Off-grid Technologies Research Articles

Transforming Energy Access: The Role of Micro Solar Dome in Providing Clean Energy Lighting in Rural India

Access to affordable and reliable energy sources can substantially enhance the lives of marginalized communities in rural areas. Unfortunately, numerous households in these communities rely upon unclean sources of energy such as kerosene to light the house even during daylight. To address this issue, solar off-grid technology - Micro Solar Dome (MSD) was implemented in various states across India, specifically benefiting the scheduled caste and scheduled tribe communities. The study, across the eight selected states, highlights the advantages of adopting off-grid technologies and their roles in promoting awareness of renewable energy solutions. The survey used purposive sampling to collect community members’ perceptions of the product’s benefits and their awareness of renewable technologies. The results indicated that the utilization of the product not only enhanced illumination levels within households but also contributed to improved safety, increased study hours for children, and facilitated economic activities during the evening hours. Furthermore, the study revealed that education plays a crucial role in adopting solar energy. However, interventions such as awareness programs and hands-on experiences with the products can also greatly enhance awareness and promote adoption in rural areas. Overall, the study provided compelling evidence of the significant and positive impact that small-scale initiatives like the MSD can have on the lives of marginalized communities. It also emphasized the potential of such solutions to empower these communities and improve their overall well-being.

Willingness to pay for solar off-grid lighting in rural India

This paper attempts to quantitatively determine the factors that affect the adoption of solar off-grid lighting products from the experience of using solar study lamps. The discrete choice experiment method is applied where the rural household in the primary survey is asked to reveal their willingness to pay for solar off-grid lighting products like Solar Pocket lamp, Solar Hurricane lamp, and Solar Home Lighting System (SHLS) in the pre-intervention and post-intervention stages. The baseline (pre-intervention) and impact (post-intervention) data helps to check whether exposure to the use of solar off-grid product technology will improve familiarity and boosts confidence, which in turn results in a higher willingness to pay for the products. The data analysis using Tobit regression reveals that the willingness to pay significantly rises in the post-intervention phase in the case of all three products. This study examines the factors influencing ‘base of pyramid’ households' willingness to pay for solar off-grid lighting systems in India. Using data collected from 663 households, it is identified that the money spent on kerosene lighting, electricity reliability, household type, total assets, and knowledge of the health effects of kerosene, the specification of the solar panel, the number of solar lamps, and the functioning status of the study lamp are major determinants of the willingness to pay for solar off-grid technologies.

Rural electrification with hybrid renewable energy-based off-grid technology: a case study of Adem Tuleman, Ethiopia

Rural electrification with hybrid renewable energy-based off-grid technology: a case study of Adem Tuleman, Ethiopia

History (and stories) of off-grid technologies: a reappraisal

History (and stories) of off-grid technologies: a reappraisal

Exploring long-term electrification pathway dynamics: a case study of Ethiopia

The Open Source Spatial Electrification Tool (OnSSET) is extended to provide a long-term geospatial electrification analysis of Ethiopia, focusing on the role of grid- and off-grid technologies to increase residential electricity access under different scenarios. Furthermore, the model explores issues of compatibility between the electricity supply technologies over time. Six potential scenarios towards universal access to electricity in the country are examined based on three pathways; the Ambition pathway sees high demand growth and universal access achieved by 2025, the Slow Down pathway follows a lower demand growth with a slower electrification rate and with a higher share of off-grid technologies, and the Big Business pathway prioritizes grid electricity first for the industrial sector, leading to slower residential electrification. The results show a large focus on grid extension and stand-alone PV deployment for least-cost electrification in case of low grid-generation costs and uninhibited grid expansion. However, in case of a slower grid rollout rate and high demand growth, a more dynamic evolution of the supply system is seen, where mini-grids play an important role in transitional electrification. Similarly, in the case where grid electricity generation comes at a higher cost, mini-grids prove to be cost-competitive with the centralized grid in many areas. Finally, we also show that transitional mini-grids, which are later incorporated into the centralized grid, risk increasing the investments significantly during the periods when these are integrated and mini-grid standards are not successfully implemented. In all cases, existing barriers to decentralized technologies must be removed to ensure off-grid technologies are deployed and potentially integrated with the centralized grid as needed.

A prototype system for the hydrothermal oxidation of feces

To ensure access to safe sanitation facilities in rural communities, cheap off-grid technologies need to be developed to substitute pit latrines and open defecation. In this study, we present a prototype system based on hydrothermal oxidation, which, under optimal conditions, converts a fecal sludge simulant almost completely to CO2 and water, leaving behind only a carbon-poor aqueous phase with the minerals. The prototype has been designed to process the feces from two households. This technology does not only enable a fast and complete conversion, but is potentially also very energy efficient, as the feed does not require any pre-treatment or drying. The system was found to effectively remove 97–99% of the total organic carbon within a reaction time of 600 s under an external energy demand of roughly 4 kWh per kilogram of wet feces by using the oxygen in air as an oxidant. A total of ten experiments with varying injection pressure, total solids content of the feed, and residence time in the reactor were performed to find experimental settings with high conversion. Only when the residence time was decreased from 600 to 300 s did the conversion fall significantly below 97%. To reach a target value of 99.9% TOC conversion, the reactor temperature and/or the residence time must be increased further. To achieve a system applicable in regions with no connection to the energy grid, the thermal loss of the reactor insulation needs to be lowered further to achieve an overall thermally self-sustaining operation.

Electro-Fenton systems for “on-site” sanitary wastewater treatment: Towards an off-grid technology for developing countries

Nowadays, 2.3 billion people in the world (almost a third of the planet´s population) live in communities that lack a sewer system and the financial resources for its installation. In this work, two electrochemical reactors based on the Fenton reaction were evaluated as a tertiary treatment for real sanitary wastewater which was obtained from a pre-treatment using biological processes. The evaluated systems were solar-powered, modular, off-grid operated and tested for open use. The processes consist on treating real sanitary wastewater with an anaerobic biodigester followed by a biological anoxic-aerobic stage and finally using the electrochemical reactors. The solid waste is stabilized using a solar heater and the outcoming aqueous effluent has an average organic matter concentration measured as chemical oxygen demand of 30.6 ± 10.1 mgO2 L−1, biological chemical demand of < 10 mgO2 L−1, total organic carbon of 14.8 ± 3.6 mgC L−1, total suspended solids of < 7.96 mg L−1 and total nitrogen of 36.2 ± 12.1 mgN L−1. The treated water falls below the limits established by the Mexican regulations on concentration of organic matter, total suspended solids, helminth eggs (HE) (< 1 HE L−1) and is close to the limit concentration for fecal coliforms. The goal of this study was to verify the functionality of the prototypes under realistic conditions so that these findings can contribute to the development of a technology for on-site sanitary wastewater treatment systems.

Unwrapping the nexus between the off-grid system and its impact on the islands and remote villages of Ghana

PurposeThis study aims to focus on the nexus between off-grid systems and impacts on islands and remote villages in Ghana by investigating the sources and cost of energy, willingness to pay for electricity and impacts of off-grid energy on the local economy, education, health, social activities, the environment and migration.Design/methodology/approachData were obtained from 110 households; heterogeneous impact analysis of off-grid technologies, average treatment effect by inverse probability weights (IPW) and inverse probability weighted regression adjustment (IPWRA) models were used to analyse the data.FindingsThe sources of energy are gas, kerosene, wood fuel and dry-cell battery. All households in communities with neither electricity nor off-grid system were willing to pay for electricity. Households without off-grid systems (US$8.1) were willing to pay higher amounts per month for electricity. The off-grid technologies improve the local economy, social activities, security, the environment, education and health as well as reduce out-migration.Originality/valueMost of the literature on mini-grid/off-grid systems have been from the engineering and the technical perspective, with a few on the socioeconomic impacts of the systems and consumer engagements. Besides, methods including descriptive statistics, energy technology sustainability framework and qualitative analysis were used in these studies. Nevertheless, the authors used a more rigorous method of the doubly robust inverse probability weighted regression adjustment model and a heterogeneous method to model the impact analysis of off-grid systems.

Towards Use of Persulfate Electrogenerated at Boron Doped Diamond Electrodes as Ex-Situ Oxidation Approach: Storage and Service-Life Solution Parameters

To date, a wide range of synthetic and real effluents have been treated using in situ electrochemically driven BDD-SO4 2−/SO4 ·−/S2O8 2− systems to eliminate persistent organic pollutants and microorganisms. Although reactive sulfate-based species are electrochemically generated in situ with free heterogenous ·OH radicals, SO4 2−/SO4 ·−/S2O8 2− species have a half-life greater than that of the ·OH radicals. However, no information has been published regarding the properties of the oxidant solution after its electrochemical synthesis. Here, an electrochemical BDD-SO4 2−/SO4 ·−/S2O8 2− system was evaluated in terms of solution oxidation power as a function of storage temperature, storage time, and ex situ applicability. Results clearly show that storage temperature has an influence on the storage and service-life of the solutions called fresh-persulfate (25 °C) or cold-persulfate (10 °C). Greater stability in the cold-persulfate solution was observed, as a function of time, and it was effective in degrading organic pollutants as an ex situ oxidation approach, eliminating 80.73%, 79.25%, and 63.25% after 120 min for methyl orange dye, 1,4-benzoquinone (1,4-BQ), and caffeine, respectively. Cold-persulfate solution also proved to be a feasible off-grid technology after 14 days storage. These results contribute to understanding of the fundamentals of sulfate aqueous solutions as precursors of sulfate-based oxidizing solutions and their applications.

Forecasting Solar Home System Customers’ Electricity Usage with a 3D Convolutional Neural Network to Improve Energy Access

Off-grid technologies, such as solar home systems (SHS), offer the opportunity to alleviate global energy poverty, providing a cost-effective alternative to an electricity grid connection. However, there is a paucity of high-quality SHS electricity usage data and thus a limited understanding of consumers’ past and future usage patterns. This study addresses this gap by providing a rare large-scale analysis of real-time energy consumption data for SHS customers (n = 63,299) in Rwanda. Our results show that 70% of SHS users’ electricity usage decreased a year after their SHS was installed. This paper is novel in its application of a three-dimensional convolutional neural network (CNN) architecture for electricity load forecasting using time series data. It also marks the first time a CNN was used to predict SHS customers’ electricity consumption. The model forecasts individual households’ usage 24 h and seven days ahead, as well as an average week across the next three months. The last scenario derived the best performance with a mean squared error of 0.369. SHS companies could use these predictions to offer a tailored service to customers, including providing feedback information on their likely future usage and expenditure. The CNN could also aid load balancing for SHS based microgrids.

Broadening the landscape of post-network cities: a call to research the off-grid infrastructure transitions of the non-poor

Within urban studies, the emerging post-network approach explores infrastructure transitions towards hybrid mixing of grid and off-grid technologies, resources, services, and actors. However, scholarship addressing off-grid transitions in the global south focuses almost exclusively on the poor as non-networked infrastructure consumers. This paper adopts a landscape perspective to consider broader processes of technological, institutional and behavioural change. Using a case study of Day Zero in Cape Town (South Africa), the paper draws on existing studies to demonstrate how the off-grid infrastructure transitions of non-poor households and businesses have potentially catastrophic (but largely ignored) consequences for cities in terms of environmental sustainability, urban governance and citizenship, network quality, and municipal finance. The paper concludes that broadening the landscape of infrastructure analysis, to consider the off-grid infrastructure transitions of the non-poor in the global south, is crucial to address contemporary global challenges.

Factors influencing the sustainability of micro-hydro schemes in Nepal

While renewable energy-based off-grid technologies present a promising solution for providing energy access for remote communities in developing countries, the evidence suggests that their functionality is often problematic. Previous studies have identified some operational and design factors influencing the performance of such off-grid systems. However, these have only involved case studies of single projects and have not sought to use or develop theoretical models to explain what drives sustainability. Qualitative research methods are used in rural Nepal to develop an understanding of how operational, design and other factors influence the performance and sustainability of micro-hydro projects. The findings identify project attributes influencing micro-hydro project performance, and a theoretical model for the sustainable operation of community-managed energy systems is developed. The importance is shown of post-installation support, participatory design to encourage project ownership, and design of a system of sufficient size and reliability that will both support and encourage the uptake of generated power by households and small businesses. Similarly, the analysis revealed various dependence relationships between the sustainability dimensions. Local mini-grid projects with consistent stability of power supply and demand, can maintain a virtuous, self-reinforcing economic cycle within their communities, and thus, achieve more sustainable outcomes.

Design and Manufacture of 1kW Wind Turbine Blades

To meet sustainable development goals and address concerns on climate change, much of the world's energy demand is expected to be delivered from clean alternative energy sources. Small-scale wind turbines have proven to be applicable for off-grid electrification. The objective of this study is to present the details on the design and manufacture of a 1 kW wind turbine blade for specified conditions. Blade element moment theory is adopted in the design of the geometry of the blade. Accordingly, the aerodynamic analysis on NACA 64A410 airfoil resulted in a blade radius of 1.95m, an overall twist angle of 31°, and a gradually tapering chord length of 0.062m at the root and 0.247m at the tip of the blade. Then, the wind turbine blades are manufactured from fiberglass (mat350g), resin, catalyst, and gelcoat. Experimental results reveal the wind turbine blades started producing power at a cut-in wind speed of 3m/s. The maximum power achieved during the testing process was 900W at a hub wind velocity of 9m/s. This is lower than the expected 1000W theoretical power output due to not perfect workmanship in the manufacture of the wind turbine blades. This study will help in building local manufacturing facilities and enhance rural electrification through off-grid technologies.

Closing the void in energy planning modeling: Integrating local realities

Closing the void in energy planning modeling: Integrating local realities

Review of Sustainable Grid-Independent Renewable Energy Access in Remote Communities of India.

In the last decade India has seen an increase in the adoption of solar energy-based technologies by consumers, which has been supported by various government efforts and policies. The rural areas and low-income households that lack a proper electricity supply have emerged as a market for solar off-grid technologies, with private developers increasing their market base slowly in this group. This has promulgated the need to restructure the decentralized energy sector. Existing literature points out the suitability of solar off-grid in such markets; the present study investigates the challenges that have hindered its growth. The study reviews the concept of poverty with respect to the energy sector and analyzes methods of determining poor energy access in the present scenario. It emphasizes the need to understand and reconceptualize policy instruments in order to make solar off-grid a powerful tool in tackling energy demand and providing adequate energy access. It further explores the causes of energy disconnects and how grid-independent solar energy is a technological solution of utmost relevance and in consonance with the idea of sustainable development. For a successful venture, both consumer behavior and marketer objectives are important determinants. The work also provides insights into various models, tools, factors, and social constructs that affect consumer perception and subsequently demand. Over the course of the study, it has been revealed how private players and entrepreneurs are tapping the wrong solar market, leading to misappropriation of solar energy technologies. The suggested improvements and recommendations of the present study from the analysis can serve as a guide for policy makers, technological innovators, and financial stakeholders. Integr Environ Assess Manag 2021;17:364-375. © 2020 SETAC.

Demand for Off-Grid Solar Electricity: Experimental Evidence from Rwanda

AbstractHigh hopes are pinned on market-based dissemination of off-grid technologies to complement expensive grid extension in providing electricity to the nearly 1 billion unconnected people in de...

Self-Sustainable off grid Electric Vehicle EV Charging Station with Integration of Renewable Sources

Electric Vehicles (EV) are the world’s future transport systems. With the rise in pollutions and its effects on the environment, there has been a large scale movetowards electrical vehicles. But the plug point availability for charging is the serious problem faced by the mostof Electric Vehicle consumers. Therefore, there is a definite need to move from the GRID based/connected charging stations to standalone off-grid stations for charging the Electric Vehicles. The objective of this paper is to arrive at the best configuration or mix of the renewable resources and energy storage systems along with conventional Diesel Generator set which together works in offgrid for Electric Vehicle charging. As aconclusion, by utilizing self-sustainable off-grid power generation technology, the availability of EV charging stations in remote localities at affordable price can be made and mainly it reduces burden on the existing electrical infrastructure.

Illuminating the streets, alleys, parks and suburbs of the American City: non-networked technologies, 1870-1920

ABSTRACT During the nineteenth century American cities transitioned from offering minimal services to providing services through networked infrastructures. Among these were street lights fueled largely by coal gas produced by manufactured gas plants and distributed by pipe line and later by electricity, both arc and incandescent. Because of fuel and construction costs, manufactured gas was expensive and uneven, and gas networks were confined to business sectors and affluent neighborhoods. To provide light to dark neighborhoods and suburbs, off-grid stand-alone technologies unconnected to a piped or wired network often supplied illumination. The most common of these were fueled by gasoline and naphtha, byproducts of petroleum distillation aiming primarily to produce kerosene. This pattern was present in many American cities and towns in the late nineteenth and early twentieth centuries. Thus, the case of stand-alone gasoline and naphtha street lights presents an important variation to the advance of the networked city.

Supply and Demand Assessment of Solar PV as Off-Grid Option in Asia Pacific Region with Remotely Sensed Data

The introduction of solar photovoltaic (PV) systems in isolated areas which are far from the main grid has provided energy to non-electrified households. Such off-grid technology is very promising in the Asia Pacific region where increase in population and regional development has brought an increase in energy demand. This paper presents a methodology to assess the available supply of energy from solar PV systems and the corresponding demand from non-electrified areas. Non-electrified high population density areas were extracted using global population distribution and nightlight data, while the suitability of installing solar PV systems in those areas were identified based on slope, land cover and estimated solar PV power output. Moreover, the cost and benefits of installation were estimated based on the levelized cost of electricity generation from PV (LCOEPV) and the percentage in the total household budget that can shoulder the said expense. Lastly, this study also proposed a novel and simple method to extract the power transmission lines (TLs) based on global road network and nightlight data used for defining off-grid areas. Results show that there are three general types of electrification trend in the region with only 11 out 28 countries exhibiting the ideal trend of decreasing population living in unlit areas with increasing GDP. This study also generated maps showing the spatial distribution of high potential areas for solar PV installation in Cambodia, North Korea and Myanmar as case studies. To date, the high estimated household income allotted for PV electricity is still experienced in most countries in the region, but these countries also have high initial generated electricity from PV systems. Outputs from this study can provide stakeholders with relevant information on the suitable areas for installations in the region and the expected socio-economic benefits.

Socio-economic impacts of rural electrification in Tanzania

Recently, penetration rates of solar PV-systems increased drastically in rural Sub-Saharan Africa, and there will be less areas without electricity access altogether. Conversely, mini-grid systems are expected to be key in rural electrification because they allow for higher loads. Eventually, interconnection of national grids with mini-grid systems will gain importance. As a means to quantify the quality of energy access, the Multi-Tier-Framework no longer defines electrification as binary but multi-dimensional. This study compares effects of electrification on households connected to an interconnected mini-grid system with effects on households connected to off-grid energy systems in rural Tanzania. Relying on Propensity Score Matching, the analysis concludes that mean lumen and lighting hours in mini-grid electrified villages are significantly higher. Regarding usage of electrical equipment and expenditures for energy sources, minor differences are detected. However, lighting belongs to the most direct impacts of electrification and assumes an intermediary role in promoting further effects. The case study shows that off-grid technologies are important sources to bridge and narrow the “lighting gap” and can already meet a certain level of rural electricity demand. Pre-grid-electrified statuses and their socio-economic impacts need to be reflected in research as they build the foundation for further electrification measures.