Decentralized Electricity Supply Research Articles

THE LIMIT DISTANCES OF CONNECTION OF OBJECTS AND CONSUMERS TO ENERGY SOURCES BY DIFFERENT POWER SUPPLY SYSTEMS

This article is devoted to the development of a methodology for selecting the optimal variant of the power supply system for a remote local facility from the centralized integrated power system. The article proposes and formulates a definition of the term local power facility. 
 The main factors influencing the choice of a power supply system for a remote facility from a centralized power supply system are analyzed, including: the remoteness of the consumer from the centralized power grid, load power, the nature of the loads, its natural and climatic, and socio-economic conditions of location. 
 A classification of power supply systems of local energy facilities has been developed according to such categorical features as: sources of electricity supply, nature of power supply operation, location of the power supply, nature of consumer connection to the power supply, and method of electricity distribution. 
 The article develops the equations of the boundary radii of connection of electrical installations to power sources in the case of centralized power supply from the integrated power system and centralized power supply from the own power plant within the local power facility. Schematic diagrams of power supply of local energy facilities with a detailed description of their elements are constructed. 
 The advantages and disadvantages, as well as opportunities and threats to the development of power supply of local facilities as part of microgrids are presented. The advantages of centralized power supply include the low cost of energy and its much higher quality compared to the energy received from own power plants. The disadvantages of decentralized electricity supply include the high cost of investment in the equipment of own solar, wind or fuel power plants, usually of high capacity and staffed by highly qualified specialists, as well as problems with energy storage and the need to purchase fuel, its delivery and storage in large volumes. 
 The article provides strategic directions necessary for the development and dissemination of energy innovations in Ukraine in the long term.

METHOD OF LOCAL RESTORATION OF SEGMENTS OF INFORMATION SIGNALS

The use of centralized and decentralized electricity supply schemes, the introduction of feedback between the consumer of electricity and its producer led to a rapid increase in information flows at all stages of the functioning of the electricity industry of Ukraine, starting with the production of electricity and before its consumption. This necessitates the processing, storage and transmission of large data sets. On the other hand, the time constraints imposed on information processing and decision-making efficiency, as well as the limited bandwidth of communication networks require effective optimization of information flows in terms of their compression and compact storage, transmission and recovery without loss. At the same time, the determining quantitative and qualitative information parameters are electricity consumption modes and the quality of electric energy, and the main mode parameter for solving many problems of planning, management and carrying out commercial calculations is the graphs of electric load. Based on the analysis of the functional relationships of wavelet coefficients according to the levels of wavelet decomposition, the robot presents a modified reconstruction scheme and developed a model based on which a method of local (segmental) restoration of information signals according to the levels of wavelet detail is synthesized using the example of the electric load graph. In the paper, a model of local recovery of time segments of information signals is proposed and a sequential algorithm of actions synthesized on its basis. This technique allows for effective segmentation of information signals, reduces the duration of mathematical processing, simplifies database analysis, increases the effectiveness of controlling the reliability of initial data recovery by reserving recovery paths with subsequent comparison of results.

Governing Hybridized Electricity Systems: The Case of Decentralized Electricity in Lebanon

ABSTRACT Policymakers see decentralized electricity supply as a way to both decarbonize energy systems and to fill the gap of electricity access in many countries where strong growth leave the grid lagging behind. This article sheds some light on the case of countries such as Lebanon, where diesel-fueled decentralized electricity systems have existed for years and increasingly coexist with, rather than being replaced by, solar powered systems. It is based on a synthesis of public quantitative data and qualitative information gathered through surveys. The article argues that understanding such dynamics involves an analysis, not only of the technological and socioeconomic determinants of the adoption of decentralized energy technologies but also of the political struggles between the various actors, with a particular focus on corporate actors, and wealthy users. In addition, the article shows how different political temporalities play in reproducing or opening the assemblage of technologies and interests that shape the hybridized energy landscape. The article also shows that hybridization has repercussions on the energy configuration as a whole, both in the evolving market share of each technology but also by deeply fragmenting the access to electricity along social and territorial lines and by pushing essential private actors to disconnect from the grid. As a conclusion, the promises of sustainable transitions need to be critically examined in light of these trends.

Electrification seeds – A flexible approach for decentralized electricity supply in developing countries

There are currently more than 500 million people without access to electricity on the African continent alone. With an expected strong population growth and the global goals for reducing carbon emissions, the challenge of providing electricity for all is tremendous. We present an approach that tackles electrification bottom-up in a decentral approach from so-called electrification seeds: Business owners or public institutions that invest in an electricity system to ensure reliable electricity supply for themselves may serve as a seed by also selling electricity in their surroundings via mini- or microgrids. This approach will allow for cheaper solutions due to economies of scale. While private households can also be addressed by simple solutions e.g. solar home systems, the power of the “electrification seed” approach is that it can also provide enough secure power for small and medium enterprises (SME) and thus drive economic development. It is important to address the individual environment of the respective electrification seed, since there is no standard solution. To do so, the method includes an entire toolchain from estimating demands and structures with satellite data and Geographic Information System (GIS) software over employing an energy system model for finding the optimal technological design. As a last step, the viability of the electrification seed concept is verified with an exemplary business plan. The results show positive business cases for the electrification seed and a reduction of electricity costs for end-customers by 11.3 %. Altogether, this gives a very optimistic outlook of the suggested approach to support the great challenge of sustainable electrification for economic growth in developing countries.

ТРАДИЦИОННАЯ И НОВАЯ МАЛАЯ ЭНЕРГЕТИКА В СЕВЕРНЫХ РЕГИОНАХ РОССИИ.

For the North and Arctic regions of Russia the task of the small power generation development is important because there are large areas of expensive decentralized electricity supply (DES) and difficult living conditions. In studying the processes of the small energy development, it is important to detail regional features and economic conditions that determine competitiveness of promising types of energy sources. The article presents the analysis results of the DES of the Russia northern territories on the example of three regions: the Republic of Komi, the Arkhangelsk region, the Republic of Sakha (Yakutia). The analysis aim is to determine the existing prerequisites and barriers to active development of the small power generation in the North. On the basis of the detailed energy-economic indicators and the received generalizations, options for improving the efficiency of autonomous energy supply based on conventional and new small-sized power generation technologies are being considered. The analysis showed that the development of DES zones does not have the institutional incentives and sufficient resource base for qualitative technological modernization. Most of the investment and operating costs of DES in the northern regions are compensated through cross-and budget subsidizations. Traditional diesel generation remains high-cost and low-efficiency, its modernization is carried out at slow rate, the potential of electric and heat energy cogeneration is not used. Renewable energy technologies are not ready for large implementation in local energy systems of the North and Arctic 14of Russia. The renewables projects, implemented over the past five years, are mainly experimental and demonstration. The analysis of the indicators of the "northern" renewable energy projects does not confirm their economic efficiency. The reasons are not only in the high unit investment costs, but also in relatively low utilization rates of the installed capacity (capacity factors) of solar and wind power plants. There is no targeted state support for the development of the efficient small-sized power generation in northern regions.

Differentiation of power supply systems for consumers in the Arctic zone

The article discusses the problems of providing energy supply to consumers in remote regions of Russia, including in the Arctic zone. The necessity of introducing and developing the best available technologies for autonomous energy supply to consumers in the decentralized electricity supply zone, which should be based on the combined use of technologies and reducing cross-subsidization for the long term in the framework of the implementation of a unified state energy policy, is proved. Differentiation of power supply systems of consumers was carried out, according to the results of which it is advisable to pay special attention to the location of the source of electric energy generation. The paper suggests that in the conditions of the Arctic zone it should be as close as possible to the center of energy consumption and the possibility of combined generation of electric and thermal energy.

Repurposing Electricity Access Research for the Global South: A Tale of Many Disconnects

Download : Download high-res image (68KB) Download : Download full-size image Dr. Monyei is currently a research fellow on energy policy and sustainable decarbonization at the University of the West of England, where he works as a researcher and consultant on issues pertaining to sustainable energy systems modeling. Specifically, his research spans core electrical engineering, the social sciences, and computer science and focuses on sustainable development, integration of renewable energy systems, smart grid, applied artificial intelligence, energy efficiency, and the design of public policy to help facilitate easy access to electricity and improvement in the resilience of energization systems. Download : Download high-res image (117KB) Download : Download full-size image Kingsley O. Akpeji received his BSc(Eng) degree in Electrical & Electronic Engineering from the University of Ibadan, Nigeria in 2014 and the MSc(Eng) degree in Electrical Engineering from the University of Cape Town (UCT) in 2019. He is currently a teaching and research assistant at the Department of Electrical Engineering, UCT. His passion for a just energy transition and the alleviation of energy poverty in Sub-Saharan Africa reflects in his research on decentralized electricity supply systems, cost of interruptions of electricity supply to commercial and industrial end-users, and sustainable electrification frameworks and policies.

Electricity sector planning for the Philippine islands: Considering centralized and decentralized supply options

For archipelagic states such as the Philippines, it is important to evaluate centralized and decentralized approaches to electricity supply to ensure that the many and far-flung islands receive affordable, reliable and sustainable electricity. This study compares the feasibility of (I) submarine cable interconnection and (II) renewable energy based hybrid system development for 132 islands. For (I), we conduct a geospatial analysis and use an algorithm to compute the optimized grid outline, taking into account bathymetric models. For (II) we apply an optimization tool that computes for each island the least-cost power generation option, taking into account diesel generator, solar photovoltaic systems, battery storage, and electricity demand. The results indicate that a grid extension of 2239 km submarine cable and 1752 km land cable would be required to connect all of the islands considered. The overall investment under the given cost assumptions amounts to more than 3 billion USD for submarine cable interconnection and more than 700 million USD for a hybridized system development. Nevertheless, submarine cable interconnection is the most economically feasible option for 35 islands and can reduce power generation costs by up to 0.21 USD/kWh. A sensitivity analysis reveals that submarine cable interconnection remains the cost-effective option for most of the identified islands, even with costs increasing by 90%. This study gives an initial assessment of centralized and decentralized electricity supply strategies, and finds renewable energy based hybrid systems most feasible for the majority of islands, and submarine cable interconnection more promising for a few larger islands.

Sensitivity analysis and optimization of a compressed air energy storage (CAES) system powered by a photovoltaic plant to supply a building

Abstract One of the handicaps of the large-scale integration of solar energy is due to its variability and its intermittency. The main way to overcome this issue is the energy storage technology. Knowing the high cost of batteries and their impact on the environment, we simulate a storage system based on compressed air and acting as a battery system. The CAES consists in storing the air at a high pressure in a tank during the period when the energy source is abundant, i.e., cheap, or when the energy demand is low. The compressed air is later expanded through an air turbine which generates electricity during the high demand periods, i.e. when the energy source becomes very expensive for instance. This system could be used for decentralized electricity supply or in an area with no electric grid. In order to evaluate the feasibility of a Compressed Air Energy Storage system coupled to a photovoltaic plant and a building that represents a reduced power demand, a numerical model that reflects the instant behaviour has been built. The system is composed of a photovoltaic power plant, an air compression system, a storage vessel, an expansion module, a power grid and a building. The inputs used are, on the one hand, the climate data such as ambient temperature and the global solar irradiation and, on the other hand, the load curve of a building or of the group of buildings, which has to be supplied by electricity. The overall system optimization has then been performed after having done a sensitivity analysis of the key parameters. This optimization allows us to find the most suitable size for each component of the system: compressor, tank size and photovoltaic area.

A Hybrid Power Plant Based on Renewables and Electrochemical Energy Storage and Generation Systems for Decentralized Electricity Supply of the Northern Territories

A Hybrid Power Plant Based on Renewables and Electrochemical Energy Storage and Generation Systems for Decentralized Electricity Supply of the Northern Territories

РАЗМЕЩЕНИЕ ТЕПЛОВОЙ ЭЛЕКТРОСТАНЦИИ В РАЙОНЕ C ДЕЦЕНТРАЛИЗОВАННЫМ ЭЛЕКТРОСНАБЖЕНИЕМ С УЧЕТОМ МНОГИХ КРИТЕРИЕВ

РАЗМЕЩЕНИЕ ТЕПЛОВОЙ ЭЛЕКТРОСТАНЦИИ В РАЙОНЕ C ДЕЦЕНТРАЛИЗОВАННЫМ ЭЛЕКТРОСНАБЖЕНИЕМ С УЧЕТОМ МНОГИХ КРИТЕРИЕВ

Effects of city size on the large-scale decentralised solar energy potential

To assess the PV-potential on rooftops for decentralized electricity supply in Switzerland, the potential is compared with the following urban-size parameters: (a) urban population, (b) number of buildings, (c) the cumulative building ground-floor area, and (d) the cumulative street length. The coefficients of determination R2 between the PV potential and these factors are: (a) 0.85, (b) 0.86, (c) 0.95, and (d) 0.93. The resulting relations show that 1% increases in factors a-d are associated with the following increases in PV-potential: (a) 0.82%, (b) 0.93%, (c) 0.94%, and (d) 1%, indicating sublinear relations with a-c, but a linear relation with d.

Monitoring system of electricity quality in decentralized electricity supply systems

Considering the ever-growing demand for electricity, there is a need to introduce new generating facilities - distributed energy sources. This in turn leads to the transformation of the centralized electricity supply system - electricity flow goes from the center to the consumer, into an active decentralized system, characterized by new energy and information flows.All this points to the need for a new information infrastructure, which should contain a monitoring system of electricity supply mode parameters. Herewith, it is necessary to note the following. Taking into account technical characteristics of new energy sources (their instability), electricity quality is one of the most significant factors that affect the efficiency of both electrical systems, and consumers.Using existing methods for determining the presence of electricity quality distortion is not acceptable for building real-time monitoring system, based on them. An approach to building real-time monitoring system of electricity quality, which lies in constructing a spatial-temporal distribution of the information signal and the subsequent orthogonal analysis of frequency-temporal changes in its spectral components is presented. Introducing a generalized factor for determining the presence of electricity quality distortion has allowed to carry out its real-time monitoring.

Development and Research of Electric Supply Structure of Remote Populated Areas by Diesel Power Plants

This paper analyses electric power system of diesel power plants. In this paper proposed the solutions for construction of new diesel power plant and its connection to existing power system. Russia is the largest country in the world in terms of territories using decentralized power. These include about 70% of the country area, with a population variously estimated from 10 to 20 million people. These areas are primarily located in the cold or even severe climate, e.g. Siberia, the Far East, and the Far North. The areas with decentralized electricity supply traditionally use instal- lations of small power, i.e. small power plants operating within a certain autonomous power network supplying energy for one or more neighboring communities. The basic fuel for the small-scale power plant in Russia is the diesel, the total amount of which exceeds 47 thousand, and the installed capacity reaches 15 million kilowatts. Electric power system of diesel power plants (DPP) South provides electricity to urban village Kurilsk South, located on a peninsula Kunashir Island (South Kuril Islands) with a population of approximately 6,500 people. Block diagram of the energy complex DPP Southern Kurils, is shown on Figure 1.

Photovoltaic micro-grid in a remote village in India: Survey based identification of socio-economic and other characteristics affecting connectivity with micro-grid

Load prediction is an essential component of the planning process of decentralized electricity supply systems based on micro-grids. However, accurate demand forecasting is a challenging task particularly for rural electrification projects. In this paper, actual operational data of a PV based micro-grid system in Sagar Island of India are analyzed in order to understand the role of different factors affecting households' connectivity, their electricity consumption and potential demands, thereby proposing an approach for planning (and designing) a micro-grid based decentralized electricity supply system. The analysis shows that potential demands for electricity within (as well as outside of) the current reach of the micro-grid are high and future expansion of the system would be effective by taking a 'phased approach’ of rural electrification. The analysis also shows that households with certain socio-economic characteristics have higher probability for connecting with the micro-grid and the relationship can be used to predict additional load requirements in case of grid extensions. Few recommendations for enhancing the connectivity further are also included in the discussion section of the paper.

Research needs for meeting the challenge of decentralized energy supply in developing countries

Scenarios imply that there will still be a considerable percentage of people (16%) without reliable access to electricity, especially in developing and emerging countries, in the year 2030, if ongoing efforts are not intensified. International governance and funding institutions like UNDP and the World Bank consider access to electricity as being fundamental for economic development and poverty reduction. Since the extension of centralized grids is often expensive, different forms of decentralized electricity supply options have gained importance for rural areas and informal settlements during the last 3 decades. Until now, there has been a lack of systematic evaluation of experience with decentralized electricity systems in different cultural and geographic contexts and the transfer of this experience. One reason for this deficiency is that the ‘research community’ for this field is not very clearly defined regarding disciplines and institutions and that there are few institutionalized occasions and forums which enable discussion and systematization of existing knowledge. This article gives a rough overview of the challenges linked to developing and implementing systems of decentralized energy supply under difficult context conditions and the research needs resulting from these challenges. Central means towards success in this domain include embedding the introduction of technical systems in a range of services (e.g. capacity building, maintenance, repair and disposal services, financing schemes), integrating users' needs in their development and implementation, enhancing productive use of electricity by linking energy supply to regional development programs. To be able to deal with the outlined questions, the perspective of decentralized energy supply as socio-technical systems can be helpful. Research desiring to adequately meet the challenges needs to integrate knowledge and perspectives from different disciplines as well as expertise from practitioners in the field in a reflective manner.

Providing electricity access to remote areas in India: Niche areas for decentralized electricity supply

This paper presents the results of a study undertaken for identifying niche areas in India where renewable energy based decentralized generation options can be financially more attractive as compared to grid extension for providing electricity. The cost of delivering electricity in remote areas considering cost of generation of electricity and also cost of its transmission and distribution in the country have been estimated. Considering electricity generated from coal thermal power plants, the delivered cost of electricity in remote areas, located in the distance range of 5–25 km is found to vary from Rs. 3.18/kWh to Rs. 231.14/kWh depending on peak electrical load up to 100 kW and load factor. The paper concludes that micro-hydro, dual fuel biomass gasifier systems, small wind electric generators and photovoltaic systems could be financially attractive as compared to grid extension for providing access to electricity in small remote villages.

The diffusion of energy technology in the rural areas of developing countries: A synthesis of recent experience

This paper provides a synthesis of the experience of attempts to diffuse energy conversion technologies in the rural areas of developing countries. It draws on the experience reported in the literature as well as the five other articles included in this Special Section. The first four articles report the results of research supported under the Rural Energy Technology Assessment and Innovation Network (RETAIN), funded by the International Development Research Centre of Canada. These cover biogas in China, gasifiers in the Philippines, decentralized electricity supply in Argentina, and dual-fuel biogas engines in India. The final paper provides a review of the experience of the diffusion of a number of successful “mature” energy technologies. This introductory paper charts the changing perspective of technology diffusion that has occurred in recent years: the shift from the largely social psychological concerns to concerns about the nature of the technology itself, the political economy of the users and producers, and the more “evolutionary” views of the process of technical change. The evidence is grouped under nine headings: the role of the market and state, diffusion strategies, the performance of the technology, users' needs, political economy, financial returns, the “macro policy environment,” the “system overhead costs,” and adaptation in the light of experience. The paper concludes by drawing from this complex picture of rural technical change a set of basic principles which might guide policy makers and researchers in improving the prospects for the diffusion of rural energy technology.