Mini-grids Research Articles

Design and implementation of stand-alone solar home system with electrical fencing

Utilization of off-grid solar PV system is one of the availability approaches that can provide electricity to these villages from the remote area or mini grid home load system design for future purposeng to design and application of off-grid solar PV system, valued experience was gotten for popularizing off-grid solar PV system in the remote area of home load . which played an important exemplary role for utilization of solar energy in future. For remote area home/house security is very important. House is one of the basic needs of human being.  A system is to be proposed which will protect the home from animals / birds, as which enter the house. A Solar / electric fence is provided around the home to protect the house from animal /birds/unknown human, so that they should not enter the house. If anyone touches electric fencing then a text message is sent to the owner’s mobile by the use of GSM. This research offers harmless and user-friendly home security for better security.

Design of a Solar PV based Hybrid AC mini grid System with Load Dispatch Centre for an Off- grid Area of Bangladesh

Design of a Solar PV based Hybrid AC mini grid System with Load Dispatch Centre for an Off- grid Area of Bangladesh

Environmental life cycle impact of off-grid rural electrification with mini grids in West Africa

Mini grids for off-grid electrification have attracted high interest in West Africa and a massive deployment is expected in the region in order to achieve Sustainable Development Goal 7 (ensure access to affordable, reliable, sustainable and modern energy for all by 2030). Due to the lack of literature analyzing the environmental impact of mini grid electrification in West Africa, life cycle assessments considering current mini grid technologies in the region (100% PV, hybrid PV-diesel and 100% diesel), battery choice (lead-acid and Li-ion) and village size (small village and large village) were calculated in each of the 15 countries belonging to ECOWAS based on current technology life cycle inventories and economic and solar resource indicators. Results analyzed 18 different life cycle environmental indicators, with 100% PV mini grids outperforming PV-diesel and 100% diesel mini grids in most of these indicators. Indeed, greenhouse gas emissions of 100% PV mini grids were 0.10–0.16 kgCO2eq/kWh and energy paybacks were of 4.3–7.1 years, strikingly lower than the equivalent values for hybrid PV-diesel mini grids (0.14–0.71 kgCO2eq/kWh and 5.9–35.5 years), 100% diesel mini grids (1.14 kgCO2eq/kWh) and the national grid electricity in this region (0.37–0.73 kgCO2eq/kWh).

The Sustainability of Decentralised Renewable Energy Projects in Developing Countries: Learning Lessons from Zambia

Decentralised renewable energy (RE) systems such as solar PV mini-grids (MG) are considered to be a cornerstone for the strategic achievement of the UN’s energy access goals in the developing world. Many of these systems implemented however face substantial technical, financial and social sustainability challenges which are also a recurring theme in the relevant literature. MG analyses however often lack detailed technical or financial data or apply ‘silo-approaches’ as a comprehensive review of MG case study literature presented in this article reveals. Consequently, this study aims to enhance the understanding of RE MG sustainability in the developing context based on the integrated evaluation of the technical, financial and social dimensions of MG operation through empirical data from community surveys on energy use from Uganda and Zambia and two in-depth MG case studies from Zambia. By presenting detailed technical and financial data in combination with energy consumer perception, the study aims to close existing data gaps on sustainable RE MG operation and offers an approach to evaluate and optimise the operational sustainability of an MG in its individual local context. The article finds that the complex rural community ecosystem is a central, but yet undervalued determinant of MG sustainability in rural developing contexts. The mismatch between energy affordability and MG tariffs threatens MG sustainability and the scaling of energy access projects if not addressed specifically during project development and implementation. Consequently, the article calls for a strategic inclusion of community-ecosystem parameters and MG planning based on realistic energy affordability levels and an added value approach that includes dynamic MG financing mechanisms and targeted measures to generate added value through energy consumption as integral parts of RE MG projects.

Constraints of Electricity Mini Off-Grid Systems Diffusion for Entrepreneurship in Rural Areas of Zambia

The low electrification rate of about 52% and an estimated 28% for Africa and Zambia respectively is of concern. There is now a common consensus that renewable energy electricity mini off-grid systems (or simply mini-grids) have a great role to play to reverse the trend especially in remote rural areas that are located farthest from respective national main grids in order to achieve the United Nations Sustainable Development Goal Number 7 which specifically challenges for universal access to sustainable energy by 2030. This study sought to establish the constraints of diffusion for mini-grids intended for entrepreneurial purposes in rural areas of Zambia. The embedded research design; where quantitative data was collected and analysed then followed by collection and analysis of qualitative data was employed for this study. The exponential discriminative snowball sampling technique was used to collect data from a sample of 37 respondents. Likert scales were used to analyse quantitative data in combination with the coefficient of variance and the degree of consensus, while thematic analysis was used to analyse qualitative data. The study established the following constraints of diffusion of mini-grids for entrepreneurial purposes in rural areas of Zambia: high poverty levels, low population density, low profitability of the mini-grids business, substitutes products provide cheap energy sources, fear of the main grid encroachment, high upfront capital expenditure required for setting up the mini-grids business, local taxes, seasonality of business, lack of access to capital finance and limited business ideas, government policy and regulations, ignorance about existence of mini-grids and their benefits, lack of incentives such as capital subsidies, business environment varies depending on speci?c locations and challenging physical geographical conditions. The study conclusively found that; consumer sensitization, the marketing concept and referral marketing are the most effective strategies for promoting diffusion for mini-grids in rural areas of Zambia, supported by the declining costs for renewable energy technologies on the market. The study recommended that sensitization should be intensified since communities respond positively whenever enlightened about the existence of mini grids and their benefits for entrepreneurial purposes. Further, the catchment area for customers deriving benefit from a particular mini-grid should be wide enough by installing mini-grids well far apart to allow attainment of sales critical mass in view of low population density and low profitability in rural areas of Zambia.

Assessment of stand-alone photovoltaic system and mini-grid solar system as solutions to electrification of remote villages in Afghanistan

Afghanistan enjoys huge renewable energy, especially solar resources. Meanwhile, most of the population especially people who live in remote rural areas, still do not have appropriate access to electricity. Poor access to energy has made life more challenging and deprived rustic people from related primary living facilities. To address this grant challenge, considering the high potential of solar energy available in the country, this paper presents a study on design and economic comparison of the two most feasible methods of solar power production for rural areas in Afghanistan. In the first method, a stand-alone Solar Photovoltaic (PV) system has individually been considered in every single house of a village. In this way, energy is produced and consumed in each house itself. While in the second method, energy for the whole village is produced by a micro solar power station in a centralized manner and then distributed through a 0.4 kV islanded Mini grid all around the village. The study is carried out through conventional mathematical relations, based on daily energy demand in a rural household. The result indicates that implementation of the second method is not only best affordable but also more viable and will create other socio-economic opportunities.

State-of-the-Art of Mini Grids for Rural Electrification in West Africa

The current electrification status in West African countries presents rural electrification rates below 40%, national grid losses above 39% with frequent disruptions, and electricity prices averaging $0.35/kWh, up to national values of $0.66/kWh. With this, off-grid systems have gained great attention during the last decade as energy solutions; especially solar home systems (SHS) and mini grids. Nowadays, 385 mini grids with a power of near 30 MW are operating in West Africa, with 95% based on PV. Since 2019, result-based tenders with international aid funding—more effective than previous competitive tenders—seek to install at least 317 new mini grids in Togo, 250 in Nigeria, 100 in Burkina Faso, and two in Mali. Besides, the market for mini-grid energy access start-ups grew from $19 million in 2013 to $339 million in 2018. Despite this recent development in West Africa, research and data for mini grids in this region is scarce, and it is mostly approached from the technological side, with a striking lack of information regarding the social impact. This work tries to describe the present status of research and current operating installations, as well as the main challenges for future development of off grid mini grids in West Africa, which pose as the missing link between SHS and grid extension.

Duck curve leveling in renewable energy integrated grids using internet of relays

Power grids are undergoing deregulation, privatization, and decentralization worldwide. The smart grid allows the integration of clean power renewable energy technologies to the utility grid through mini, micro, and nano grids. Conventional centralized power grids used to rely on fossil fuel-fired power plants which are being replaced worldwide with solar, wind, small hydro, geothermal, biomass, wave, and alternative energy technologies. Installed solar and wind power generation capacity has surpassed 1300 GW in 2020. Solar and wind powers rise during the day and fall during the evening. Consumer demand increases steadily during the evening and peaks after sunset when solar generation becomes zero and wind power falls substantially. Decentralized smart grid faces duck curve limitation on the integration of renewable energy technologies as centralized utilities used to face the peak-hours issue. Smart grid operators have no effective solution of load peaking after sundown except keeping fossil fuel-fired plants on standby to ride through the duck curve. We present a solution to the duck curve problem by integrating smart load shedding devices in micro and nano grids to adjust their demand frugally during peak hours to support the national grid. Information and communication (ICT) technologies that enabled the internet of things (IoT) have been attempted to facilitate smart load shedding in nano grids. ICT enabled voltage transformers (VT) and current transformers (CT) supply signals to heuristic rules based multifunction smart relaying system. Smart meters, instrument transformers, and status monitoring field devices generate a massive amount of data. The research designed an IoT and LabVIEW based software platform to carry out demand-side management. Under frequency (UF) and under-voltage (UV) relaying functions were used to conduct load shedding in nano grids. This nanoscale demand-side management experiment paves the way to ride through utility-scale duck curve setback. This PT/CT data based economic solution performs at nanoscale same as ABB PML 630 load shedding controller. This UF and UV relaying based multifunction relay starts shedding loads when frequency falls below <1% and voltage below 10% of rated values. Our load shedding scheme has successfully functioned on nanoscale 5 kW system. The future study section proposes to integrate big data technologies in-home energy management system (HEMS) through extract, transform and load (ETL) pipeline to import data from PT/CT and circuit breakers (CB) integrated smart meter to transform it according to requirement by loading data into Hadoop “big data” processing platforms for utility-scale load management with help of day-ahead load and weather-dependent renewable power generation forecasting techniques.

APPLIANCE OF CAD / CAM MODELING IN PROSTHETICS OF BONE DEFECTS OF FACIAL BONES

The aim: Improving the ability to restore the shape and function of the bones of the maxillofacial area through the use of their own techniques. Materials and methods: Materials and methods: This research was carry out on the basis of the Department of Surgical Dentistry and Maxillofacial Surgery of Kharkov National Medical University in the Department of Head and Neck Surgery, Kharkov "Regional Clinical Hospital" (2018-2020 years). Examination and treatment of 26 patients, aged from 19 to 55 years, who needed reconstructive surgery to restore the anatomical shape, integrity and function of the maxilla or mandibular jaw. Results: All patients were treated according to the developed method (utility model patent № 145754 "Method of treating traumatic fractures of the maxillofacial area in adults using bone osteosynthesis 3D modeled titanium mini plates"), which consists in 3D modeling, based on previously performed computed tomography, and exploitation individually modeled titanium mini grids and titanium endoprostheses. The experience of this technique shown the advantage of the proposed method not only in the correction of traumatic defects, but also defects of the jaw bones that occur due to the removal of bulky neoplasms. Conclusions: Individual 3D simulated mini grids / plates and endoprostheses, according to the study provide maximum adaptation and restoration of anatomical shape, relief of jaws, their integrity and contour, provide prevention of pathological fractures by stabilizing residual bone tissue (titanium mini grids) serves as a carcass , provide prevention of prolapse (germination) of soft tissues in the area of postoperative bone defect (mini grid does not allow soft tissues to germinate in the area of postoperative bone defect on the outside), which improves functional and cosmetic results. Thus, our proposed method of osteosynthesis using 3D simulated titanium miniplates can be recommended for use in clinical practice.

Pathways to Universal Electricity Access for Rural Communities in Africa

This paper presents results covering the efficiency of appliances to support reduce power needs in both mini grids and upgradeable solar home systems. In addition the research has compared the efficacy of DC vs AC mini grids at different scales. In general, the results indicated that DC mini grids could compete well at sites with a smaller geographical footprint, providing efficient appliances are integrated at system implementation. At the higher ‘tiers’ of electrification, we also present results and experiences from the five e4D solar photovoltaics (PV) mini-grid projects in Kenya and Uganda. The work includes analysis of community engagement, electrical load characterisation, and system operation of the mini grids in rural settings. The results indicate that energy consumption varies significantly between the sites, associated with socio-economic factors, whilst all the villages’ trading centres have experienced varying levels of business growth. Overall outcomes from this research provide clear indications that mini-grid interventions not only invigorate rural communities by enhancing education and health provisions, but are also associated with growth in existing businesses and the creation of new businesses. Therefore, it is recommended that where needed, rural electrification policies be amended to give priority to facilitate and attract investment in decentralized mini grids.

Mini grids and enterprise development: A study of aspirational change and business outcomes among rural enterprise owners in India

Mini grids are increasingly filling the supply gap between government supplied electricity and the requirements of households and enterprises. We present a descriptive analysis of enterprise development within a large mini grid based rural electrification initiative launched in India in 2015. Using data from two surveys conducted with 229 enterprise operators, we explore the change in aspirations among enterprise owners and the impacts of longer duration of reliable electricity on key business outcomes. We find that improved quality of electricity from mini grids leads to a shift towards using mini grids as the primary source of electricity; transition from lighting to productive uses of electricity; and increased aspirational demand for electricity among enterprise operators. Further, we find a positive relationship between increased hours of reliable electricity supply and extended hours of operation and customer footfall, but not with revenue generation. Our findings suggest that mini grids offer an important opportunity for enhancing local aspirations for business development and should be an integral part of policies focused on rural enterprise development.

Rural Electrification: Practical Exposition of Hybrid Solar PV-Wind for Grid Integrated Power Systems in India

Reliable electric power supply is still remained a major problem in rural India. Off grid renewable sources of energy have been applied in the last few years to increase reliability but not succeeding to be realistic because of too high energy costs compared to the national grid. Grid Integrated Minigrids with Storage (Grid Integrated Mini Grids) have potential to provide reliable power supply at reasonably priced by combining Mini-Grids and National Grid services. This research paper analyzed different aspects of the GRID INTEGRATED MINI GRIDS practicability. The feasibility of the use of hybrid - solar Photovoltaic (PV) systems and wind in Grid Integrated Minigrids

Scaling reliable electricity access in India: A public-private partnership model

In this paper, we have examined scaling reliable electricity access in India from two perspectives. First, given past policies, we examine the ability of mini grids to achieve profitability at the unit level as well as potential for scaling. We find that many mini grid developers have shown profitable unit economics and are getting ready to scale; however, they face increased challenges given India's success with 100% electrification. Second, given the experience gained by mini grid operators, we explore collaborative business models that would allow for win-win situations going forward for both distribution utilities and private operators. We use a modification of the existing distribution franchisee model to allow the mini grids operations to manage not only metering and billing but also operation and maintenance as well as generation. We show that it is possible to create business models that not only are appealing from a financial perspective – i.e., in not only improving distribution utility margins but also in meeting private operator criteria of 12% internal rate of return – but also meet multiple policy objectives such as provision of 24-hour electricity reliably and meeting renewable power obligations. However, we also show that the eventual success of these models would critically depend on the distribution utilities and mini grid operators agreeing on elements of these business models, in particular equitable sharing of roles and responsibilities around generation, distribution, operations and maintenance, metering and billing, as well as financial value.

Sustainable development impacts of nationally determined contributions: assessing the case of mini-grids in Kenya

ABSTRACT As of today, access to electricity is still unavailable to 1.1 billion people in the world, half of which live in Sub-Saharan Africa. Projections suggest that this share will increase, leaving millions of people with limited development prospects. Kenya's nationally determined contribution (NDC) to the 2015 Paris Agreement includes a commitment to expand power supply, and in doing so, provide all its citizens with access to electricity. Access in rural areas, where the majority remains unconnected, is planned to be reached through different technologies. These include mini-grids, which are expected to bring multiple sustainable development benefits. However, comprehensive studies looking at synergies and trade-offs between environmental, social, and economic impacts of mini-grids are scarce. Analyzing the expected contribution of mini-grids to targets such as the NDC and the UN Sustainable Development Goals (SDGs) can provide evidence-based decision-support to policymakers, thus promoting well-designed and sustainable rural electrification policies. By using the Initiative for Climate Action Transparency (ICAT) Sustainable Development Methodology, this paper goes beyond the calculation of greenhouse gas (GHG) impacts resulting from access to modern electricity, analyzing also other environmental and socio-economic implications of 146 solar PV mini grids under construction in Kenya. Using specific targets from the SDG framework, the paper presents a combined qualitative and quantitative analysis of the extent to which mini-grids can contribute to the implementation of Kenya's NDC and to sustainable development priorities. Key policy insights The deployment of mini-grids is expected to lower the GHG emissions of the villages currently without access to electricity by 71%. This contributes to 0.4% of the current NDC target for the power sector, in line with the capacity of the systems analyzed. This action is expected to also bring about positive impacts on electricity access, indoor air quality, healthcare, education and economic activities, which are found to contribute to 16 SDG targets. Apart from the economic investment required, possible negative impacts are associated with the electronic waste generated at the end-of-life of the mini-grids. Accounting for sustainable development impacts of policies can increase support among policymakers for climate action, and ultimately raise ambition.

Feasibility Study on Battery Energy Storage System for Mini grid

Feasibility Study on Battery Energy Storage System for Mini grid

Optimal Electrification Planning Incorporating On- and Off-Grid Technologies: The Reference Electrification Model (REM)

In many parts of the world, access to basic electricity services remains a significant challenge. The status quo mode of electrification is central grid extension; however, in many areas, off-grid (OG) technologies like minigrids (MGs) and standalone (SA) systems are more suitable for promoting electricity access under cost constraints. Unfortunately, these opportunities are often overlooked due to the complexities of electrification planning, especially for large areas. Researchers have designed technoeconomic planning tools that can be scaled to cut through aspects of this complexity and be fit to address different places and contexts. This paper describes a computer-based optimization model—named the reference electrification model (REM)—which performs automatic electrification planning and is able to identify lowest cost system designs to most effectively provide desired levels of electricity access to populations of any given size. In doing so, REM determines the most suitable modes of electrification for each individual consumer by specifying whether customers should be electrified via grid extension, OG MGs, or SA systems. For each system, REM supplies detailed technical designs at the individual customer level. We have used this model in real planning activities in sub-Saharan Africa and South Asia. The description of REM’s capabilities is supported by case examples. REM stands apart from other electrification planning models because of its high granularity and its capability to provide concrete plans for a wide range of geographical scales. Because of these benefits, REM has the potential to help rationalize electrification planning and expedite progress toward universal electricity access worldwide.

Chinese Energy Internet Construction Promotes Development of Distributed Renewable Energy Mini Grid

Distributed renewable energy Mini grid is a novel power grid architecture which consists of micro power, load, energy storage devices and control devices. In this paper, status quo and existing problems of distributed renewable energy Mini grid in China are analyzed, and then research contents and key technologies are introduced, a typical distributed renewable energy Mini grid demonstration project is introduced finally. Distributed renewable energy Mini grid will fundamentally change response of Chinese traditional power grid to load growth, reduce energy consumption and improve power system reliability and flexibility.

A Distribution Static Compensator Using a CFNN-AMF Controller for Power Quality Improvement and DC-Link Voltage Regulation

A distribution static compensator (DSTATCOM) is proposed in this study to improve the power quality, which includes the total harmonic distortion (THD) of the grid current and power factor (PF), of a mini grid with nonlinear and linear inductive loads. Moreover, the DC-link voltage regulation control of the DSTATCOM is essential especially under load variation conditions. Therefore, to improve the power quality and keep the DC-link voltage of the DSTATCOM constant under the variation of nonlinear and linear loads effectively, the traditional proportional-integral (PI) controller is substituted with a new online trained compensatory fuzzy neural network with an asymmetric membership function (CFNN-AMF) controller. In the proposed CFNN-AMF, the compensatory parameter to integrate pessimistic and optimistic operations of fuzzy systems is embedded in the CFNN. Furthermore, the dimensions of the Gaussian membership functions are directly extended to AMFs for the optimization of the fuzzy rules and the upgrade of learning ability of the networks. In addition, the network structure and online learning algorithm of the proposed CFNN-AMF are introduced in detail. Finally, the effectiveness and feasibility of the DSTATCOM using the proposed CFNN-AMF controller to improve the power quality and maintain the constant DC-link voltage under the change of nonlinear and linear inductive loads have been demonstrated by some experimental results.

Solar electric cooking in Africa: Where will the transition happen first?

Whilst the rapid spread of solar photovoltaics (PV) across Africa has already transformed millions of lives, it has yet to have an impact on the main energy need of poor households: cooking. In the context of falling global PV prices, recent advancements in battery technology and rising charcoal/fuelwood prices in severely deforested regions, the door is opening for a potentially transformative alternative – solar electric cooking (PV-eCook). While initial investigations focused on solar home systems sized for cooking (cooking device, battery storage, charge controller and PV array), it has since been shown that battery-supported electric cooking (eCook) can also strengthen national, mini, micro and nano grids. This paper presents a multi-criteria decision analysis (MCDA) based methodology, accounting for a wide variety of socio-cultural, political, technical and economic factors which are expected to affect the uptake and potential impact of eCook across a variety of African contexts. It shows the concept has considerable viability in many African countries, that there are significant sizeable markets (millions of potential users), and that within the next five years the anticipated costs of eCook are highly competitive against existing ‘commercialised polluting fuels’.

Barriers to implementation of smart grids and virtual power plant in sub-saharan region—focus Botswana

If Vision 2030 of UN to provide electricity to everyone be achieved, it is essential that over 40% of Botswana’s population living without electricity be looked into from different perspectives and new models. In all smart grid models, it is often emphasized that the residents and the consumers play a vital role in electricity management of Supply and Demand and are expected to be co-producers of electricity. This article looks into the various challenges and success that Botswana has achieved in terms of implementing new technologies and what needs to be done to provide electricity to the rest of the 40% of the community without electricity. This article goes on to describe how a small smart mini grid could serve as a purpose to aid in village development.