Info 3
Research at the offshore wind energy test site alpha ventus:
There is nothing that cannot be
improved
Project leaders and partners:
R&D themes at alpha ventus:
• Technology and Monitoring
• Foundation and Construction
• Grid Integration
• Ecology and Safety
• Measurements, Instrumentation
and Data Management
• Operation and Co-ordination
Photo: DOTI / alpha ventus
Profitable, cost effective and durable
Coordinator:
Project supervisor:
Funded on the base of
an act of the German
Parliament by:
„Alpha ventus“, the first German offshore wind park testing and demonstration project,
is initiating the utilisation of wind energy in the German North and Baltic Seas. In the
associated German research initiative, RAVE, researchers are carrying out various
measurements and investigations to further promote Germany as being the leader in
wind energy technology. The main focuses are the reduction of costs, increased efficiency, advancing the availability of wind turbines, improving the technology for developing offshore wind energy, its ecologically responsible application as well as technologically optimising the turbines with regard to ecological impact.
A firm foundation
Whoever has stood on a beach or the deck of a ship during a storm can well imagine
what forces 1000 ton wind turbines are up against in the raging sea. Two newly developed steel foundations are used at the „alpha ventus“ offshore wind park. The first
uses a “tripod” concept and looks like a splayed out three-legged foot. The second
type has a so-called “jacket” foundation which uses as many similar parts as possible.
In addition the project RAVE Foundations investigates the effects of wind, waves and
operations on the foundations. A further subsidiary project, RAVE GIGAWIND av, intends to improve the supporting structure through an integrated dimensioning concept
and to develop it into a commercially mass-produceable item. The RAVE Geology project investigates the ocean floor and particularly its suitability for offshore construction.
Developing and optimising new technologies
2007: Design of test site and
research projects on utilisation
of wind energy at sea
2008: Preparation of measurement and data management;
construction of infrastructure and
offshore transformer station
2009: Erection of wind turbines
and commissioning of measurement sensor system
2010: Initial operation experiences and first research results
2011: first complete year of
operation,15 % more energy as
predicted (4450 full load hours,
up to 97 % availability)
Before the construction of offshore wind parks begins on a larger scale, it is imperative
to incorporate the experience and knowledge gained from the planning, construction
and operation of the „alpha ventus“ test site into further developing and optimising the
technology. Further rotor blade development will be the focus of the RAVE REpower
Blades project while the interdependency of the overall system will be analysed by
the RAVE REpower Components project. The improvement of selected components will
be the responsibility of the RAVE AREVA Multibrid M5000 Improvement project. In the
project, RAVE OWEA, key aspects of the reliable design and operation of offshore
wind turbines are being verified. In the RAVE LIDAR (Light Detection and Ranging)
project the application of modern wind measurement techniques to offshore turbines is
being investigated as well as potential improvements to operations management.
Finally, the monitoring project, RAVE Offshore WMEP, will record and interpret essential operation data to enable the determination of such matters as the influence of
particular meteorological conditions, energy revenues, peak load hours, downtimes,
electricity production costs, availability, maintenance and grid connection.
Bringing the electricity safely to and through the land
The energy from offshore wind parks must first be brought to land using subsea cables. The high-performance connections on land are used to transport the generated
electricity to load centers where much electricity is needed. In the RAVE Grid Integration project, strategies for the integration of offshore wind energy into the power grid
are being developed and implemented. The aim is to reduce balance energy and the
provisions for reserve power with the help of newly developed offshore wind power
prediction systems while at the same time ensuring the high availability and the safety
of the grid.
Keeping nature in mind
The goal of the complementary ecological research in the RAVE Ecology project is to
gain extensive knowledge of the impacts of construction and operation conditions on
the marine environment, for example, on benthos, fish, resting birds, migratory birds
and marine mammals. The main focus of the RAVE Geology project is to pursue the
The RAVE research initiative runs acquisition and evaluation of the sediment dynamical processes (scour) and overall
sand movement in order to obtain reliable information for the design basis of the offsimultaneously with the conshore constructions and the liquefaction behaviour of the upper seabed. In the RAVE
struction and operation of the
"alpha ventus" test site to attain Operational Noise project the underwater operational acoustic noise of the wind turbroad based experience and
bines, various boundary conditions as well as the overall noise stress for sea life and
knowledge for future offshore
particularly sea mammals are being determined. The RAVE Noise Reduction project is
wind parks. RAVE is sponsored
investigating noise reduction during the construction phase through pumping air bubby the Federal Ministry for the
bles into the water. The safety of wind parks will be
Environment, Nature Conservaenhanced in the RAVE Sonar project through the technical
tion and Reactor Safety (BMU)
integration of sonar transponders in the overall design.
following a resolution by the
Photo: Transport of a tripod foundation
© DOTI / alpha ventus archive
German Federal Parliament
and is co-ordinated by Fraunhofer IWES. It joints the scientific
activities of the plant manufacturers and a multitude of research institutions.
RAVE Project Coordination:
Dr. Bernhard Lange, Fraunhofer
IWES, [email protected]
Phone: +49-561-7294-272
http://www.rave-offshore.de
Editorial: Uwe Krengel, Michael
Durstewitz, Roy and Joanne
Emmerich, Fraunhofer IWES
Königstor 59, 34119 Kassel
Status: May 2012
Statement by Dr. Kurt Rohrig, Mechanical Engineer
Fraunhofer Institute for Wind Energy and Energy System
Technology IWES, Deputy Director Kassel
„Wind energy in Germany is a success story. It is now essential to take the next
step, far out at sea.
To this end we must not only bring together the wind energy branch with the
know-how of other offshore sectors but also solve new tasks and problems. As
many other cases have already shown, if this is done co-operatively and in a
well co-ordinated manner, it should be achievable. In other words: Yes, we can!“
Contact: [email protected], Fraunhofer Institute for Wind Energy
and Energy System Technology, IWES, www.iwes.fraunhofer.de