Antje Orths

Energinet

In an effort to protect the environment despite the projected development of the electrical power system, the European community is focusing on a significant increase in the installed wind power capacity up to the level of 300 GW by the year 2030 throughout Europe. Most of the planned installations - about 150 GW - are going to be realized in the o...

In this Ph.D. dissertation a new method is presented on how to solve the expansion planning of distribution power networks which is particularly suitable for a liberalised energy market. First, the changes in the planning process due to the liberalisation are analysed. Thus it appears that due to the implementation of the energy market, on the one...

The amount of wind power in the world is increasing quickly. The background for this development is improved technology, decreased costs for the units, and increased concern regarding environmental problems of competing technologies such as fossil fuels. The amount of wind power is not spread equally over the world, so in some areas, there is compa...

With declining technology costs, high resource quality, and the increasing scale of turbines and wind farms, offshore wind (OSW) has become the world’s fastest growing renewable generation technology.

For those of us working during the past couple of decades to integrate wind, and then solar, storage, and now distributed energy resources, we have witnessed a tremendous shift in the power industry. There once was a utility “rule of thumb” that you could not integrate more than 10% wind into a power system. Studies were undertaken to show that sys...

As the share of VRE (variable renewable energy) has grown rapidly, curtailment issues have arisen worldwide. This paper evaluates and compares curtailment situations in selected countries using an objective and quantitative evaluation tool named the “C-E map” (curtailment-energy share map). The C-E map is a correlation map between curtailment ratio...

Numerous countries, states, utilities, cities, and corporations have adopted 100% clean electricity goals to slow climate change. Typical goals are to achieve 100% clean electricity by 2035 and 100% clean energy by 2050 while maintaining an affordable, reliable energy system. This article explores the role of high-voltage transmission as an enabler...

Variable Renewable Energy (VRE), i.e., wind and solar photovoltaics (PVs), is being installed in rapidly increasing amounts around the world. Growth in VRE is being spurred by ambitious zero-carbon targets set by countries and individual states across the globe. The European Union approved a carbon neutrality target for 2050 in 2019. Japan’s newly...

This report summarises findings on wind integration from the 17 countries or sponsors participating in the International Energy Agency Wind Technology Collaboration Programme (IEA Wind TCP) Task 25 from 2006–2020. Both real experience and studies are reported. Many wind integration studies incorporate solar energy, and most of the results discussed...

The demand for low carbon energy calls for close to 100% renewable power systems, with decarbonization of other energy sectors adding to the anticipated paradigm shift. Rising levels of variable inverter-based renewable energy sources (VIBRES) are prompting questions about how such systems will be planned and operated when variable renewable genera...

Multicarrier energy systems (MCESs) are characterized by strong coordination in operation and planning across multiple energy vectors and/or sectors to deliver reliable, cost-effective energy services to end users/customers with minimal impact on the environment. They have efficiency and flexibility benefits and are deployed in large and small scal...

Rapidly increasing levels of variable inverter‐based renewable energy sources are quickly changing electric power systems and prompting questions about how the systems will be operated when renewable generation becomes the dominant technologies. In this article, we review the status of this shifting paradigm in power systems throughout the world. W...

Energy systems integration, or sector coupling, has several drivers that span climate impact mitigation and economics to social and regulatory considerations. A key question is what is sector coupling, and how does it impact the flexibility of the energy system? Here, the energy system includes several sectors—electricity, gas, heat, and transporta...

In order to effectively utilize hydro production flexibility, a sufficient amount of transmission capacity has to be available between the hydro‐dominated part of the system and the part that requires operational flexibility. This chapter starts with a rough categorization of “base” hydropower flexibility, investigating the types of hydropower plan...

This chapter provides an overview of major transmission planning activities related to wind integration studies in the United States and Europe. Transmission planning for energy resources is different from planning for capacity resources. Those differences are explained and illustrated with examples from several regions of the United States and Eur...

This report summarises recent findings on wind integration from the 17 countries and Wind Europe participating in the International Energy Agency (IEA) Wind collaboration research Task 25 from 2015–2017. Both real experiences and studies are reported. Many wind integration studies incorporate solar energy, and most of the results discussed here are...

Many individual wind and solar integration studies have been conducted in the past. The integration studies have evolved towards looking at the integration of wind and solar at the same time. Integration studies typically simulate a future power system with wind and solar contributions (share or penetration) varying from 5% to more than 50% of annu...

Electric infrastructure worldwide has evolved significantly over the last decade, as nations increase the renewable share of their generation portfolio and build transmission to move energy from the resources to the load centers. Since 2007, the United States has increased its percentage of electric energy generated from wind and solar from lower t...

Greater penetrations of variable renewable generation on some electric grids have resulted in increased levels of curtailment in recent years. Studies of renewable energy grid integration have found that curtailment levels may grow as the penetration of wind and solar energy generation increases. This paper reviews international experience with cur...

The Danish political energy and climate targets fixed in the RES directive require Denmark to reach a 30% RES share of its total energy consumption in 2020. Besides, Danish national targets aim at windpower production to correspond to 50% of domestic gross electricity consumption (status in 2015: 42%). For 2050, the political target is to be free o...

Hydro power is one of the most flexible sources of electricity production. Power systems with considerable amounts of flexible hydro power potentially offer easier integration of variable generation, e.g., wind and solar. However, there exist operational constraints to ensure mid-/long-term security of supply while keeping river flows and reservoir...

Hydro power is one of the most flexible sources of electricity production. Power systems with considerable amounts of flexible hydro power potentially offer easier integration of variable generation, e.g. wind and solar. However, there exist operational constraints to ensure mid/long term security of supply while keeping river flows and reservoirs...

In recent months, energy policy in the ?European Union (EU) has started to focus on the concrete actions required to ensure the realization of a functioning internal energy market in the context of high levels of renewable energy in the post-2020 period. The most important developments include the agreement by the European Council on energy and cli...

Variable renewable generation is increasing in penetration in modern power systems, leading to higher variability in the supply and price of electricity as well as lower average spot prices. This raises new challenges, particularly in ensuring sufficient capacity and flexibility from conventional technologies. As the fixed costs and lifetimes of el...

By 2020, it is expected that about 42 GW of offshore wind capacity will be built in European waters and 30 GW off the shore of China. According to the U.S. Department of Energy's National Offshore Wind Strategy, estimates for the United States are for approximately 10 GW of offshore capacity by then. This article gives an overview of current develo...

This paper evaluates various aspects of flexibility in power systems worldwide within the multi-country study framework of IEA Wind Task 25: which grid components/ actions have been favoured for enhancing suitable flexibility in different areas/countries/regions, and how have TSOs/ISOs/ utilities intended, and will intend, to manage variable genera...

High penetrations of wind and solar generation on power systems are resulting in increasing curtailment. Wind and solar integration studies also predict increased curtailment as penetration levels grow. This paper examines experiences with curtailment on the bulk power system in countries around the world. It discusses how much curtailment is occur...

IEA WIND R&D Task 25 on “Design and Operation of Power Systems with Large Amounts of Wind Power” collects and shares information on wind generation impacts on power systems, with analyses and guidelines on methodologies. This paper sumarizes the main results from the report published on January 2013 describing the experience of wind integration as...

This Expert Group Report provides recommendations based on more than 8 years of work within International Energy Agency (IEA) Wind Task 25 Design and Operation of Power Systems with Large Amounts of Wind Power. The report is issued as an IEA Wind Recommended Practices document to provide research institutes, consultants, and system operators with t...

High penetrations of wind and solar generation on power systems are resulting in increasing curtailment. Wind and solar integration studies also predict increased curtailment as penetration levels grow. This paper examines experiences with curtailment on the bulk power system in countries around the world. It discusses how much curtailment is occur...

The International Energy Agency Implementing Agreement for Co-operation in the Research, Development and Deployment of Wind Energy Systems (IEA Wind) is a vehicle for member countries to exchange information on the planning and execution of national, large-scale wind system projects and to undertake co-operative research and development projects ca...

This paper analyzes selected issues concerning operational strategies for multiterminal dc offshore power systems (OPSs). In the first section, the main challenges regarding the operation of such an OPS are discussed, and a proposal is given for a new observer-based management system (OBMS) used for operation coordination using references from the...

This paper provides an overview of major transmission planning activities related to wind integration studies in the United States and Europe. Transmission planning for energy resources is different from planning for capacity resources. Those differences are explained, and illustrated with examples from several regions of the United States and Euro...

The North Seas Countries' Offshore Grid initiative (NSCOGI) was formed as the responsible body to investigate barriers and propose solutions to the 10 countries' energy ministers, in order to enhance the topic to a next stage. The paper describes investigations and their results comparing two different offshore grid design concepts. The concepts ar...

This paper deals with reliability assessment issues for a DC Offshore Power System. In the first step a methodology for reliability evaluation of an offshore power system is characterized. For this purpose new reliability indices are introduced in order to take the specific character of the offshore grid into account. Then, using a Monte Carlo simu...

In December 2010 the North Seas Countries' Offshore Grid initiative (NSCOGI) was formed as the responsible body to investigate barriers and propose two years later solutions to the 10 countries' energy ministers, to facilitate a decision on the way forward. The paper describes investigations and results concerning two different offshore grid design...

In Europe, a large amount of offshore wind power is expected to be built. Today, there is about 3,5 GW of offshore wind power capacity installed, and potential has been identified to an increase to 150 GW on-and offshore wind power by 2030. About half of European offshore wind is expected to be built in the North Seas, about 60-80 GW by 2030. Some...

In this paper a new parameter - Observability Level Assessment (OLA) - is introduced and defined. The parameter can be used to determine the observability of an electrical network. The defined five levels of the OLA index provide statements if the Phasor Measurement Units (PMU) have been placed in a sufficient number and if optimal measuring sites...

THE European Union has enacted ambitious binding targets concerning the implementation of renewable energy sources into the present energy systems until the year 2020, with large share allocated to wind energy. Although no common European energy policy is enacted for the period after 2020, TSOs, manufacturers, regulators and research institutions a...

This paper uses a simulation to investigate the feasibility of applying low frequency AC (LFAC) transmission technology to connect large offshore wind farms to the onshore power system. Compared to the conventional AC transmission system with a power frequency of 50 or 60 Hz, the LFAC system can transfer more power through longer distance and with...

Smart transmission seems to become the next instance of the smart grid vision. However, most of the innovative tech-no-logies, which have been foreseen for a smart distribution grid, are not totally new into the transmission system operation environment. If it comes to large scale wind power integration in the north of Europe, as well as bulk solar...

The Danish power system is known for being the first system with both, a very fast growth of wind energy providing today a significant share of electricity consumption. The massive expansion of wind power is the result of targeted political efforts by e.g. introducing extensive public subsidising schemes. Simultaneously to the increase of wind powe...

The electric system within an offshore wind power plant and its connection to the main power system pose new challenges to the experts. The best way of interconnecting the wind turbines inside a wind farm has to be found, fulfilling both, redundancy requirements without compromising economic feasibility. The best choice between technologies (HVAC,...

TTHE POWER SYSTEMS IN DENMARK, PORTUGAL, Spain, Ireland, and Germany have some of the highest wind penetrations in the world, as shown in Table 1. The management of the different power systems to date, with increasing amounts of wind energy, has been successful. There have been no reported incidents in which wind has directly or indirectly been a m...

In this session the following subjects will be treated related to this topic and with focus on PQ: a.) voltage dips and harmonics, b.) resonances and mitigation measures, c.) PV systems and asymmetric infeeds, d.) ancillary services of PE converters and storage systems, e.) data collection and smart metering, f.) electrical vehicles as loads, g.) d...

This work aims to design the optimal energy storage capacity for Virtual Power Plant (VPP) architecture with a high degree of penetration of Renewable Energy Sources (RES). In order to achieve this target a multi-criteria analysis was performed. Economical issues as well as the reliability of the VPP are the main criteria taken into consideration....

There are dozens of studies made and ongoing related to wind integration. However, the results are not easy to compare. IEA WIND R&D Task 25 on ‘Design and Operation of Power Systems with Large Amounts of Wind Power’ collects and shares information on wind generation impacts on power systems, with analyses and guidelines on methodologies. In the st...

The main task of a wind farm is to get as much energy as possible from the minimal number of wind turbines and with a minimal space between the turbines due to the economy of land in onshore and connections costs in offshore. However, minimization of the distance between single wind turbines within a wind farm causes an increase of the so called wa...

Historically, both transmission and operational planning studies and criteria were for the most part deterministic. In today’s new market paradigm of separated generation, transmission and distribution entities most electric utilities still employ these traditional deterministic approaches for planning studies. As a result of the new market paradig...

This paper aims to give an overview on main PQ development in Europe. It focuses basically on recent legislative, regulatory, standardization, voltage quality monitoring and education initiatives summarizing the latest outcomes.

The European Union has enacted ambitious targets concerning the implementation of renewable energy sources into the present energy systems. These targets are binding and have stepwise to be fulfilled until the year 2020.

The power systems in Denmark, Spain, Ireland, and New Zealand have some of the highest wind penetrations in the world. The management of the different power systems to date, with increasing amounts of wind energy, has been successful. There have been no incidents in which the wind has directly or indirectly been a major factor causing operational p...

The Danish power system is characterized by a high share of wind power production as well as production from local scale combined heat and power units, both called dispersed generation (DG). Today, with respect to market terms, these units work together as virtual power plants. Currently also the technical aspects are further developed. According t...

There are already several power systems coping with large amounts of wind power. Hi h penetration of wind power has impacts that have to be manage through proper plant interconnection, integration, transmission planning, and system and market operations. This report is a summary of case studies addressing concerns about the impact of wind power.s v...

Electricity is the most flexible form of energy accessible to humans. It can be transported over long distances, and transformed into almost any other kind of energy like heat, radiation or kinetic energy. Electrical engineering is very closely coupled especially to mechanical engineering but also to many other fields of engineering. This chapter w...

The Danish system is characterized by a high share of wind power production as well as production from combined heat and power units, both called dispersed generation (DG). The actual governmental plans for the implementation of additional 3,000 MW of wind power capacity until the year 2025 lead to a future situation where the installed wind power...

The existing software for the simulation of power system operation was mainly developed and optimized for the analysis of conventional systems that are characterized by a low number of large, central synchronous generators. New forms of power generation, like wind turbines, that are characterized by a high number of small units can not be analyzed...

In this situation the operation and management of power systems with high shares of wind power require extended analyses. This panel fits very well with the objectives of IEA annex 25 on design and operation of power systems with large amounts of wind power.

New challenges to the power system have been evoked by the worldwide shortage of primary energy sources and have resulted especially in a high penetration of renewable energy generation in the system. However, the high reliability of customer supply must be maintained in the future while the structure and the tasks of the power networks will change...

Die elektrischen Energiesysteme stehen heute im Zentrum der gesellschaftlichen Debatte. Seitdem vor etwa 120 Jahren der Wechselstrom - basierend auf einem Tesla Patent - eingeführt wurde, hat sich diese Form der Energieerzeugung und Übertragung zu einem der wichtigsten Versorgungssysteme der modernen Gesellschaft entwickelt. Die elektrischen NetzeE...

High penetration of wind power has impacts that have to be managed through proper plant interconnection, integration, transmission planning, and system and market operations. This report is a summary of case studies addressing concerns about the impact of wind power’s variability and uncertainty on power system reliability and costs. The case studi...

The Danish power system is characterized by a high share of dispersed generation (DG) and wind power plants. Today about 24 % of the electricity consumption is produced by wind turbines and about 19 % by combined heat and power units (CHP). The paper shows, how the Danish transmission system operator (TSO), Energinet.dk, handles the tasks of provid...

Hannele Holttinen, Peter Meibom, Antje Orths, Frans Van Hulle, Cornel Ensslin, Lutz Hofmann,

The share of the dispersed energy production is supposed to increase in the next years in many countries up to 30%. Wind, PV, CHP, microturbines, fuel cells and also different kinds of energy storages are expected to be the future decentralised generation units. These units supply electrical energy at the low and medium voltage level which changes...

Since the early 80s a huge amount of dispersed generation (DG) has been implemented into the Danish power systems. Today the Danish system has a share of 18.5% electricity consumption produced by wind turbines and 26.5% produced by combined heat and power units (CHP), of which the biggest part is installed in the western part of Denmark. The paper...

The widespread use of distributed generation (DG) relies on methods and techniques aimed at facilitating the network integration of DG. In this context a methodology for the evaluation of the quality and relative merits of these methods and techniques is missing. CIGRE Task Force C6.04.02, which is affiliated with CIGRE Study Committee C6, has addr...

An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. The task 'Design and Operation of Power Systems with Large Amounts of Wind Power' will analyse existing case studies from different power systems. There are a multitude of studies made and ongoi...

The increase of wind energy development is reflected in the specific requirements for the connection of large wind farms to the transmission system including requirements for the control and interaction between the wind farm and the power system. It is necessary to investigate the power system stability and control with regard to wind power generat...

An increase of dispersed energy resources (DER) in the power system is expected within the next decade. Computations are necessary to find out the best proportion of dispersed generation to conventional power generation. This paper presents results of long-term-interval network simulations considering suitable models of DER. Problems of voltage con...

The conditions for power network planning in Germany have changed due to the liberalization of the energy market and the legal promotion of dispersed energy resources (DER). To meet these new requirements, an effective multi-criteria optimization method based on game theory has been developed, describing the technical-economical dependencies and th...

In the paper a multi-criteria optimization method useful in the deregulated energy system for power network planning is presented. The power network planning process is modeled in mathematical form by game theoretical methods. The planning criteria are modeled as players in the game algorithms. Using this, the optimal power network scenario can be...

The liberalization of the electric energy market changes the tasks of power network planning as well as of network operation into multi-criteria optimization problems. In this paper two different Pareto-based optimization techniques are presented, which are suitable for this kind of problems.

Several concepts of offshore power systems have recently been discussed. The further realisation of these systems requires comprehensive computation studies to find optimal technical network solutions. Generally, the AC technique will be applied for electrical energy transmission. However, the current studies show that in practice two concepts will...