Electricity Distribution Utilities Research Articles

New reward and penalty scheme for electric distribution utilities employing load‐based reliability indices

Electric distribution utilities are required to continuously deliver reliable electric power to their customers. Regulatory utility commissions often practise reward and penalty schemes to regulate reliability performance of utility companies annually with respect to a desired performance targets. However, the conventional regulation procedures are commonly found based on the customer-based standard reliability indices, which are not able to discern the service characteristics behind the electric meters and, hence, fail to holistically characterise the actual impact of electricity interruption. This study proposes a new method to evaluate the load-based reliability indices in power distribution systems using advanced metering infrastructure data. Furthermore, the authors introduce a reward/penalty regulation scheme for utility regulators to provide a reliability oversight using the proposed load-based reliability metrics. The new load-based reliability metric and the reward/penalty scheme proposed bring about superior advantages as the distribution grids become further complex with a high penetration of distributed energy resources and enabled microgrid flexibilities. Numerical analyses on different settings with and without microgrid considerations reveal the applicability and effectiveness of the proposed approach in real-world scenarios.

A Spatial Stochastic Frontier Model with Omitted Variables: Electricity Distribution in Norway

An important methodological issue in efficiency analysis for incentive regulation of utilities is how to account for the effect of unobserved cost drivers such as environmental factors. We combine a spatial econometric approach with stochastic frontier analysis to control for unobserved environmental conditions when measuring efficiency of electricity distribution utilities. Our empirical strategy relies on the geographic location of firms as a source of information that has previously not been explored in the literature. The underlying idea is to utilise data from neighbouring firms that can be spatially correlated as proxies for unobserved cost drivers. We illustrate this approach using a dataset of Norwegian distribution utilities for the 2004-2011 period. We show that the lack of information on weather and geographic conditions can be compensated with data from surrounding firms. The methodology can be used in efficiency analysis and regulation of other utilities sectors where unobservable cost drivers are important, e.g. gas, water, agriculture, fishing.

An Estimation of the Impact of Uninterpretable Power Supply Systems on Electricity Distribution Utility of Pakistan

The power crisis in Pakistan is getting worse day by day. Electricity shortfall has reached upto 5000 MW. Due to power shortage consumers are facing load shedding for more than 6 hrs a day. To get rid of this crisis consumers have opted fossil fueled generators and UPS. Due to excessive availability UPS are more popular than generators. Although, UPS satisfy the need of consumers during power outage hour but due to efficiency constrains these UPS put extra burden on grid. This study estimates the power loss that occurs in consequence of using inefficient UPS. It has been found that about 3.75% of total power provided by the utility is lost during charging and discharging. The research also provides suggestions to eradicate the efficiency losses which occurred as a result of using UPS.

Management of Effective Factors in Components’ Supply Chain on Losses of Electric Distribution System

Restructuring in the electrical distribution utilities, the loss management is one of the critical activities to enhance network efficiency. Accordingly, management of technical loss would be the main target of the asset managers. For loss management, the usual methods of loss calculation and estimation need numerous data which is not used to real networks. In this research, a practical method for loss management is introduced from the viewpoint of components’ supply chain to the network. For this purpose, sub-indictors are extracted using focus group for each process of this chain and their probability distribution functions are calculated. Then, permissible values of sub-indicators are determined by the Delphi method and to calculate new probability functions, the deviation of each process is calculated. Finally, a real network with historical data is used here to study the proposed method. The results illustrate that the most deviation is in the sub-indicator design process about 91% in the viewpoint losses.

Efficiency evaluation of electricity distribution utilities in India: A two-stage DEA with bootstrap estimation

The efficiency of the energy sector in India, the world’s third-largest energy consumer, is becoming an important issue amid growing concerns about global warming. This paper examines the efficiency of electricity distribution utilities in India using panel data from 2005 to 2012. We perform a two-stage data envelopment analysis with a bootstrap estimation, in which bias-corrected efficiency estimates are calculated in the first stage and then regressed on external environmental variables in the second stage. First, we find positive effects of customer structure and population density on the efficiency of utilities. Second, we find efficiency advantages of public utilities in the Indian power distribution sector. However, the interaction between ownership and population density is negative, implying that public utilities are less efficient than private enterprises in high population density areas. Finally, we find that government subsidies are negatively related to the efficiency of utilities.

Input–output performance efficiency measurement of an electricity distribution utility using super-efficiency data envelopment analysis

This paper applies the conventional DEA model and super-efficiency analysis in measuring the efficiency of an electricity distribution utility which involves 12 power lines as DMUs. The input indicators considered are purchased electricity supply and the total length of power lines, while electricity consumed, the number of consumers, and total power losses are the output indicators. The results revealed that 4 out of the 12 power lines are inefficient and thus need to be improved. The model provided a guideline how these inefficiencies may be addressed by means of benchmarking.

Performance evaluation and benchmarking of Indian electricity distribution utilities using data envelopment analysis along with sensitivity analysis

The present study aims to evaluate the relative efficiencies and benchmark of 55 electricity distribution utilities operating in different states in India by applying popular and effective performance evaluation method data envelopment analysis (DEA). Technical, pure technical and scale efficiencies were also computed along with peer to peer comparison of inefficient utilities with efficient ones. Efficiency evaluation results with performance improvement schemes also were provided. The results indicate performance efficiency scores, input and output slack, input and output variable targets, reference group for inefficient DMUs with weights and classification of DMUs on the basis on sensitivity analysis. Based on these results, inefficient utilities can improve their performance by making strategic plans for performance improvement. This paper is one of the few published studies that benchmark the performance of Indian electricity distribution utilities by taking specific parameters of electricity utilities of India. Also, it is one of the first paper in which sensitivity-based classification of Indian electricity distribution utilities is being performed to find out sensitivity of variables.

Análisis Espacio Temporal del Impacto al Sistema de Distribución de Nuevos Tipos de Carga con Alto Consumo de Energía: Caso de Estudio en CENTROSUR con la Cocina de Inducción

Debido a la incursión de nuevos electrodomésticos con alto consumo de energía, la demanda del sector residencial de una Empresa Eléctrica de Distribución puede ser incrementada de forma repentina, afectando la operación de la red eléctrica y, consecuentemente, cambiando los requerimientos de inversión para la expansión de la red.
 En este trabajo se utilizó una metodología compuesta por un modelo espacio temporal y un método de análisis del impacto en los circuitos de bajo voltaje de la red eléctrica. El modelo caracteriza la intención de los habitantes de la ciudad en comprar esta clase de electrodomésticos. Por otro lado, el método determina los nuevos valores de operación, voltajes y la sobrecarga que puede provocar el suministro de la demanda para estos electrodomésticos.
 Los resultados obtenidos proporcionan información valiosa del estado actual de las instalaciones de la Empresa Eléctrica y la tendencia del impacto, que puede causar el suministro de demanda para este tipo de cargas, en los circuitos secundarios del sistema eléctrico.

Performance evaluation and benchmarking of Indian electricity distribution utilities using data envelopment analysis along with sensitivity analysis

Performance evaluation and benchmarking of Indian electricity distribution utilities using data envelopment analysis along with sensitivity analysis

Employing Simple Cost-Sharing Policies to Motivate the Efficient Implementation of Distributed Energy Resources

We consider the optimal design of simple cost-sharing policies to motivate electricity distribution utilities to manage the costs of distributed energy resource (DER) projects. The optimal share of realized cost savings (s) that is awarded to the utility takes a particularly simple form in certain settings. More generally, s can vary with the prevailing environment in subtle and sometimes counterintuitive ways. For instance, s may increase as cost savings become less onerous for the utility to secure and as the utility becomes more averse to risk. Gains from affording the utility a choice among cost-sharing policies typically are minimal.

Optimal Asset Expansion in Distribution Networks Considering Battery Nonlinear Characteristics Expansion optimale des actifs dans les réseaux de distribution en tenant compte des caractéristiques non linéaires des batteries

Asset expansion planning in distribution systems is vital and should be extended to consider utility-scale energy storage systems such as batteries. Unlike other assets, usage parameters such as number of storage cycles and depth of discharge (DOD) have a dramatic nonlinear effect on the lifetime of battery energy storage systems (BESSs). Hence, it is imperative to include the relationship between lifetime, number of storage cycles, and DOD of BESS in the optimal asset planning formulation. This paper presents a new formulation and solution for the optimization problem of asset expansion planning in power distribution systems. The research considers adding new BESS units to existing distribution grids. The nonlinear life-cycling-usage relationship of BESS has been modeled for the first time in the context of asset expansion planning in power systems. The formulation aims at minimizing the annualized cost of the expansion plan while satisfying forecasted demand and other distribution system requirements. The methodology is used to optimally plan for the expansion of 6-bus and 33-bus distribution networks. The results show the effect of considering the life-cycling-usage relationship of BESS on optimal asset expansion plans including the optimal size and capacity of the assets. In addition, the impact of the ratio of off-peak load to peak load on total asset cost is analyzed and reported. It is shown that an annual cost saving of 51.79% is possible via the proposed approach. Findings of this paper will capture the attention of planning and asset management departments of electric distribution utilities.

Genetic Algorithm Based Feeder Reconfiguration and Control of Reactive Power for Loss Reduction

Power distribution network consists of a group of radial feeders which can be connected together by several tie-switches and tie-lines. The power loss reduction in the network is a major concern of electric distribution utilities. Among conventional methods, optimal reconfiguration and capacitor placement are two effective methods which can be applied on the network. In this paper a feeder reconfiguration algorithm is build and present for
 the purpose of power loss reduction in distribution systems. The methodology developed combine optimization technique. The network reconfiguration problem is formulated as single objective optimization problem with equality and inequality constraints. The proposed solution to this problem is based on a general combinatorial optimization algorithm known as genetic algorithm, and the load flow equations in distribution
 system. The GA optimizes the system-switching pattern for losses reduction. Decides the system topology, and considered taken the size and location of capacitor placement in the radial distribution networks. The two selection method used in genetic algorithm, first method roulette wheel
 selection and second method tournament selection. Tests show the different in execution time of the program to arrive the best fitness function.
 The proposed algorithm has been implemented in technical MATLAB package and tested for practical network (48-bus) which is taken from the distribution system of Palestine Street in Baghdad city. Tests show that GA is suitable algorithm as optimization technique, high accuracy, and avoid local minimum by searching in several regions to arrive to the global optimum solution. Thus, the outcome of the study shows an efficient technique to solve the problem of network reconfiguration for loss reduction in the distribution power system.

Using Geographic Information Systems to Develop a Robust Electricity Utility Network

Electricity distribution reform is widely viewed today as fundamental to improving domestic and commercial performance and financial viability in different countries all over the world. Several steps have been taken in this regard to improve the performance by undertaking several measures such as reduction of technical and commercial losses, improvement in load management, strengthening of metering, billing and collection avenues, enhancement of attention towards the quality of electric supply and customer care. The role of Geographic information system (GIS) in electric utility has gained much attention worldwide. Using GIS an electric distribution utility uses a network of physical facilities to provide electric power and energy to customers connected to those facilities throughout a geographical area. Each component of the distribution system (i.e., asset) has a physical location and associated data. So does each customer. In order to design, maintain, operate and manage the electric distribution network it is necessary to utilize the geospatial data. A geographic information system (GIS) is a convenient and powerful way to collect, organizes, maintain and manage this geospatial data and display it on a geographic map. The present study focuses on the use of Geographic information system to develop a robust electricity utility network that helps in distribution system planning, analysis and asset management.

5- Innovation applications at Igdas, a natural gas distribution company operating in the energy sector

In this study, the past, present and the future of innovation process in IGDAS (Istanbul Gas Distribution Industry and Trade Incorporated Company), which has been operating for 30 years as the biggest company of the intercity natural gas distribution sector of Turkey, are mentioned. In this regard, it can be expressed that it is also mentioned in a few published studies that include experiences with regards to collecting suggestions from internal and external resources on job development in the service sector related to electric, water and gas distribution ( utility sector ), and solving some problems, evaluating them, giving feedback, their implementation and awarding stages. In the notice, it was aimed at publicizing the company with its main field of activity, development, and some awards received, and afterwards, its innovation journey starting from the 2000s was explained via a case study approach, step by step, detailed under each title.

Assessing the efficiency dynamics of post reforms electric distribution utilities in Pakistan

The power sector of Pakistan has undergone major reforms since 1994 with the objectives of increasing technical and financial performance of the sector. This study estimates and analyzes post reforms efficiency dynamics of electric distribution utilities from 2006 to 2013. Fixed effects stochastic frontier analysis results indicate that technical efficiency of utilities increased by 4.8 percent. However, total factor productivity experienced a negative growth of 11 percent as all components of index remained negative except for efficiency change. Productivity of electric distribution utilities can be enhanced by adjusting their scales of operation and reducing their size through further horizontal separation.

Improved Regulatory Approaches for the Remuneration of Electricity Distribution Utilities with High Penetrations of Distributed Energy Resources

Under increasing penetration of distributed resources, regulators and electricity distribution utilities face greater uncertainty regarding the evolution of network uses and efficient system costs. This uncertainty can threaten revenue adequacy and challenges both cost of service/rate of return and incentive/performance-based approaches to the remuneration of distribution utilities. To address these challenges, this paper proposes a novel methodology to establish allowed utility revenues over a multi-year regulatory period. This method combines several “state of the art” regulatory tools designed to overcome information asymmetries, manage uncertainty, and align incentives for utilities to cost-effectively integrate distributed energy resources while taking advantage of opportunities to reduce system costs and improve performance. We use a reference network model to simulate a large-scale urban distribution network, demonstrate the practical application of this regulatory method, and illustrate its performance in the face of both benchmark and forecast errors.

Spatial statistical methods applied to the 2015 Brazilian energy distribution benchmarking model: Accounting for unobserved determinants of inefficiencies

In 2015 the Brazilian regulator presented a DEA benchmarking model to set the regulatory operational cost goals, to be reached in four years for 61 electricity distribution utilities. The DEA model uses: adjusted operational cost as the input variable, seven output variables and weight restrictions. Although non-discretionary variables or environmental variables are available in the dataset, the regulator argued that no statistically significant correlation was found between the DEA efficiency scores and the non-discretionary variables. This study evaluates the statistical correlation between the DEA efficiency scores and the available environmental variables. Spatial statistic methods are used to show that the efficiency scores are geographically correlated. Furthermore, due to Brazil's environmental diversity and large territory it is unlikely that only one environmental component is sufficient to adjust inefficiencies across the Brazilian territory. Thus, a new combined environmental variable is proposed. Finally, a second stage model using the proposed environmental variable and accounting for a spatial latent structure is presented. Results show major differences between original and corrected efficiency scores, mainly for utilities located in harsh environments and which originally achieved lower efficiency scores.

Potential Effect and Analysis of High Residential Solar Photovoltaic (PV) Systems Penetration to an Electric Distribution Utility (DU)

The Renewable Energy Act of 2008 in the Philippines provided an impetus for residential owners to explore solar PV installations at their own rooftops through the Net-Metering policy. The Net-Metering implementation through the law however presented some concerns with inexperienced electric DU on the potential effect of high residential solar PV system installations. It was not known how a high degree of solar integration to the grid can possibly affect the operations of the electric DU in terms of energy load management. The primary objective of this study was to help the local electric DU in the analysis of the potential effect of high residential solar PV system penetration to the supply and demand load profile in an electric distribution utility (DU) grid in the province of Agusan del Norte, Philippines. The energy consumption profiles in the year 2015 were obtained from the electric DU operating in the area. An average daily energy demand load profile was obtained from 0-hr to the 24th hour of the day based from the figures provided by the electric DU. The assessment part of the potential effect of high solar PV system integration assumed four potential total capacities from 10 Mega Watts (MW) to 40 MW generated by all subscribers in the area under study at a 10 MW interval. The effect of these capacities were measured and analyzed with respect to the average daily load profile of the DU. Results of this study showed that a combined installations beyond 20 MWp coming from all subscribers is not viable for the local electric DU based on their current energy demand or load profile. Based from the results obtained, the electric DU can make better decisions in the management of high capacity penetration of solar PV systems in the future, including investment in storage systems when extra capacities are generated.Article History: Received July 15th 2016; Received in revised form Sept 23rd 2016; Accepted Oct 1st 2016; Available onlineHow to Cite This Article: Dellosa, J. (2016) Potential Effect and Analysis of High Residential Solar Photovoltaic (PV) Systems Penetration to an Electric Distribution Utility (DU). Int. Journal of Renewable Energy Development, 5(3), 179-185.http://dx.doi.org/10.14710/ijred.5.3.179-185

Recent trends in power system reliability and implications for evaluating future investments in resiliency

This study examines the relationship between annual changes in electricity reliability reported by a large cross-section of U.S. electricity distribution utilities over a period of 13 years and a broad set of potential explanatory variables, including weather and utility characteristics. We find statistically significant correlations between the average number of power interruptions experienced annually and above average wind speeds, precipitation, lightning strikes, and a measure of population density: customers per line mile. We also find significant relationships between the average number of minutes of power interruptions experienced and above average wind speeds, precipitation, cooling degree-days, and one strategy used to mitigate the impacts of severe weather: the amount of underground transmission and distribution line miles. Perhaps most importantly, we find a significant time trend of increasing annual average number of minutes of power interruptions over time—especially when interruptions associated with extreme weather are included. The research method described in this analysis can provide a basis for future efforts to project long-term trends in reliability and the associated benefits of strategies to improve grid resiliency to severe weather—both in the U.S. and abroad.

Efficiency of electricity distribution utilities in India: a data envelopment analysis

The study makes an effort to measure the relative efficiency of electricity distribution utilities (DUs) of 17 unbundled states in India using a Frontier tool, viz. data envelopment analysis. The model with constant returns to scale is applied to evaluate the relative efficiency of different sample DUs. The input-orientation measure has been used to calculate the efficiency score of 40 DUs for the year 2012–2013. It is observed that there is existence of inefficiency in 29 out of the 40 sample utilities. These inefficient utilities have the potential to become efficient utilities by benchmarking against the most efficient utilities. In order to supply the same output, these utilities need to reduce their use of inputs to the level of most productive scale size. The regulators need to pay special attention to enhance the efficiency of these inefficient DUs by exploring alternative approaches like incentive-based regulation.