Independent Transmission System Operator Research Articles

Simulation of Integration of Distributed Generation into Power System Control

The paper deals with modeling of theintegration of distributed generation into the central dispatching system with regard to the electricity market environment. Due to the large number of the relative small unit power of distributed generation the resulting reserve power can achieve a remarkable quantity. However the utilization of these reserves is not obvious because of several technical issues like the cogeneration of heat power, lack of proper informatics, bounds of law about electric energy (LEE) in Hungary etc. An agent based simulation model was developed to discuss the problem. The model consists of the distributed generation units (DG-s) and the DG-concentrator (DGC) which is an interface between DG-s and the independent transmission system operator (TSO). All of them are simulated as autonomous software units suitable for decision making, learning and multi-direction communication. This is a multi-agent system, where the service, control and simulation of stochastic demand variation are easy to study. Several scenarios were discussed regarding the contracts between DG-s and TSO. The financial paragraph of the contract should ensure the willingness of private owned DG-s to provide their reserves for the central control. The results of the simulation help to find the minimum loss operation of the system.

Erratum

The electric reliability council of Texas (ERCOT) is the independent transmission system operator that manages the flow of electric power to serve 90% of the state's electric load. ERCOT's system-wide load peaked at 74,820 MW on 12 August 2019.

Ownership versus legal unbundling of electricity transmission network: Evidence from renewable energy investment in Germany

There are concerns that transmission network companies owned by incumbent vertically integrated energy utilities may conduct anti-competitive discrimination to prevent entry into the electricity market. Different level of transmission network unbundling is implemented in European countries to create competitive electricity market, however, there is little empirical analysis regarding the effects, especially on renewable energy investment. The purpose of this paper is to offer the first causal evidence of the effect of ownership unbundling of a transmission network company from the vertically integrated utility on renewable energy investment, relative to legal unbundling. My geographic quasi-experiment approach exploits the fact that two transmission network firms in Germany have undergone ownership unbundling, while another two firms chose the Independent Transmission Operator model. Constructing panel data of renewable energy power plant capacity installed per municipality from 2008 to 2015, I use difference-in-difference regression and the Tobit random-effects model to identify the impact of ownership unbundling relative to legal unbundling. I find strong evidence that ownership unbundling has little effect on photovoltaics power, onshore wind power, and biomass power capacity increases relative to the Independent Transmission Operator model. This result implies that ownership unbundling and legal unbundling with stronger regulations are both effective for creating independent transmission network companies and for enabling entrants to invest in renewable energy.

Operational Security: The Case of Texas

The electric reliability council of Texas (ERCOT) is the independent transmission system operator that manages the flow of electric power to serve 90% of the state's electric load. ERCOT's system-wide load peaked at 74,820 MW on 12 August 2019.

Prijedlog izmjene odredaba Zakona o tržištu električne energije o dijeljenju poslovnih prostora, IT opreme te IT sustava kao i korištenju istih pružatelja IT usluga i isporučitelja IT opreme između neovisnog operatora prijenosa i ostalih subjekata vertikalno integrirane strukture

Neovisni operator prijenosa jedan je od tri moguća načina odvajanja operatora prijenosnog sustava od ostalih subjekata u vertikalno integriranoj strukturi. Hrvatski operator prijenosnog sustava odvojen je od vertikalno integrirane strukture upravo primjenom modela neovisnog operatora prijenosa. Imajući u vidu skoru potrebu širih izmjena i dopuna domaćega zakonodavnog okvira koji uređuje tržište električne energije u radu se kritički razmatraju određeni problematični aspekti takvog odvajanja, primjerice, pravila o dijeljenju informacijskih sustava (softvera), računalne, mrežne i sigurnosne infrastrukture (hardvera), kao i korištenju usluga istih savjetnika i vanjskih izvođača. Analizom postojećih europskih pravnih pravila kao i zakonskih rješenja usporedivih država članica, rad pruža konkretne de lege ferenda prijedloge za moguće buduće pravno uređenje razmatranih aspekata predmetnog odvajanja neovisnog operatora prijenosa od ostatka vertikalno integrirane strukture.

Oil & gas sector development, as a component of energy of Ukraine

The article analyzes the current state and perspective directions of development of the energy sector of Ukraine in general and the oil and gas complex in particular, which should meet the Plan of measures for the implementation of the stage “Reform of the energy sector (until 2020)” of the Energy Strategy of Ukraine for the period until 2035 “Security, energy efficiency, competitive”. According to the study, at the time the report was released, 80% of the points foreseen by the Plan were not fulfilled. Some legislative initiatives and changes in the regulation of markets of fuel and energy resources are considered. The article analyzes the dynamics of changes in energy consumption. The main trends in the development of the gas and oil products markets are identified. It is found that, despite progress on diversification of supply sources, the country is heavily dependent on imports of energy from The Russian Federation. Separate consideration is given to the transit of natural gas from the Russian Federation to the EU. It is noted that the signed contract is quite compromise and provides a transit pipeline load of less than 40%. The main reasons for the change in the structure of the use of fuel and energy resources, in particular, the practical termination of the use of fuel oil as a boiler-furnace fuel, are also highlighted. The data of the State Statistics Service of Ukraine on the dynamics of prices for natural gas for all categories of consumers, including tariffs for transportation, distribution and trade margin (for household consumers), were also processed. A steady increase in natural gas prices for household consumers was noted during almost the entire analyzed period. Naftogaz Ukraine’s unbinding process was investigated. It is revealed that all necessary steps have been taken to create an independent gas transmission system operator, which took place on January 1, 2020. The implementation of the Energy Community Directives and Regulations in the energy sector has been analyzed, with overall sales less than 50%. The main results of the Stockholm Arbitration between Naftogaz of Ukraine and Gazprom are considered.

Challenges for a compliance officer in the liberalized EU energy market: A case study on the Greek gas transmission system operator

Under the Third Energy Package Directives 2009/72/EC and 2009/73/EC, European energy networks are subject to unbundling requirements which oblige Member States to ensure the separation of vertically integrated energy companies, resulting in division of the various stages of energy supply (generation, distribution, transmission and supply). This paper addresses the challenges that a regulatory compliance officer faces in line with the Third Package provisions. The focus is on the application of the rules on the unbundling independent transmission operator (ITO) model. The present document highlights the Compliance Officer's practice in dealing with certain aspects of the rules on unbundling of Transmission System Operators (TSOs), as laid down in the Gas Directives, such as developing an Effective Compliance Monitoring Program, and setting out practical rules to be observed by staff in relation to non-discrimination, transparency and the handling of confidential information. As a case study, this experience from the Greek Gas TSO, i.e. the Hellenic Gas Transmission System Operator (DESFA), is presented.

A mid-term, market-based power systems planning model

This paper presents a generic Mixed Integer Linear Programming (MILP) model that integrates a Mid-term Energy Planning (MEP) model, which implements generation and transmission system planning at a yearly level, with a Unit Commitment (UC) model, which performs the simulation of the Day-Ahead Electricity Market. The applicability of the proposed model is illustrated in a case study of the Greek interconnected power system. The aim is to evaluate a critical project in the Ten Year Network Development Plan (TYNDP) of the Independent Power Transmission System Operator S.A. (ADMIE), namely the electric interconnection of the Crete Island with the mainland electric system. The proposed modeling framework identifies the implementation (or not) of the interconnection of the Crete Island with the mainland electric system, as well as the optimum interconnection capacity. It also quantifies the effects on the Day-Ahead electricity market and on the energy mix. The paper demonstrates that the model can provide useful insights into the strategic and challenging decisions to be determined by investors and/or policy makers at a national and/or regional level, by providing the optimal energy roadmap and management, as well as clear price signals on critical energy projects under real operating and design constraints.

Implementation of different unbundling options in electricity and gas sectors of the CEE EU member states

The article analyses implementation of the Third Energy Package in the Central and Eastern European countries, members of the EU. The main focus is given to different unbundling options applied for the transmission of electricity and gas: full ownership unbundling, an independent system operator or an independent transmission operator. A general analysis of the scientific literature of the different unbundling options has not revealed serious advantages of the full ownership unbundling option, preferred by the European Commission, in comparison with more simple and less costly option for establishing an independent transmission operator. In the CEE region the countries took different approaches in unbundling electricity and gas companies: if in electricity ownership unbundling was a rather popular approach, in the gas sector only Lithuania has taken the strongest option of unbundling. Existence of a single (or dominant) supplier which in many cases had some shares in the national companies did not allow Governments from the CEE region to choose a more stringent option. Ownership unbundling has significantly increased the gas prices for the consumers in Lithuania: first of all, Gazprom upset with such an inflexible behaviour of the Lithuanian Government left the country with the highest prices in the region, and, second, unbundling and creation of new companies coupled with the reduced demand increased transmission tariffs by 13% and distribution tariffs even up to 30%.

Anticipating and Coordinating Voltage Control for Interconnected Power Systems

This paper deals with the application of an anticipating and coordinating feedback control scheme in order to mitigate the long-term voltage instability of multi-area power systems. Each local area is uniquely controlled by a control agent (CA) selecting control values based on model predictive control (MPC) and is possibly operated by an independent transmission system operator (TSO). Each MPC-based CA only knows a detailed local hybrid system model of its own area, employing reduced-order quasi steady-state (QSS) hybrid models of its neighboring areas and even simpler PV models for remote areas, to anticipate (and then optimize) the future behavior of its own area. Moreover, the neighboring CAs agree on communicating their planned future control input sequence in order to coordinate their own control actions. The feasibility of the proposed method for real-time applications is explained, and some practical implementation issues are also discussed. The performance of the method, using time-domain simulation of the Nordic32 test system, is compared with the uncoordinated decentralized MPC (no information exchange among CAs), demonstrating the improved behavior achieved by combining anticipation and coordination. The robustness of the control scheme against modeling uncertainties is also illustrated.

Correlation and statistical characteristics of aggregate wind power in large transcontinental systems

ABSTRACTStudies have shown that the unpredictability and variability of wind power is reduced in systems with large numbers of geographically diverse wind plants. These effects are caused by the decreased correlation of power output between wind plants as their separation and diversity in terrain increases. One way that system operators have increased geographic diversity is by enlarging balancing areas through the physical or administrative connection of adjacent systems. This strategy can be extended from the regional level to the transcontinental level. As such, it is important to study the correlation and statistical characteristics of aggregate wind power between large, distant systems. This paper analyzes multi‐year historical data from four North American system operators—Bonneville Power Administration, Electric Reliability Council of Texas, Midwest Independent Transmission System Operator and PJM—to see how effective transcontinental interconnection of systems is at enabling wind plant integration. The effects of separation and timescale on correlations of instantaneous and hourly variations are analyzed. The analysis is complemented by a study of a hypothetical transcontinental connection of the systems across yearly, monthly, daily and hourly timescales. The results show that correlations between large systems exhibit similar characteristics as the correlations between individual wind plants, but are somewhat larger in magnitude. The transcontinental system exhibits a close to normal distribution of power output and decreased variability, but there is still appreciable and statistically significant correlation at the longer timescales driven by seasonal and diurnal forcing, as well as synoptic weather systems. Copyright © 2013 John Wiley & Sons, Ltd.

Voltage Coordination in Multi-Area Power Systems via Distributed Model Predictive Control

This paper proposes a coordination paradigm for properly coordinating local control actions, taken by many communicating control agents (CAs), in order to maintain multi-area power system voltages within acceptable bounds. The proposed control scheme is inspired by distributed model predictive control (DMPC), and relies on the communication of planned local control actions among neighboring CAs, each possibly operated by an independent transmission system operator (TSO). Each CA, knowing a local model of its own area, as well as reduced-order QSS models of its immediate neighboring areas, and assuming a simpler equivalent PV models for its remote neighbors, performs a greedy local optimization over a finite window in time, communicating its planned control input sequence to its immediate neighbors only. The good performance of the proposed real-time model-based feedback coordinating controller, following major disturbances, is illustrated using time-domain simulation of the well-known realistic Nordic32 test system, assuming worst-case conditions.

Price effects of independent transmission system operators in the United States electricity market

In 1996, the Federal Energy Regulatory Commission (FERC) sought to “remove impediments to competition in the wholesale bulk power marketplace and to bring more efficient, lower cost power to the Nation’s electricity consumers” through a series of market rules. A product of these rules was the establishment of regional transmission organizations (RTOs) and independent system operators (ISOs) charged with facilitating equal access to the transmission grid for electricity suppliers. Whether these changes in market structure have succeeded in achieving FERC’s goal to provide “lower cost power to the Nation’s electricity consumers” remains an open question. This paper utilizes a panel data set of the 48 contiguous United States and a treatment effects model in first differences to determine whether there have been changes in delivered electric prices as a result of the establishment of ISOs and RTOs. To avoid the confounding effects of electric restructuring, the model is estimated with the full panel data set, and then again without the states that have restructured their electric markets. This estimation shows that electricity prices fall approximately 4.8 % in the first 2 years of an ISO’s operation and that this result is statistically significant. However, this result is dependent on the presence of states that restructured their electricity markets. When these restructured states are removed from the data set the price effects of RTOs become indistinguishable from zero. The paper concludes that rate agreements are the principal source of the observed decrease in prices and that RTOs have not had the desired effect on electricity prices.

Price Effects of Independent Transmission System Operators in the United States Electricity Market

In 1996, the Federal Energy Regulatory Commission sought to “remove impediments to competition in the wholesale bulk power marketplace and to bring more efficient, lower cost power to the Nation’s electricity consumers” through a series of market rules. A product of these rules was the establishment of regional transmission organizations (RTOs) and independent system operators (ISOs) charged with facilitating equal access to the transmission grid for electricity suppliers. Whether these changes in market structure have succeeded in achieving the FERC’s goal to provide “lower cost power to the Nation’s electricity consumers” remains an open question. We utilize a panel data set of the 48 contiguous United States and a treatment effects model in first differences to determine whether there have been changes in delivered electric prices as a result of the establishment of ISOs and RTOs. To avoid the confounding effects of electric restructuring, we have initially estimated the model with the full panel data set, and then again without the states that have restructured their electric markets. By considering only the states that have not restructured their electric markets, we can see whether there have been price effects due to the establishment of RTOs, in the absence of restructuring agreements. We estimate a model of annual changes in electricity prices using 2SLS and show that electricity prices fall approximately 4.9% in the first 2 years of an ISO’s operation and that this result is statistically significant. However, we further show that this result is dependent on the presence of states that restructured their electricity markets and the accompanying rate agreements and temporal subsidies that may have forced prices below their market rates. When these restructured states are removed from the data set the price effects of RTOs become indistinguishable from zero. We conclude that rate agreements are the source of the observed decrease in prices and that RTOs have not had the desired effect on electricity prices.

Impact of Wind Power Development on Transmission Planning at Midwest ISO

The Midwest Independent Transmission System Operator (MISO) has experienced significant amounts of wind power development within the last decade. The MISO footprint spans the majority of the upper Midwest region of the country, from the Dakotas to Indiana and as far east as Michigan. These areas have a rich wind energy resource. States in the MISO footprint have passed laws or set goals that require load serving entities to supply a portion of their load using renewable energy. In order to meet these requirements, significant investments are needed to build the transmission infrastructure necessary to deliver the power from these often remote wind energy resources to the load centers. This paper presents some of the transmission planning related work done at MISO which was largely influenced by current and future needs for increased wind power generation in the footprint. Specifically, topics covered are generator interconnection, long-term planning coordination, and cost-allocation for new transmission lines.

System Operators in the England and Wales Water Industry: Lessons from US and EU Energy Industry Experience

This paper examines the experience of system operators in the electricity and gas industries in the US and the EU and draws lessons for the reform of the England and Wales water supply industry. The main conclusion is that ITSOs (independent transmission system operators) are the most effective type of system operator and provide the largest benefits to consumers. It is argued that regional ITSOs are also likely to be the most appropriate long-run form of system operator for the England and Wales water supply industry, not least because they would best encourage upstream competition and bulk water trading.

Lessons from the history of independent system operators in the energy sector

This paper examines the choice, in electricity and gas systems, between having an independent system operator (ISO) and an independent transmission system operator (ITSO). Both optimise the operation of the system in real time. However ISOs do not own any electricity transmission wires or gas transmission pipes (i.e. electricity and gas systems), while ITSOs do. To examine the choice we will discuss the functions, cost structure, governance and pricing of the ISO, focussing on the US, with regard to controlling the system and operating associated power markets. We outline an ideal model for an electricity system operator and examine the extent to which system operation in the US and the UK conforms to the ideal. Finally, we look at the evolving role of system operators and how their efficiency might be evaluated. We conclude that there is much to learn from ISO experience in operating existing transmission systems.

19 Rules for Transmission: Lessons Learned in Wind Generation [In My View

In 2002 when the midwest independent Transmission System Operator (MISO) started to address wind integration issues, dominate attitudes prevailed that wind was too intermittent to be a major source of power and energy. Wind was forecast to never provide more than 10,000 MW of connected generation in the MISO and SPP areas. Today, MISO alone has 10,000 MW of wind connected to the transmission system. The major driver was that MISO and others adopted the attitude to determine what could be done with wind generation and not what could not be done with wind generation. The lessons learned to date are discussed in this article.

MISO Unlocks Billions in Savings Through the Application of Operations Research for Energy and Ancillary Services Markets

Over the past few years, the Midwest Independent Transmission System Operator, Inc. (MISO) has transformed the electric utility industry in 13 Midwestern US states through the development and implementation of energy and ancillary services markets. MISO uses mixed-integer programming to determine when each power plant should be on or off. Operations research methods set energy output levels and establish the prices at which energy trades. These new markets increased the efficiency of the existing electric infrastructure (power plants and transmission lines) in the Midwest, improved the reliability of the grid, and reduced the need for future infrastructure investments. These advances enabled the MISO region to realize between $2.1 billion and $3.0 billion in cumulative savings from 2007 through 2010. We expect additional savings of $6.1 billion to $8.1 billion through 2020.

Voltage Coordination via Communication in Large-Scale Multi-Area Power Systems. Part I: Principal

This two-part paper deals with the coordination of the control actions in a network of many interacting components, where each component is controlled by independent control agents. As a case study we consider voltage control in large electric power systems, where ever-increasing pressures from the liberalization and globalization of the electricity market has led to partitioning the power system into multiple areas each operated by an independent Transmission System Operator (TSO). Coordination of local control actions taken by those TSOs is a very challenging problem as poorly coordinated operation of TSOs may endanger the power system security by increasing the risk of blackouts. This coordination problem involves many other issues such as communication, abstraction and last but not least optimization. This first part of the paper is devoted to the principals of the coordination control, addressing some of those issues using as a case study the problem of coordination control for avoiding voltage collapse in large-scale multi-area power systems.