ATC with ZIP load model – A comprehensive evaluation with third generation FACTS in restructured electricity markets

In this paper, an optimal power flow based approach has been applied for multi-transactions in deregulated environment for ATC determination with third generation FACTS devices. The main contribution of the paper is (i) OPF based approach for evaluation of ATC with multi-transactions, (ii) ATC enhancement with third generation FACTS devices viz. Static Compensator (STATCOM), Static Synchronous Series Compensator (SSSC), and Unified Power Flow Controller (UPFC) for intact and line contingency cases (iii) Impact of ZIP load on ATC determination and comparison of ATC obtained with ZIP load model and constant P,Q load model, (iv) Comparison of ATC obtained with DC/AC-PTDFs based method along with FACTS devices for comparison. The results have been determined for intact and line contingency cases taking simultaneous as well as single transaction cases for IEEE 24 bus RTS.     

Reducing electricity prices and establishing electricity markets in China: Dos and don’ts

This article provides recommendations on how to establish effective electricity markets in China while also achieving electricity price reduction goals in the long-term by drawing on the lessons and experiences of the U.S. markets. We begin by discussing the goal and criteria for market reform.     

Decentralized electricity market with transactive energy – A path forward

Discussions about the future decentralized electricity market include concepts such as transactive energy, energy hub, transmission & distribution coordination, and distributional market pricing. As the advent of the smart grid approaches, the design of a realizable market paradigm that can integrate the wholesale market with the retail market and individualized customers calls for solution. This article provides a summary of the insights achieved to date into the transmission/distribution/customer hierarchy, with a focus on the relation between transactive energy and distribution marginal pricing; it also addresses the ongoing challenges and provides suggestions for future work.     

On the measurement and quantification of electricity affordability in the commercial and industrial sectors – A cost burden approach

This paper proposes a novel method to quantifying the affordability of electricity from the perspective of commercial and industrial establishments. While there is a prolific amount of literature on the quantification of electricity affordability from a household’s perspective, there has been no known attempt to quantify affordability from the perspective of the firm. This paper addresses this gap in the literature by proposing a methodology for quantifying electricity affordability that is aligned with the definition of affordability as laid out in the grid modernization literature and is also derived from the principles of profit maximization of a firm. A demonstration of the effectiveness of this methodology was carried out by its application to publicly available data sets covering different sectors and to firms within those sectors. This simple, yet effective tool will allow policy makers to identify disadvantaged sectors (by city and state) and design policy more effectively so as to benefit them.     

A brief statistics and analysis on residential electricity consumption in China

The statistic data of residential electricity consumptionshown in the table P.58 are quoted from the EnergyStatistical Year Book published by the National Statistic Bureau andthe statistics issued by the Ministry of Energy.The reason of the differences between the data from the twosaid sources is that the latter does not include the consumption sup-plied by the local small power sources.From the statistical data we can see that:     

A new electricity consumption record created in Beijing

Power sales of Beijing Power Supply Bureau reached 31 .81TWh in 2000, it was increased by 3.563 TWh over previousyear, or a growth rate of 12.61%. It was the year of highestgrowth since 1978.According to analysis, the high growth rate of electricityconsumption is attributable mainly to natural demand growth,whilst benefited by power marketing intensification.In 2000, the urban and rural residential electricity consumptionamounted to 4.774 TWh, the growth rate was as high as33.56%, ranking …     

What is the state of development of retail electricity markets in the EU?

For our research, which aims to provide a thorough approach to assessing the development of the retail electricity market in the EU, we tested the hypotheses that the number of suppliers in the retail markets of EU member states has increased significantly over the past decade, and that in the same period, the number of suppliers entering the retail markets of EU member states increased significantly with market liberalisation. We also collected data on the number of electricity suppliers to end-consumers in EU member states between 2010 and 2017, and used the Kruskal-Wallis test for verification, which was also used to establish the ratio between electricity consumers and suppliers between 2010 and 2017. A thorough overview of current scientific findings led us to contemplate a possible combination to measure the dynamics and assess the energy market development, since several authors indicate that no method has been fully accepted as standardised for a thorough assessment of the energy market development. Therefore, a combination of indicators to measure the dynamics and assess the energy market development is proposed in the conclusion of this article, which brings important implications for science and specifically for politics and experts.     

Multi-objective mean–variance–skewness model for generation portfolio allocation in electricity markets

This paper proposes an approach for generation portfolio allocation based on mean–variance–skewness (MVS) model which is an extension of the classical mean–variance (MV) portfolio theory, to deal with assets whose return distribution is non-normal. The MVS model allocates portfolios optimally by considering the maximization of both the expected return and skewness of portfolio return while simultaneously minimizing the risk. Since, it is competing and conflicting non-smooth multi-objective optimization problem, this paper employed a multi-objective particle swarm optimization (MOPSO) based meta-heuristic technique to provide Pareto-optimal solution in a single simulation run. Using a case study of the PJM electricity market, the performance of the MVS portfolio theory based method and the classical MV method is compared. It has been found that the MVS portfolio theory based method can provide significantly better portfolios in the situation where non-normally distributed assets exist for trading.     

Congestion management in power systems – A review

In the past few decades, restructuring has overtaken all possible domains including the electric supply industry. Restructuring has brought about considerable changes by the virtue of which electricity is now a commodity and has converted into deregulated one. Such a competitive market has paved way for innumerable participants. This has led to overloading and congestion of transmission lines. Moreover, open access transmission network has ingenerated a more intensified problem of congestion. Thus, congestion management in power systems is germane and of central importance to the power industry. In this paper a review work is carried out to unite all the publications in congestion management.     

South China Power Grid balances power and electricity for next year in advance

This winter and next spring, even in the whole next year, power supply and demand situation will be morer igorous than that this year. It is estimated that the maximum load of South China Power Grid next year will increase by 20% on the basis of year-on-year, power shortage will further enlarge. For this reason, South China Power Grid has been well prepared early and has arranged and balanced the power and electricity for next year in advance.     

A comparison of time-average power losses in insulated-gate bipolar transistors and hybrid SIT–MOS–transistors

Switching of equivalent silicon insulated-gate bipolar transistors, such as carrier-stored trenchgate bipolar transistors (CSTBTs) and hybrid static induction transistor/metal–oxide–semiconductor (SIT–MOS) thyristors (HSMTs), from a blocking state to a conducting state and vice versa is numerically simulated in two dimensions. It is shown that on–off switching losses in an HSMT are greater than in a fully equivalent CSTBT. Thus, time-average power P that dissipates in an HSMT becomes smaller than the power in the equivalent CSTBTh only at a long current pulse duration. However, a decrease in lifetime τ₀ of nonequilibrium charge carriers in an SIT makes it possible to significantly reduce HSMT switching losses while maintaining its advantage in the on state. Consequently, for each set of CSTBT parameters, such τ₀, it can be selected in the almost equivalent HSMT that power P dissipating in the HSMT will be smaller than the power in the equivalent CSTBT in any given range of amplitude J _a and duration T _on of the current pulses.     

The times they are a changin’: Current and future trends in electricity demand and supply

The increasing penetration of variable renewable electricity generation in Australia’s National Electricity Market over the past decade has led to a sustained change in the shape of electricity demand. In particular, intra-day demand has become more volatile, with demand in some Australian regions increasingly resembling the widely-cited ‘duck curve’ or more appropriately the ‘emu curve’. The changes in demand have, in turn, economically driven out generators whose technical characteristics are ill-suited to supplying this demand profile: high capacity-factor, slow-start plant. In this article, we describe the changes to date in the profile of electricity demand, and draw on other studies to argue that these trends are likely to accelerate going forward based on projected future uptake of variable renewables. In combination with technological and policy developments, these trends imply that flexible plant, such as peaking gas, hydro, and dispatchable storage, are likely to be better suited to the changing profile of demand, in contrast to slow-start and relatively inflexible technologies such as coal and combined-cycle gas plants. These trends are based on the flexibility of different generation technologies and their interaction with emissions considerations.     

Default service pricing – The flaw and the fix: Current pricing practices allow utilities to maintain market dominance in deregulated markets

Utility default service has been priced incorrectly for two decades. Incumbent utilities serving as default service providers for both electricity and gas allocate few to no “costs to serve” to default service rates. The indirect costs not allocated include billing, customer care, enrollments, metering, and other overhead and add up to billions of dollars annually. These costs are paid in distribution rates. The resulting rate for utility-provided default service is a below-market price, allowing the utilities to maintain dominant market positions in the retail markets for residential and small commercial customers. This pricing practice distorts the relevant retail electric and gas markets and harms customers and the markets. NARUC cost allocation guidelines advocate that the cost of utility resources used in the provision of default service should be allocated to that service. This paper presents a Default Service Equalization Adjustment Mechanism (“D-SEAM”) that when deployed properly, will provide the default service utilities with a tool to allocate an appropriate amount of costs to default service rates and then adjust that allocation on a monthly basis to ensure the distribution utility is made whole financially as customers migrate off of default service. Without an appropriate allocation of cost to default service, incumbent utilities will maintain a dominant market position in the retail markets for residential and small commercial customers as a result of the significant subsidy provided by the distribution rates. Utilities should adopt, and/or the regulators should compel the adoption of a complete and appropriate allocation of costs to default service. It is only with this allocation that customers will be able to reasonably compare market offerings.     

Rooftop solar adoption among populations and markets outside the US and Europe–A case from Pakistan

With substantial decrease in the cost of renewable energy technologies (RETs), governments around the world stepped up efforts to transform the ways energy is produced, and the manners it is consumed. Focusing on attainment of SDG-7 through clean energy transition, the aim has been to achieve energy security as well as energy equity while reducing dependence on energy imports. Although ongoing technological breakthroughs and maturity offers promising opportunities, many developing nations are grappling with intertwined socioeconomic dynamics and policy prioritization. Under the resource-constrained financial situation, Government of Pakistan adopted prosumers’ approach to harness year-round available solar energy. Regulatory measures were accordingly instituted, and the electricity distribution companies (DISCOs) were instructed to facilitate people in becoming prosumers. The adoption rates were however well short of the desired outcomes. Besides cultural and socioeconomic dynamics, human interaction with technology, and their level of awareness about related policy parameters play critical role in the technology adoption. In part, this realization led Institute of Policy Studies (IPS) Pakistan to conduct a survey on the consumers’ willingness for taking up the prosumers’ role and, on the parameters contributing to their decision e.g., economic conditions, energy quality and reliability, relevant government policies, and their level of awareness about going solar. Utilizing data from the IPS survey, this study explored the linkage between consumers’ inclination to install solar energy systems and their awareness about solar photovoltaics (PV) technology, the cost factor and relevant government policies. The study revealed significant correlation between target populace’s awareness level and their willingness to become prosumers, highlighting the need for taking policy measures to enhance public awareness on relevant aspects of roof-top solar (RTS) for their due contribution towards sustainable energy solutions in Pakistan.     

Power Electronic Converter Configurations Integration with Hybrid Energy Sources – A Comprehensive Review for State-of the-Art in Research

Abstract

The electricity demand is increasing day by day. On the other side, fossil fuels are depleting at a higher rate. The abundantly available renewable energy sources like solar, wind, and fuel cells are becoming popular sources of energy. But due to the intermittent availability of these renewable energy sources, two or more energy sources are integrated together. Power electronic converters are used for integrating different energy sources. Various power electronic converter (PEC) topologies have been proposed and analyzed in detail to control maximum power point, voltage, frequency, and harmonic distortions. Each of these configurations will differ in its topology and operating principle. The objective of this paper is to present a comprehensive review of various aspects of PEC configurations available for integration of renewable energy sources by systematization into three groups (AC shunt coupled, DC shunt coupled, and hybrid coupled systems). Emphasis is also given to coordination power control, maximum power point, and grid integration challenges related to the hybrid energy system. Furthermore, a general, system modeling of solar, wind, and grid integration is presented here to give an overall picture of a hybrid renewable energy system.     

Public charging infrastructure in Japan – A stochastic modelling analysis

Electric vehicles (EV) are treated as a breakthrough technology in the automotive market. The novelty of this technology also implicates that the incidence of these vehicles worldwide is still low. An important issue regarding EVs is the existence of proper charging infrastructure as waiting at charging stations due to an inadequate number of chargers can discourage EV owners. However, as the number of EVs and charging stations are low at present, real world experience is not available, so computer simulations are required for the planning of such charging stations.We developed a stochastic model in this paper that includes driving and charging behaviour of EV owners in Japan. The model is based on Monte Carlo methods and was implemented in MATLAB. We conducted simulations with this model to find out whether the existing infrastructure is adequate for the charging of a large number of EVs. The results indicate that Japan is well prepared for an increase in plug-in vehicles (PHEVs) in the near future: currently the country has 6 fast chargers for 100 electric cars and for this ratio - on average -, waiting probability at DC (direct current) fast chargers ranges lower than 5%, which is an acceptable value for EV owners. If, however, the ratio decreases, waiting probability increases exponentially.     

Novel economic modelling of a peer-to-peer electricity market with the inclusion of distributed energy storage—The possible case of a more robust and better electricity grid

Current electricity distribution systems allow prosumers to sell their surplus electricity back to the Distributed Network Operator (DNO). The export tariffs at which these sell-backs take place are considerably lower than the feed-in tariffs, offering little incentive to prosumers to sell their surplus energy. A peer-to-peer (P2P) electricity market where consumers and prosumers can interact by selling and buying energy between them at a premium rate that is lower than the standard feed-in tariffs but higher than the export tariffs is proposed. Such a system was modelled to process transactions every 20 s, and a simulation tool was created to obtain the total daily money flows between a consumer-prosumer pair. The inclusion of a Distributed Storage System (DSS) is also considered in the modelled system and simulation. The simulation results showed that the inclusion of a DSS is always beneficial for all parties in economic terms: consumers could save up to 6.4 % on the cost of their electricity while prosumers could save up to 49.1 %. A DSS could generate an income flow for the DNO of up to 6.9p/day per each consumer-prosumer pair.     

In vivo comparison of atherosclerotic plaque progression with vessel wall strain and blood flow velocity in apoE−/− mice with MR microscopy at 17.6 T

Object  At present, in vivo plaque characterization in mice by MRI is typically limited to the visualization of vascular lesions with no accompanying analysis of vessel wall function. The aim of this study was to analyze the influence of atherosclerotic plaque development on the morphological and mechanical characteristics of the aortic vessel wall in a pre-clinical murine model of atherosclerosis. Materials and methods  Groups of apolipoprotein E-deficient (apoE^−/−) and C57BL/6J control mice fed a high-fat diet were monitored over a 12-week time period by high-field MRI. Multi-Slice-Multi-Spin-Echo and Phase-Contrast MRI sequences were employed to track changes to aortic vessel wall area, blood flow velocity and distensibility. Results  After 6- and 12-weeks, significant changes in vessel wall area and circumferential strain were detected in the apoE^−/− mice relative to the control animals. Blood flow velocity and intravascular lumen remained unchanged in both groups, findings that are in agreement with the theory of positive remodeling of the ascending aorta during plaque progression. Conclusion  This study has demonstrated the application of high-field MRI for characterizing the temporal progression of morphological and mechanical changes to murine aortic vasculature associated with atherosclerotic lesion development.     

Including electricity imports in California’s cap-and-trade program: A case study of a border carbon adjustment in practice

This article examines the inclusion of electricity imports in California’s cap-and-trade program. Having struggled to prevent the circumvention of the compliance obligation for imported electricity, policymakers weakened the policy’s environmental effectiveness during implementation. Drawing on empirical data, this case study finds that political opposition from utilities led to this policy outcome. The reason behind this opposition lay in concerns about regulatory uncertainty and the policy’s effectiveness in achieving emissions reductions.     

Thevenin’s equivalent based P–Q–V voltage stability region visualization and enhancement with FACTS and HVDC

Voltage source converter based Flexible Alternating Current Transmission System (FACTS) devices are considered to be key technology to alleviate voltage instability. This paper examines the enhancements in feasible operating P–Q–V space with FACTS and HVDC. Thevenin’s equivalent at the load bus is applied to draw P–Q–V curve (shows the boundary of the maximum real, reactive power and the minimum voltage magnitude) and area of voltage stability region (AVSR) in a three-dimensional diagram. A visualization framework for voltage stability region in MATLAB environment is implemented to study the impact of FACTS (SVC, STATCOM, and TCSC) and HVDC. The best possible location of shunt controllers is obtained using AVSR and index ‘L’. The line stability indices are calculated and compared to verify the weakest line for installation of series controllers. The inclusive study has been performed on IEEE-14 and IEEE-30 bus systems. The results show the enhancement in area of voltage stability region in all cases with maximum in case of HVDC.