devices to meet their lighting demand. It is essential to understand the determinants which influence the household energy choice to promote the household energy transition from traditional to modern lighting fuels. Therefore, this study examines the determinants of household lighting fuel choice with multinomial probability models using the survey data collected by the Kenya National Bureau of Statistics (KNBS) in 2015/16. The key findings of this study are as follows. First, the results of this study have empirically proven the energy ladder hypothesis as the probability of choosing modern lighting fuel increases as the income, wealth, gender, and education of the household head improves. The energy ladder hypothesis has been confirmed in both cases of the household with and without the choice of grid electricity. Second, different socio-economic determinants for on- and off-grid household fuel choice are identified, which are the location of household, marital status, and household size. This is an important finding which shows that different policy designs are required to promote energy transition in on- and off-grid households.

Trials and tribulations: Lost energy access gains in rural India

Rural electrification has advanced rapidly in many developing countries. Under conditions of poverty and weak infrastructure, however, households face a risk of backsliding. We use two rounds from the ACCESS survey of rural households in six northern Indian states to explore factors that drive losses in household electricity access. About 7% of households with electricity in 2015 lost it by 2018. We identify household wealth and off-grid access as major drivers of lost energy access. A standard deviation's increase in a household's wealth index reduces the likelihood of disconnection by 1.5 percentage points. Off-grid households are 8 percentage points more likely to lose access than grid-connected households. These findings underscore the importance of defending realized gains in countries where household electrification is driven by policy while rural poverty remains prevalent.

Techno-economic assessment of biomass gasification-based mini-grids for productive energy applications: The case of rural India

As the costs of solar PV continuously decrease and pollution legislation imposes less burning of agricultural residues, decentralized renewable energy is increasingly affordable for providing electricity to one billion people lacking access to a power grid. This paper presents a techno-economic feasibility case study of biomass gasification in off-grid and grid-connected mini-grids for community-scale energy application in rural Uttar Pradesh, India. Energy demand data was collected through surveys in a village with irrigation and agro-processing loads and off-grid households and used to construct a seasonal load profile based on statistical methods. This was used to simulate single-source and hybrid mini-grids based on solar PV, biomass gasification and diesel generation using HOMER Pro. Hybrid PV-biomass or PV-diesel systems were found to offer the highest reliability for off-grid power at the lowest cost. Single-source PV was cheaper than biomass gasification, though the cost of electricity is highly sensitive to biomass supply and gasifier maintenance. Both renewable options were around half the cost of diesel generation. The findings held across grid-connected systems with weak, moderate and strong reliability of grid supply. This suggests that biomass gasification-based mini-grids are not cost-competitive with PV unless the two generation sources are combined in a hybrid system, though they require operational testing prior to implementation.

Weathering electricity demand? Seasonal variation in electricity consumption among off-grid households in rural India

We investigate the relationship between energy consumption from standalone PV systems and a factor widely understood as critical to general energy use: weather. Using household level data collected between January 2016 and January 2017 from seven habitations in Uttar Pradesh, India, we employ linear regression models with quadratic time polynomials to estimate the influence of several key weather variables on electricity consumption. The results highlight the substantive influence of seasonal variation on energy demand. With each single degree increase in temperature, electricity consumption increased 5.2-Wh per week on average when controlling for seasonal change. This strong, positive relationship between electricity consumption and temperature indicates that weather is an important consideration for electrification efforts. As current projections indicate average temperatures will continue to rise, off grid system design strategies should consider the potential for electricity consumption to rise as well.

Optimisation of off-grid hybrid renewable systems with thermoelectric generator

This paper shows, for the first time, the optimisation of the electrical supply in off-grid systems by means of hybrid renewable systems (photovoltaic + wind + battery + fossil fuel) including thermoelectric generator (which source of heat is the exhaust gas of a stove used for cooking or heating).The objective is to minimise the net present cost. An advanced battery model and the accurate calculation of the net present cost (including all the costs during the system lifetime) are considered in the optimisation of this kind of systems. The standard simplified model of the thermoelectric generator is used, as more complex models cannot be used in an optimisation framework, where hundreds or thousands of different cases must be simulated (each combination of components must be simulated at least during one year, in 1-min steps). The optimization is carried out efficiently by means of genetic algorithms.The method has been applied in the optimisation of two cases of low consumption off-grid households (Cambodia and Norway). Thermoelectric generator (costing €8/W) is part of the optimal solution in the case of Norway. In Cambodia, to be part of the optimal system, acquisition cost of the thermoelectric generator should be reduced by 25%.