OFFSHORE WIND ENERGY RENEWABLE BULK POWER BUT NO TRANSMISSION? 5 TH CONFERENCE ON APPLIED INFRASTRUCTURE RESEARCH

Transcription

1 OFFSHORE WIND ENERGY RENEWABLE BULK POWER BUT NO TRANSMISSION? 5 TH CONFERENCE ON APPLIED INFRASTRUCTURE RESEARCH SUSTAINABLE EUROPEAN INFRASTRUCTURE FINANCING UNDER THE CONDITIONS OF COMPETITION, ENVIRONMENTAL CONCERNS AND EU ENLARGEMENT 6-7OCTOBER 2006 PRESENTED BY: BARD ENGINEERING, EMDEN BARD ENGINEERING GMBH AM FREIHAFEN 1 D Emden GERMANY TEL (+49) heiko.ross@bard-engineering.de

2 SUMMARY Developing Europe s potential for using renewable energy will contribute to security of energy supply, reduce fuel imports and dependency, reduce green house gas emissions, improve environmental protection, decouple economic growth from resource use, create jobs, and consolidate efforts towards a knowledge based society. This view offered by the EU Commission in (COM (2004) 366) is one of the major drivers in the German offshore wind business. Facing issues like water depths of more than 40 m for the installation of platforms of wind turbines and substation equipment, the development of grid connections of wind power plants of more than 400 MW and distances to coast of more than 100 km represents an important part of the engineering work. The grid connection for the German offshore wind power plants will follow phases. These phases are: Phase 1: Feasibility of large Offshore Wind Power plants German offshore wind power plants with rated power of more than 400 MW are a technical leap forward compared to existing projects.. For this first phase the proof of feasibility regarding large scale turbines and grid connection are the objectives. Phase 2: Grid structures providing safe and economical grid access, supporting the environment by using minimum space In the Exclusive Economical Zone (EEZ) of German clusters of offshore wind power plants at close distance can be connected by using AC cables to provide redundancy. For bulk power transport of more than MW HVDC connections provide safe and environmental friendly grid connection solutions small offshore-grids will be established. Phase 3: Offshore Grid structures, connecting Offshore Wind Power plants Small Offshore grids can be connected to an offshore grid. This grid can help to avoid bottlenecks onshore (for example Denmark Germany, Crossing Elbe River, Netherlands Germany) and will be beneficial for the energy exchange between Offshore Wind Power plants with respect to different wind situations. A European offshore grid will help to transport bulk power of offshore wind electricity. Offshore wind energy will be competitive in the next years. The installation of grid structures will take years and billions of Euros. Even with the first large offshore wind power plants (phase 1) the grid connection shall fit in an overall strategy. With the installation of a west east offshore grid and supporting regulations for costs for balance power can be decreased. By establishing an European Grid September 18, Copyright 2004

3 Control strategy and the west-east-connection the predictability of offshore wind farms shall improve. This will help to reduce costs for reserve power. The kick-off for a feasibility study for offshore grid structures supporting offshore wind power plants is of high time. BARD Engineering Heiko Roß Managing Director September 18, Copyright 2004

4 TABLE OF CONTENTS Summary Energy Supply in Europe Current Status and Outlook Time Schedule Offshore Wind Scenaros Status of Offshore Wind Turbines More than 400 MW Rated Power Phase 1 Until Feasibility Phase 2 Until 2015 Local clusters Phase 3 Starting from 2015 New EHV-grid-Structures Assessment of economical Situation of an Offshore Grid Meteorological Effects of offshore wind power plants Approvals for EHV-grids Advantage for Sub- Sea-Cables EHV-Offshore-Grid Contribution to an open energy market Next Steps...17 September 18, Copyright 2004

5 1 ENERGY SUPPLY IN EUROPE CURRENT STATUS AND OUTLOOK Electric power consumption in Europe will maintain on a high level. Increase of consumption is expected by growth rates between % (EWI/ Prognos 2005, BMWi 2005 ). The scenario of energy consumption worldwide expected a rate of increase of % (IEA 2004, WETO 2003). Regarding this scenario, the value of renewable energies like wind, biomass, biogas and others becomes more and more important, not just for avoiding CO 2 -emissions. Today, the discussion of energy prices is not longer related to expensive renewable energies. The lack of a market with just a few players is one of the often named reasons. With investments into renewable energy production in Europe the dependency from energy imports will decrease and this will help to stabilize the energy prices. First ideas of an integrated Extra-High-Voltage (EHV)-Network were developed starting in the 1930s. The European Transmission System is developing after World War II until today. Load development leads to the installation of larger power plants and of Extra High Voltage (EHV)-Overhead lines to provide access to affordable electrical energy, stability and reliability of the EHV-Grid in Europe. Today, the EHV-Grid faces the issue of the installation of new types of power plants decentralised small scale and centralised large scale renewable energy. Picture 1 shows the energy consumption and energy exchange between the borders of European countries. September 18, Copyright 2004

6 DEVELOPING EUROPE'S POTENTIAL FOR USING RENEWABLE Picture 1: Consumption of electrical energy, Europe 2004 (values in TWh; source: VDN-Berlin) Most of power plants in Europe are older than 40 years. Refurbishments prolonged the lifetime, but the need for new capacity is obvious. With the development of new power plants there is the need to consider the new participant in the energy market the renewable energy production. The former strategy of base load medium load peak load needs to be adapted to the new power plants, especially wind and solar energy. Table 1 shows the existing power generation, peak load and energy consumption for Europe in September 18, Copyright 2004

7 Region Capacity Peak Load Consumption Population (GW) (GW) (TWh) (Mio. citizens) UCTE (Blue) GB / IRL (Light orange) NORDEL (Green) UPS / IPS (Orange) Table 1: Installed capacity power plants Europe / peak load and consumption 2004 (source: Eurelectric) The main objective of the European community is the increasing share of renewable energy production. Main contribution is expected by the installation of offshore wind power plants. The challenge is the size of this type of power generation. Projects in Germany have a size of 80 wind energy converters (WEC) with an expected generating capacity of more than 400 MW. Clusters of offshore wind power plants can have a size of more than MW. Table 2 gives information concerning the contribution of offshore wind power. With 32 GW installed offshore wind power plants expected in 2020 with supply towards UCTE-points of common coupling approx. 6 % of consumption of the European Community can be provided. The majority of this wind power is expected to be installed in the North Sea (see September 18, Copyright 2004

8 Picture 2)! For Germany, the expected capacity of offshore wind power plants in 2020 of approx. 20 GW can produce more than 80 TWh. With a total consumption in Germany of more than 500 TWh this is a share of more than 16 %. September 18, Copyright 2004

9 Region Capacity Capacity Proportion Consumption Generation Proportion Offshore Offshore Wind Wind (GW) (GW) (%) (TWh) (TWh) (%) UCTE (Blue) GB / IRL (Light orange) NORDEL (Green) UPS / IPS (Orange) , , , Table 2: Offshore wind potential 2020 compared with installed capacity power plants and energy consumption 2004 Picture 4 shows the regional distribution of offshore wind power plants. The majority is located in the North Sea, in the British, Danish, German, Dutch and Belgium part of the North Sea. To provide transport of the offshore wind energy, the refurbishment of the existing onshore EHV-grids is probably not the best way to proceed. Due to the west east orientation of offshore wind (following the wind potentials from Ireland to Scotland, the shores from Belgium to the Netherlands, Germany and Denmark) a grid structure shall follow this west east - orientation. A possible solution is described in the following chapters. September 18, Copyright 2004

10 DEVELOPING EUROPE'S POTENTIAL FOR USING RENEWABLE Picture 2: Offshore Wind Power Plants Perspective 2020 (values in TWh, source: own) 2 T I M E S C H E D U L E O F F S H O R E W I N D S C E N A R O S STATUS OF OFFSHORE WIND TURBINES MORE THAN 400 MW RATED POWER Offshore wind turbines are available with a rated power of more than 5 MW (manufacturers: ENERCON, MULTIBRID, REPOWER). With a number of 80 turbines applied for in Germany the rated power of an offshore wind power plant is 400 MW. Considering the number of approved projects in Germany with a number of projects approved and located close together clusters of more than MW seems possible (see Picture 3). September 18, Copyright 2004

11 Picture 3: Offshore wind power projects in the German Exclusive Economical Zone, western North Sea Offshore wind experience today was gained by countries like Denmark, UK and Ireland. The rated power of all existing offshore wind power plants today is less than 800 MW. With the installation of the Q7-project in the Netherlands another country appears on the offshore stage. Compared to this, projects in Germany are one big leap forward in the offshore wind technology. The number of turbines is equal, compared to other projects. But: ecological interests (German Waddensea., visual impact ) change the other figures drastically. Distances of more than 100 km to the point of common coupling, distances to shore of more than 60 km, water depths of more than 20 m are a challenge for the German projects. With this physics and the German tariff system for renewables (9.1 ct/ kwh max.) the use of powerful offshore wind turbines is must. September 18, Copyright 2004

12 Description Existing projects Planned projects (Germany) Number of turbines: maximum 80 maximum 80 Rated power of turbines: maximum 3.6 MW minimum 5 MW Rated power of power plant: maximum 180 MW minimum 400 MW Water depth: maximum 20 m more than 20 m Distance to point of common maximum 30 km more than 100 km coupling Table 3: Vital statistics of offshore wind power projects in Europe 2.2 PHASE 1 UNTIL FEASIBILITY During this time period the feasibility of large scale offshore wind power plants in Germany needs to be provided. Foundation solutions for multi-megawatt-turbines, advanced grid connection concepts need to provide evidence for the financial community. The German government introduces a German pilot project, comprising 12 multi-megawatt-turbines and a rated power of more than 60 MW. Grid connection shall be done by using classic AC-solution. This project shall be installed during the period of Responsibility for the installation is with the major German utilities (E.ON Energy, Vattenfall Europe and EWE). Projects with even larger distances to the point of common coupling are planning there grid connection by using the more promising HVDC-technology. The innovative concept of self-commutated converters can be the first step towards an offshore grid structure. BARD Engineering intends to start the installation of there first project using the self-commutated converter concept in Together with ABB-experts BARD is working on the grid coupling solution, not only providing grid connection for the first projects of BARD but additional for the adjacent projects. At the end of 2006 the proof of feasibility for a MW concept should be available. Another milestone in the development of offshore wind farms in Germany is the concept for the crossing of Norderney island. With a maximum width of 8 m experts developed a concept to install cables for 9 offshore projects and a total capacity of MW over the island. This can although contribute to an offshore grid structure. With respect to grid September 18, Copyright 2004

13 coupling solutions, until 2010 we will see direct connections between the offshore wind power plant and the point of common coupling. Picture 4: Grid concept Offshore Wind Power Plants western part North Sea, German EEZ 2.3 PHASE 2 UNTIL 2015 LOCAL CLUSTERS With the proof of feasibility in 2010 / 11 the installation phase for many offshore wind power plants is expected to start. More manufacturers for multi-megawatt-turbines will manufacture there turbines at locations close to the waterfront with a serious output of turbines. Installation and operation procedures are proven and the financial community become more and more familiar with the offshore wind. High prices for electrical energy due to the demand of fossil fuels worldwide will contribute. The main risk for offshore wind farms are damages to the export cables, caused by anchors, fishing boats or other reasons. The use of interconnections between neighbouring projects will limit that risk and therefore affect the costs for insurance of offshore wind power plants. Until 2015 there is enough capacity in the existing onshore-ehv-grid (see DENA I - study). Picture 5 shows the expected status in the western North Sea until September 18, Copyright 2004

14 Picture 5: Phase 2 Until 2015 local offshore wind power plant cluster 2.4 PHASE 3 STARTING FROM 2015 NEW EHV-GRID-STRUCTURES Investigations of German utilities are showing the need for large grid modernization after Unfortunately, just solutions for the German utilities are investigated in studies like DENA I. During the studies the utilities draw one conclusion: Large scale offshore wind power is not a local issue, it is a European one. With a press release from February 22 nd, the UCTE announces the start of the European Wind Integration Study (EWIS). Most scenarios of the utilities focus on the onshore-ehv- Grid. Experts from the renewable community doubted that way the installation of an offshore grid shall contribute to grid stability, balance of power, market improvement far better compared to the refurbished onshore grid. The offshore grid follows the way of troughs of low pressure (troughs) from Ireland to Scotland, Denmark and Germany. It can contribute in avoiding existing onshore-bottlenecks in North-South direction in the Eastern North Sea. Chapter 3 gives further information on the economical benefits of the offshore grid. With the offshore-grid the investments for grid connection of the existing offshore wind power plants can be used. With the direct current (DC) - solution of self commutated converters, a multi-terminal- DC-grid can be established offshore. Picture 6 shows a concept for connecting the offshore wind power plants in the German North Sea (West) and the perspective of installing links to other countries. September 18, Copyright 2004

15 Picture 6: Grid structures offshore after 2015 Interconnected offshore wind power plants 3 ASSESSMENT OF ECONOMICAL SITUATION OF AN OFFSHORE GRID For bulk power transport with the need to cross large distances of ocean, HVDC is the state-of-the-art technology. With the classic line commutated converter concept, a multi-terminal-link was established in Canada. No other projects are available. Studies, for example the HPTS-study dealing with an 11- converter-concept feeding a 4-GW-DC-links showed the feasibility of that type of DC-technology. During the last years, the self-commutated converter concept was pushed by the company ABB. At the end of 2006, the second 350-MW-link shall be commissioned between Finland and Estonia. With this September 18, Copyright 2004

16 technology multi-terminal-solutions shall be possible to establish. Further studies have to follow this interesting technology. 3.1 METEOROLOGICAL EFFECTS OF OFFSHORE WIND POWER PLANTS The offshore-ehv-grid followed the troughs, travelling from West to the East. After installing large quantities of offshore wind turbines in the Irish and Scottish sea new overhead lines in England are mandatory. Is the trough approaching Ireland the energy transport of the exceeding amount of offshore wind power can be transported from West to East by establishing a link between offshore wind projects between Ireland and UK. Following the way of the trough, the huge capacities of Scottish wind energy can be transported toward Ireland when the trough leaves Ireland. With the installation of a connection between offshore wind power plants between Scotland and Germany energy transport from west to east can be established. After all, the trough reaches Germany, the load flow between Germany Scotland and Ireland is from East to West (see Picture 7). Picture 7: Route of troughs two scenarios 1. High Wind GB Load Flow from West to East 2. High Wind DE / NL / DK Load Flow from East to West Another possible meteorological scenario is a trough in northern Europe with no wind in Central Europe. During this case, the offshore grid avoids the bottlenecks between Denmark - Germany and the one between Germany and the Netherlands. If there is a trough in the Netherlands than it can be just the opposite, that means energy transport from south to north (see Picture 8). September 18, Copyright 2004

17 Picture 8: Wind Scenarios High Wind DK Load Flow from North to South 3.2 APPROVALS FOR EHV-GRIDS ADVANTAGE FOR SUB- SEA-CABLES The acceptance of overhead lines onshore is decreasing. Approvals for new overhead lines sometimes needs more than 10 to 15 years until they are obtained. EHV-AC-cables are not a solution for bulk power transport over long distances. Results of DENA I study showed the need for long distance lines. Therefore, the progress for installing offshore wind power plants can be negatively effected by insufficient EHV-onshore grids. Approval schedules for sub-sea-cables are critical in environmental sensitive areas. With the approval of the connection of the offshore wind power plants, the cable corridors are existing in There is just the need for the approval of cables connecting the respective offshore wind power plants, i. e. in the open sea, which seems not to be risk to receive the approvals with respect to time schedules. 3.3 EHV-OFFSHORE-GRID CONTRIBUTION TO AN OPEN ENERGY MARKET The development of offshore wind turbines is not finalised. Turbines of rated power of 8 MW or higher seems feasible. EWEA expected energy production costs for large offshore wind turbines of less than 4 ct / kwh (EWEA). With these turbines, the investment and life cycle costs of an offshore wind power plant shall be comparable to fossil fuel power plants, at least, if the grid connection costs for offshore wind power plants are not considered as part of the power plant. The offshore grid connects in west-east-direction the wind resources of central and north Europe and, if offshore wind energy is market capable, provides competition. With respect to north-south- September 18, Copyright 2004

18 connections, the renewable water potential of Scandinavia can be introduced in the offshore grid. Stability of energy prices can be expected by introducing the offshore-ehv-grid. If the European Transmission System operators agree to change the balance power market into an European Market the west-east-interconnection will reduce costs for balance power drastically. 4 NEXT STEPS The investigations to the offshore grid must begin soon. The grid shall interconnect offshore wind power plants between Ireland and Scotland, Scotland and Germany, Germany and Denmark and Germany and the Netherlands (with the option from Netherlands to Belgium). Load flow scenarios need to be developed and verified by meteorological studies. Transient stability studies are to be performed by universities. With the results of the electrical analysis (feasibility of an offshore grid) the investigations on routing and financing need to start. The feasibility study shall end with a time schedule for the respective sub-sea-cables. Today, the prices for offshore wind energy are described in different laws in the respective countries. The offshore grid shall be operated by an independent system operator. The organisation of payments for the connected offshore wind farms is a challenge, that offshore wind power plants in the Baltic Sea facing today. The project Kriegers Flak is located in Denmark Sweden and Germany. It is obvious, that a link between the offshore wind power plants is not just a connection between offshore wind power plants but a link between UCTE and NORDEL! The main obstacle to start the feasibility study is the lack of models for the UCTE and NORDEL grid. If it comes to the participation of the European Transmission System Operators, there is the risk of a slowdown of the project. There is the need for public models provided by ETSO for independent calculations, performed by universities or engineering companies. Models are available at companies like ABB, AREVA or SIEMENS, but these companies are not allowed to make information public. September 18, Copyright 2004