At the end of 2009, Germany had a total of 21,164 wind turbines installed with an output of 25,777 MW (compared with 23,902 MW at the end of 2008.
The produced electrical energy from wind farm amounted to 37.5 TWh, compared to 40.4 TWh in 2008. Assuming that 2009 would have been a minimum supply of wind in relation to long-term wind data one could expect a theoretical energy output of 41.5 TWh.
Although investment in Germany’s economy decreased by 12.5% in 2009 because of the world economic crises, the renewable energy sector increased its investment by 20%. Investment in the wind energy in Germany was 2.65 billion € and has proven to be a stabilizing factor of the economy.
About 90,000 people in Germany were employed in the wind power sector in 2009. Electricity from wind energy has in the medium term the largest potential among renewable energies in Germany for meeting the 30% goal for electricity from renewable energies set by the federal government. An important share of electricity from wind farm will need to be produced by offshore wind farms.
A very important step for Germany on this technological path was the construction of the offshore test site alpha ventus in 2009. Alpha ventus was planned as a test site for the modern 5-MW wind turbine class under harsh marine conditions.
In order to maximize the experience and knowledge from alpha ventus for future offshore wind farm projects and wind turbine development at a high scientific and technological level, the Federal Environmental Ministry launched the accompanying RAVE (Research at Alpha VEntus) research initiative. So far, they have spent 36 million € on 25 research projects.
Another important event in 2009 in Germany’s wind energy research was the formation of the Institute for Wind Energy and Energy System Technologies (IWES) at the Fraunhofer-Gesellschaft.
IWES will be a focal point for wind energy research in Germany networked with other important research institutions in Germany, Europe, and worldwide.
Germany pledged to the European Union that it will produce 18% of its overall energy requirements from renewable sources by 2020. Today the share is 10%. For the electrical energy sector, where the share of renewable was 16% by end of 2009, the goal is even more ambitious: 30% from renewable by 2020.
In 2009, the financial crisis did not seem to have a visible impact on the installation figures with even more capacity installed than in the previous year (1,665 MW installed in 2008 vs. 1,916 MW in 2009). Development in 2010 therefore promises to be interesting, particularly concerning offshore installations.
The advanced planning underway at the end of 2009 for 300 to 400 MW offshore will have a positive effect on these figures, provided there are no delays due to bad weather or lack of availability of offshore installation equipment.
The amendment of the Renewable Energy Sources Act (Erneuerbare-Energien-Gesetz, EEG) came in to force in January 2009. It turns out to be the main stimulation for the German wind market and it especially will accelerate offshore development in Germany.
According to information from turbine manufacturers, 76 wind turbines with a total installed power of 36.7 MW were decommissioned in 2009 (repowering in 2008 was 32.9 MW). In their place were installed 55 wind turbines with a total installed power of 136.2 MW. For such repowering, the EEG guaranties an extra payment of 0.005 €/kWh to the basic tariff of 0.092 €/kWh. Repowering has become a growing factor of wind energy implementation in Germany.
Compared to 2008, market shares of wind turbine manufacturers have shown only minor changes. The wind turbine manufacturer Multibrid is a newcomer in the market with a share of 1.6%. Two significant shifts in market shares have been the increase of Enercon and the decrease of Vestas. Enercon claimed a market share of 60%, while the market share of Vestas fell from 31.6% to 19.5%.
The three leading manufacturers on the German market for wind turbines installed in 2009 were Enercon, Vestas, and Repower Systems.
The major development of 2009 was the commissioning of Germany’s first offshore wind farm “alpha ventus” in the North Sea (45 km north of the island Borkum). This major event finally took place after years of delay and after 29 offshore wind farm projects with 1,894 wind turbines had been approved by the Federal and State Authorities since 2001.
The alpha ventus wind farm is the first step of the German wind energy industry into the water. Alpha ventus is not only a conventional wind farm but also a test site for 5-MW offshore wind turbines. It consists of six Areva Multibrid M5000 wind turbines mounted on tripod foundations and six REpower 5M wind turbines on jacket foundations in 30 m water depth.
The 12 wind turbines were placed in a grid-like formation with distances of approximately 800 m between each turbine. Four rows form a rectangle having a total surface area of 4 km2 – about the size of 500 football pitches. With its total capacity of 60 MW, a yearly energy yield of approximately 220 GW hours is expected, which is equivalent to the power consumption of around 50,000 households. The external conditions at this site have been investigated by the FINO 1 research platform since 2003.
The construction started in the sea in the middle of April 2009. By 1 June 2009 the first milestone was reached when the six tripod foundations had been anchored. During the pile-driving of one of the tripods, scientists of the University Hannover tested a bubble curtain as a damping system to reduce sound emissions caused by the ramming of the piles.
The implementation of the acoustic damping system was a challenge due to time restrictions and logistic requirements. Despite an incomplete operation, caused by a failure of a part of the system, a sound reduction effect was detected of about 12 dB in the direction of the sea current. On 15 July 2009 Germany’s first offshore wind turbine, a M5000 in deep water and far away from the coast, was completed.
During the construction of the remaining five M5000s, the construction of the six jacket foundations for the 5M wind turbines started in June 2009. This process used the world’s largest crane ship Thialf as a platform. The last 5M was completed on 16 November 2009.
The wind farm can be seen by a web cam from the FINO 1 research platform which is located 405 m from the first turbine (for more information visit www.alpha-ventus.de/index.php?id=84#c47).
Offshore Wind Research Programme RAVE
In order to maximize the experience and knowledge gained from alpha ventus at a high scientific and technological level, the Federal Environmental Ministry launched the accompanying RAVE research initiative.
Under this initiative 25 projects have so far been supported at the cost of 36 million €. Industries, universities, and other research organizations are working closely in a research network, which has greatly enhanced the cooperation amongst German wind energy researchers. The results of RAVE will contribute considerably towards ensuring that future wind farms can be planned on a new scientific and technological knowledge base.
The main focuses are reducing costs, increasing efficiency, advancing the availability of wind turbines, improving the technology for developing offshore wind energy, ensuring ecologically responsible application, as well as technologically optimizing wind turbines with regard to their environmental impact.
The RAVE research initiative consists of a variety of topics and projects in connection with the installation and operation of alpha ventus. In order to provide all participating research projects with detailed data, the test site is equipped with comprehensive measurement instrumentation.
At two wind turbines next to research platform FINO 1 about 1,200 sensors are installed. As part of the RAVE initiative, the participating institutes and companies have so far set up projects on the following topics:
• Realization of joint measurements and data management
• Analysis of loads, modeling, and further development of the different components of offshore wind turbines
• Measuring loads on offshore foundations and structures
• Further development of LIDAR wind measuring techniques
• Grid integration of offshore wind energy
• Monitoring of offshore wind energy utilization in Germany – “Offshore WMEP”
• Measurement of operating noise and modeling of sound propagation between the tower and water
• Ecological and oceanographic research
New research institute — IWES
The new wind energy research institute IWES was founded on 1 January 2009. It consists of the former Fraunhofer Center für Windenergie und Meerestechnik CWMT in Bremerhaven, and the Kassel Institut für Solare Energieversorgungstechnik ISET. Furthermore, Fraunhofer IWES will establish two Fraunhofer project groups in Hanover and Oldenburg.
The Institute is networked among other national and international partners especially with the ForWind wind energy competence group of the Universities of Bremen, Hannover, and Oldenburg. Presently, 240 scientists, appointees, and students are employed at the IWES. Main research topics include:
• Engineering and operation of wind energy turbines and parks
• Investigation, development and test of components: rotor, drive train, and foundations
• Fluid elasticity and dynamics
• Offshore site condition assessment for wind and ocean energy technology
• Control and system integration of decentralized energy converters and storages
• Energy management and grid operation
• Energy supply structures and systems analysis.
IWES facilities incorporated a test center for rotor blades of up to 70 m in length and another future center for rotor blades of up to 90 m in length is under construction. This allows IWES to test the statics and dynamics of current and next-generation rotor blades and their components, thus contributing to their optimization. Closely linked with experimental and numerical procedures a variety of activities are scheduled, such as the development of new test methods, endurance tests, and tests of new construction
New wind turbines
A ‘BARD VM’ wind turbine was tested in 2009 under near-shore conditions at a location in the Jade Bay near Wilhelmshaven. The wind turbine is mounted on BARD’s own developed tripile foundation. The near-shore wind turbine, which has a rated power of 5 MW, is about 400 m from the coast line. The aim is to test the whole design of the turbine including the foundation.
BARD will use 80 wind turbines of this type for BARD’s first offshore wind farm in the North Sea. The transformer station was installed in June 2009 and construction of the wind farm started in March 2010.
Another new wind turbine developer is Schuler Pressen GmbH & Co. KG, Göppingen (Schuler). As a market leader in molding presses for automobile production, Schuler has much experience in the technical management and transformation of large loads and forces, as is the case also in wind energy converters. Schuler developed a 2.7-MW direct-drive turbine with a permanent magnet synchronic generator.
The wind turbine was especially designed for inland locations with middle wind potentials and possesses low operational sound emissions. A frequency converter and transformer are mounted in the tower base so that the nacelle weight could be minimized. The first prototype will be installed in 2010. Furthermore, the Federal Ministry for the Environment (BMU) funded Schuler’s development of the basic design of a 6.5-MW offshore turbine.
In 2009, the BMU funded 45 new projects with a total of 28.2 million €. The budget for wind energy research and development has been significantly growing over the last years. A main focus of the research is the development of technologies for offshore wind energy information about the whole spectrum of wind energy research funded by BMU will be given in the brochure INNOVATION THROUGH RESEARCH 2009 Annual Report on Research Funding in the Renewable Energies Sector.
Authors: Joachim Kutscher, Forschungszentrum Juelich GmbH, PtJ; Ralf Christmann, Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), Germany. www.ieawind.org