Community Wind Handbook/Understand Construction Process
Understand the Construction Process
The scope and scale of a large community wind project dictates that you should hire a qualified party with previous wind turbine installation experience to coordinate and conduct the construction portion of your project. Project developers can also utilize turbine vendors who may be willing to install the project.
Though the construction process can vary, it typically involves multiple steps that can include: site preparation, running and trenching of cable, foundation engineering and construction, electrical upgrades for interconnection, tower erection, nacelle and hub attachment, blade assembly and attachment, and site restoration.
Site preparation for large community wind projects will most likely start with the development of access roads to move components and provide routes for the heavy equipment necessary for the installation.
Site grading may be required to provide a level surface for cranes. In addition to this, grading may be needed for a temporary storage area prior to the delivery of turbine parts and components.
To connect turbines to transformers and transformers to the interconnection point, cables must be laid underground or installed aboveground. The decision on how cables are installed should be made during the permitting process and should be based on cost, land-use and wildlife impacts, and maintenance requirements. Additional electrical work may be needed to complete the installation. This will include any upgrades required in the interconnection agreement.
The type and size of turbine, along with the individual site, will dictate foundation specifications. Engineering will be required during foundation design and construction. Foundations may require between eight and 20 truckloads of concrete per foundation to complete. Multiple foundation types have been used in wind projects.
Wind turbine towers for large community wind projects are typically sectioned and must be assembled utilizing a crane. Successful tower assembly and construction allow the remaining components to be attached.
Following tower assembly and construction, the turbine’s nacelle is lifted and attached. The nacelle is the home of multiple components including the drive shaft, gearbox, generator, electronic controls, and other associated equipment.
Once the nacelle has been added to the project, the turbine’s hub is lifted and attached. The hub is the main component between a turbine’s nacelle and blade assembly. Once it has been installed, turbine blades are assembled, lifted, and fastened to the hub.
Once construction is complete, the surrounding land should be restored to its original condition.
Videos are available that depict the construction process. The Bureau of Land Management’s website features a slideshow highlighting the construction process for the Milford Wind project in Milford, Utah. An additional example of the construction process is Case Western Reserve University’s Wind Turbine Time Lapse Installation Video.