nezzy² - Floating Wind Turbine System
80 % of the global wind energy potential is offshore, in order to exploit this potential, appropriate technologies must be developed and used. In contrast to bottom-fixed foundations, floating foundations can be used in almost all water depths greater than 40 m. The use of floating foundations also offers many other technological and economic advantages. Additional to these advantages, the ecological advantages are very important. Due to the lack of piling work, noise emissions during installation can be avoided and complete dismantling is possible. The complete product life cycle has already been taken into account in the design, so that the ecological footprint is kept as small as possible. In addition to risk minimization, ecological and economic aspects were decisive during the entire development process.
aerodyn engineering as a decades experienced turbine designer is developing the cutting edge floating wind turbine system nezzy². The system is extensive tested in wave tanks and offshore in different scaled models.
A nezzy² floating wind turbine system with a rated capacity of 16.6 MW is in production and will sail out in 2023.
Driven by today’s hands-on experience to cut offshore costs significantly, nezzy² is a fully integrated system approach based on an inexpensive floating main body made of pre-casted and post-tensioned concrete elements. Key elements are:
- Two Counter rotating rotors ? Balanced rolling moment
- Downwind, self-aligning system ? No yaw system, reduced RNA weigh
- Turbine interface flange for drive train integration ? different turbines applicable
- Tower with aerodynamic shaped structure ? Low drag, low tower-blade interference and support of self-aligning
- Pre-tensioned synthetic guy ropes for load transfer ? Reduced tower bending loads and weight
- Foundation built from pre-casted, post tensioned concrete segments ? Cost-effective and time-saving series
- Segmented ellipsoid GFRP floater ? Optimized buoyancy and low drag force
- Turret Mooring System ? Easy disconnection of mooring
- Synthetic mooring elements ? Mitigation of loads and costs
Driven by rising electricity and material costs, aerodyn engineering opted for a cost-reducing and highly innovative design path. The key design principle is to adopt low-cost and advanced tech-nology to obtain a competitive structure. For this effectiveness, the entire product life cycle has been considered, including design, manufacture, assembly, commissioning, installation, operation, maintenance, repair and disassembly of components and recycling.
- 30% less RNA total weight for two turbines than one single turbine
- No roll inclination due to torque compensation of counter rotating rotor
- Low wind misalignment by using a coordinated rotor thrust controller
- 2-4 % higher specific energy yield due twin rotor compression effect
- Scalable foundation dimension for different sites and wave conditions
- Excellent swim stability with low acceleration in all directions
- Cost efficient mooring system by use of low drag components in air and water
- Use of available and reliable proven turbine size 7-10 MW from different OEM’s
- Suitable for water depths of only 40 m