Nacelle cover design for wind turbine

In FRECON, we have strong competencies within composite constructions and have provided support on a two-digit number of nacelle cover solutions to several of the largest wind turbine manufacturers.

In the collaboration with Envision Energy, we succeeded in transforming a basic nacelle cover design into a producible and functional cover with the correct strength to survive a “50 year storm”, and moreover with a strong focus on the customer’s total cost of ownership and specific customer requirements.

30% reduction in material weight and efficient mouldings have contributed significantly in making our basic design a succes and in ensuring that the cooperation with FRECON resulted in a significant reduction in our ’total cost of ownership’.

Uffe Lykke Eriksen
Turbine Chief Engineer, Envision Energy

The task:

Envision Energy came up with an exciting, innovative, challenging, and aesthetic basic design that consisted of an eggshell form in solitary 3D surface. To mature this eggshell into a final nacelle cover, FRECON parameterized it. Such a complex 3D surface required the right qualified competencies, thus in FRECON we could benefit from our many years of experience in considerations of multiple and simultaneously parameters such as design requirements, functions, structural integrity, production, and cost price.

FRECON’s close and efficient integration method

By using FRECON’s methodological approach to construction work and our unique and effecient integration between design and calculation software, we could implement particularly many and fast iterations on optimizing of physical design and on the product’s structural properties. Hence, in this nacelle cover project, this method allowed us to utilize the double curved surfaces to quickly and efficiently give the nacelle cover more strength while at the same time reducing the material thickness.

Construction in thin fiber layer

“In the cooperation with Envision Energy, we transformed the basic design from a predominantly sandwich construction into a single skin with a minimal consumption of foam and with built-in beams in the particularly exposed places. These strategically placed reinforcements were to ensure that the nacelle cover could withstand e.g. the snow and wind loads it is exposed to.
Moreover, this type of construction also made it possible to construct the nacelle cover in a thin layer of fiber without losing the strength of the construction. This was a great cause of why we so rapidly could succeed in reducing 4.8 mm to 4.0 mm glass fiber and remove large parts of the foam reinforcement,” says Rasmus Gottlieb Jakobsen, Lead Design Engineer in FRECON.

In addition, FRECON got great opportunities to think innovative to cost optimize and innovate features for the nacelle cover. For example, this allowed the cooling intake to the gearbox to be directly integrated into the nacelle cover, which reduced the final number of molded parts.

“We managed to construct a nacelle cover with suitable draft angels and thus with an efficient moulding ejection. This gave Envision Energy a quick and smooth moulding, and a subsequent very simple assembly,” says Peter Laugesen, Lead Design Engineer i FRECON.

Today the nacelle cover can be seen on Envision Energy’s beautiful and innovative ‘Onshore Smart Wind Turbine 2.X MW’, which is known for providing maximum performance, optimizing energy yield, and minimizing downtime.