303 research outputs found
Joustotuotteet monenkeskisillä sähkömarkkinoilla
Power grids, electrical systems and liberalized zonal electricity markets are in due for major recasting as the ongoing energy transition impacts the electricity sector profoundly.This will mean new kinds of market behavior in liberalized and regulated electricity markets and increased challenges for TSOs to maintain power balance at system-level. Also, inadequacies in network capacity and flexible asset availability impact at local level. Congestions, voltage deviations and grid outages impact both TSOs and DSOs locally and the mitigation of these situations requires new types of multilateral coordination. In addition to more transmission and distribution grid capacity, future electrical systems need resilient flexible resources and intelligent control mechanisms. This thesis examines market-based control by using flexibility products. The envisioned flexibility products are expected to be implementable in the Baltic Sea area electricity markets during the regulatory period of Finnish electricity network companies beginning in 2024.
Thesis includes a literature review and a qualitative empirical research consisting of industry consultation. First, the literature study examines existing products traded on future European electricity markets and other mechanisms that control networks and network connected assets. Secondly, it examines emerging flexibility products that can provide local flexibility services which the existing product structure is not covering.
Industry consultation includes Finnish expert views regarding different aspects of flexibility needs,flexibility markets and opinions on the emerging flexibility products. Interviewees found the concepts of flexibility markets and products new and complex. Most of the interviewees had not experienced serious technical flexibility issues at local level in Finnish electrical networks but agreed that local flexibility challenges would be a reality in Finland within next five years. Majority of interviewees saw new enabling technologies and market-based trading of local flexibility worth considering. They had different local needs for flexibility products, if trading could be done cost-efficiently and market design would be supportive for both flexibility buyers and sellers. Outage management and voltage support with flexibility were identified as the most urgent local needs and congestion management was seen less important.
According to the findings, numerous although contradictory flexibility product alternatives can solve different flexibility needs. It was concluded that market design should go forward with the development of three options: locational intraday products, locational balancing products and competitive bilateral flexibility contracts. The results show, that these recommended products are modifications of existing products. All three preferred options should be enabled due to different reasons and these options are not mutually exclusive. The compatibility of flexibility products with existing products and operational processes must be ensured, especially considering reconciliation of flexibility markets and a reactive balancing model of TSOs. Development of flexibility products should start immediately with incremental experimentation with cooperation of all network users and operators.Meneillään oleva energiamurros aiheuttaa merkittäviä muutoksia sähköverkkoihin ja-markkinoihin. Tämä johtaa uudenlaiseen käyttäytymiseen vapautetuilla ja säännellyillä sähkömarkkinoilla sekä kantaverkkoyhtiöiden lisääntyviin haasteisiin ylläpitää järjestelmätason tehotasapainoa. Myös alueelliset haasteet lisääntyvät riittämättömän verkkokapasiteetin tai joustavien resurssien puuttuessa. Paikalliset ylikuormitukset, jännite- ja loistehopoikkeamat sekä käyttökatkot voivat vaikuttaa useisiin siirto- ja jakeluverkkoyhtiöihin, jolloin ratkaisut vaativat monenkeskistä koordinointia. Tulevaisuuden sähköjärjestelmät vaativat lisää siirto- ja jakeluverkkokapasiteettia, joustavia resursseja ja älykkäitä ohjausmekanismeja. Tässä diplomityössä tutkitaan markkinaehtoisiin joustotuotteisiin perustuvia ohjausmekanismeja. Suunniteltujen joustotuotteiden on tarkoitus olla käytettävissä 2024 alkavalla suomalaisten sähköverkkoyhtiöiden sääntelykaudella Itämeren alueen sähkömarkkinoilla.
Tämä diplomityö sisältää kirjallisuuskatsauksen ja empiirisen tutkimuksen, joka koostuu sähköalan asiantuntijoiden laadullisesta konsultaatiosta. Työssä tarkastellaan nykyisten sähkömarkkinoiden tuotteita, joilla verkkoja ja verkkoon kytkettyjä resursseja hallitaan. Lisäksi työ tutkii kehittyviä joustotuotteita, jotka voivat tarjota paikallisia joustopalveluita, joita nykyiset tuotteet eivät kata. Konsultaatio sisällyttää alan näkemyksiä jouston tarpeista, joustomarkkinoista ja kehittyvistä joustotuotteista tutkimukseen.
Haastateltavat kokivat joustomarkkinoiden ja -tuotteiden käsitteet uusiksi ja monimutkaisiksi. Suurin osa haastatelluista ei ollut todennut suomalaisissa sähköverkoissa alueellisesti vakavia haasteita, mutta arvioivat paikallisten joustavuushaasteiden yleistyvän seuraavan viiden vuoden aikana. Merkittävä osa asiantuntijoista arvioi uudet teknologiaratkaisut ja markkinalähtöisen joustokaupankäynnin harkinnan arvoiseksi, mikäli kaupankäynti on kustannustehokasta ja kannattavaa sekä joustavuuden ostajille että myyjille. Keskeyttämätön sähkönsyöttö ja loistehon hallinta tunnistettiin kiireellisiksi paikallisiksi tarpeiksi ja siirtojenhallintaa pidettiin vähemmän kiireellisenä tarpeena.
Työn mukaan lukuisat ja keskenään ristiriitaiset joustotuotevaihtoehdot voivat ratkaista erilaisia joustotarpeita. Ensisijaisesti tulisi keskittyä kolmen kategorian tuotteiden kehittämiseen: sijainnilliset päivänsisäisen markkinan tuotteet, sijainnilliset säätösähkömarkkinan tuotteet ja kilpailutetut kahdenväliset joustosopimukset. Tuloksista voidaan nähdä, että kaikki kolme vaihtoehtoa ovat olemassa olevien tuotteiden muunnoksia. Tuotteet ovat otettavissa käyttöön eri syistä, ja vaihtoehdot eivät ole toisiaan poissulkevia. Joustotuotteiden yhteensopivuus olemassa olevien tuotteiden ja toimintaprosessien kanssa on taattava, erityisesti yhteensovittaminen kantaverkkojen reaktiivisen säätötavan kanssa on varmistettava. Joustomarkkinoiden jatkokehittäminen tulisi aloittaa välittämättömästi kokeiluilla ja verkonhaltijoiden ja -käyttäjien yhteistyöllä
Utilization of Electric Prosumer Flexibility Incentivized by Spot and Balancing Markets
The use of energy flexibility to balance electricity demand and supply is becoming increasingly important due to the growing share of fluctuating energy sources. Electric flexibility regarding time or magnitude of consumption can be offered in the form of different products on electricity spot and balancing power markets. In the wake of the energy transition and because of new possibilities provided by digitalization, the decision intervals on these markets are becoming shorter and the controllability of electricity consumption and generation more small-scale. This evolution opens up new chances for formerly passive energy consumers.
This thesis shows how electric flexibility can be monetized using the application example of commercial sites. These are often multimodal energy systems coupling electricity, heat, and gas, and thus deliver high flexibility potential. To leverage this potential, a comprehensive picture of demand-side flexibilization is provided and used to propose an energy management system and optimization for cost-optimized device schedules. The cost-optimization considers two simultaneous incentives: variable day-ahead spot market prices and revenues for offering possible schedule adjustments to the automatic Frequency Restoration Reserve (aFRR) balancing market.
To solve the formulated optimization problem, a genetic algorithm is presented, tailored to the specific needs of consumers. In addition to addressing the trade-off between the two competing markets, the algorithm inherently considers the uncertain activation of aFRR bids and related catch-up effects. An analysis of the activation behavior of aFRR balancing market bids, based on a developed ex-post simulation, forms an important decision basis for the optimization. Finally, a simulation study concentrating on battery energy storage systems and combined heat and power plants on the consumer side enables the quantitative discussion of the optimization potential.
The results show that consumers considering both markets simultaneously can achieve cost benefits that are up to multiples of those for pure day-ahead price optimization, despite the stochastic nature of aFRR balancing power activations. In conclusion, this thesis enables formerly passive electricity consumers to assume the role of alternative balancing service providers, hence contributing to the economic and reliable operation of power grids characterized by a high share of renewable energy sources
Decision-making under uncertainty in short-term electricity markets
In the course of the energy transition, the share of electricity generation from renewable energy sources in Germany has increased significantly in recent years and will continue to rise. Particularly fluctuating renewables like wind and solar bring more uncertainty and volatility to the electricity system. As markets determine the unit commitment in systems with self-dispatch, many changes have been made to the design of electricity markets to meet the new challenges. Thereby, a trend towards real-time can be observed. Short-term electricity markets are becoming more important and are seen as suitable for efficient resource allocation. Therefore, it is inevitable for market participants to develop strategies for trading electricity and flexibility in these segments.
The research conducted in this thesis aims to enable better decisions in short-term electricity markets. To achieve this, a multitude of quantitative methods is developed and applied: (a) forecasting methods based on econometrics and machine learning, (b) methods for stochastic modeling of time series, (c) scenario generation and reduction methods, as well as (d) stochastic programming methods. Most significantly, two- and three-stage stochastic optimization problems are formulated to derive optimal trading decisions and unit commitment in the context of short-term electricity markets. The problem formulations adequately account for the sequential structure, the characteristics and the technical requirements of the different market segments, as well as the available information regarding uncertain generation volumes and prices. The thesis contains three case studies focusing on the German electricity markets.
Results confirm that, based on appropriate representations of the uncertainty of market prices and renewable generation, the optimization approaches allow to derive sound trading strategies across multiple revenue streams, with which market participants can effectively balance the inevitable trade-off between expected profit and associated risk. By considering coherent risk metrics and flexibly adaptable risk attitudes, the trading strategies allow to substantially reduce risk with only moderate expected profit losses. These results are significant, as improving trading decisions that determine the allocation of resources in the electricity system plays a key role in coping with the uncertainty from renewables and hence contributes to the ultimate success of the energy transition
TSO-DSO-Customer coordination for purchasing flexibility system services: Challenges and lessons learned from a demonstration in Sweden
This paper presents a real-word implementation of a TSO-DSO-customer coordination framework for the use of flexibility to support system operation. First, we describe the general requirements for TSO-DSO-customer coordination, including potential coordination schemes, actors and roles and the required architecture. Then, we particularise those general requirements for a real-world demonstration in Sweden, aiming to avoid congestions in the grid during the high-demand winter season. In the light of current congestion management rules and existing markets in Sweden, we describe an integration path to newly defined flexibility markets in support of new tools that we developed for this application. The results show that the use of flexibility can reduce the congestion costs while enhancing the secure operation of the system. Additionally, we discuss challenges and lessons learned from the demonstration, including the importance of the engagement between stakeholders, the role of availability remuneration, and the paramount importance of defining appropriate technical requirements and market timings.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement nº 824414
A data-driven approach using deep learning time series prediction for forecasting power system variables
This study investigates the performance of ‘Group Method of Data Handling’ type neural network algorithm in short-term time series prediction of the renewable energy and grid-balancing variables, such as the Net Regulation Volume (NRV) and System Imbalance (SI). The proposed method is compared with a Multi-layer Perceptron (MLP) neural network which is known as a universal approximator. Empirical validation results show that the GMDH performance is more accurate in compression with the most recent forecast which is provided by ELIA (Belgian transmission system operator). This study aims to practice the applicability of the polynomial GMDH-type neural network algorithm in time series prediction under a wide range of complexity and uncertainty related to the environment and electricity market
Operational concepts for grid services using electric vehicles
The European electricity grid is subject to increasing stresses due to increasing share of volatile renewable energy technologies. These technologies, coupled with higher volatility in demand, pose challenges to the stability and security of the European grid, erstwhile dominated by large and relatively reliable conventional generation. As the contribution of wind and photovoltaic generation increases in the energy mix, it demands an assessment of the corresponding risk to frequency stability and possible preventive measures. Uncontrolled charging of the increasing number of electric vehicles in Germany also demands a thorough investigation of methods for their integration in the electricity grid to not only improve grid frequency stability but also to provide secondary benefits to electric vehicle users. This work analyzes the load frequency control systems for their suitability for integration of electric vehicles and the impact of increase in volatile renewable energy on frequency stability for the case of Germany, showing a significant increase in reserve requirements. Evaluation of alternative approaches to load frequency control on the basis of infrastructure requirements shows that introduction of an aggregator of distributed energy resources can significantly reduce the overall infrastructure requirements for grid operators. The operational concepts herein proposed are evaluated using several case studies for optimizing the use of electric vehicles for grid flexibility services by taking into account the usage requirements of the vehicle owner and supply requirements of grid services.Das europäische Stromnetz ist aufgrund des steigenden Anteils volatiler erneuerbare Energiequellen einer zunehmenden Belastung ausgesetzt. Diese Technologien, in Ver-bindung mit einer höheren Volatilität der Nachfrage, stellen eine Herausforderung für die Stabilität und Sicherheit des europäischen Netzes dar, das früher von einer zentrali-sierteren Erzeugung in großen und relativ zuverlässigen konventionellen Kraftwerken geprägt war. Mit zunehmendem Beitrag der Wind- und Photovoltaikerzeugung am Energiemix ist eine Bewertung des Risikos für die Frequenzstabilität und mögliche Prä-ventivmaßnahmen erforderlich. Die ungesteuerte Aufladung der zunehmenden Anzahl von Elektrofahrzeugen in Deutschland erfordert auch eine gründliche Untersuchung der Methoden für ihre Integration in das Stromnetz, um nicht nur die Stabilität der Strom-netzfrequenz zu verbessern, sondern auch einen sekundären Nutzen für die Elektrofahr-zeug-Nutzer zu erzielen. Diese Arbeit analysiert die Lastfrequenzregelungssysteme auf ihre Eignung zur Integration von Elektrofahrzeugen ins Stromnetz sowie die Auswir-kungen der Erhöhung des Anteils von volatilen erneuerbaren Energien auf die Frequenz-stabilität in Deutschland, und zeigt einen deutlichen Anstieg der Anforderungen an Re-servekapazität. Die Bewertung alternativer Ansätze zur Lastfrequenzsteuerung auf der Grundlage von Infrastrukturanforderungen zeigt, dass die Einführung eines verteilten Energieressourcen Aggregators den gesamten Infrastrukturbedarf der Netzbetreiber deutlich reduzieren kann. Die hierin vorgeschlagenen Betriebskonzepte werden anhand mehrerer Fallstudien zur Optimierung des Einsatzes von Elektrofahrzeugen für Flexibili-tätsdienstleistungen im Stromnetz unter Berücksichtigung der Anforderungen der Fahr-zeughalter und des Versorgungsbedarfs von Netzdiensten bewertetThis thesis deals with the challenges to frequency stability in the European electricity grid posed by the increasing share of renewable energy resources and electric vehicles. It evaluates European load frequency control systems for their suitability for integration of electric vehicles and the impact of increase in photovoltaic and wind power on frequency stability for the case of Germany, demonstrating a consequent significant increase in frequency control reserve requirements. Evaluation of alternative approaches to load frequency control shows that introduction of an aggregator of distributed energy resources can also significantly reduce the overall infrastructure requirements for grid operators. The operational concepts herein proposed are evaluated using several case studies for optimizing the use of electric vehicles for grid flexibility services by taking into account the user behavior of vehicle owners and supply requirements of these grid services
ICT architectures for TSO-DSO coordination and data exchange: a European perspective
The coordination between system operators is a key element for the decarbonization of the power system. Over the past few years, many EU-funded research projects have addressed the challenges of Transmission System Operators (TSO) and Distribution System Operators (DSO) coordination by implementing different data exchange architectures. This paper presents a review of the ICT architectures implemented for the main coordination schemes demonstrated in such projects. The main used technologies are analyzed, considering the type of data exchanged and the communication link. Finally, the paper presents the different gaps and challenges on TSO-DSO coordination related to ICT architectures that must still be faced, paying especial attention to the expected contribution of the EU-funded OneNet project on this topic. IEEECoordiNet H202
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