A modular design splits a single component into separate sections. These sections connect to each other, rather than forming one solid block. LIGHTWIND is a Horizon Europe project. It is developing a lighter, modular drivetrain for floating offshore wind turbines. The project is exploring what this idea could mean for maintenance at sea.
This article explains what a drivetrain does, why most are built as one integrated unit today, and why that distinction matters more offshore than almost anywhere else.
What a drivetrain actually does
The drivetrain is the group of parts that turns the blades’ spinning motion into electricity. It typically includes the shaft, the bearings that support it, and the generator. The nacelle houses all of these parts. The nacelle sits at the very top of the tower.
On a floating offshore turbine, the nacelle sits dozens of metres above the water. The whole structure also moves with the waves. Every component inside has to keep working reliably in that environment, year after year.
Why most drivetrains are built as one integrated unit
Most drivetrains today form one tightly integrated assembly. Engineers do not design them to come apart piece by piece. If one internal part develops a fault, technicians often cannot simply open that one section. Reaching it can mean partially or fully dismantling the assembly around it.
A simple everyday comparison helps here. Think of the difference between a phone with a sealed battery and one where the battery slides out. In the sealed version, a single worn part can mean sending the whole phone away for repair. In the other, you replace just the part that failed. Most drivetrains today work more like the sealed version.
Why this matters more at sea
On land, a maintenance visit is usually straightforward to arrange. Offshore, reaching a turbine at all takes a vessel, a suitable weather window, and often specialist lifting equipment. That cost exists whether the repair is small or large. Getting there in the first place is the hard part.
This is a well-documented challenge across the offshore wind sector, not something specific to any one project. Industry research backs this up. Studies on floating wind operations show how much offshore access depends on sea conditions and vessel availability. This access problem can account for a significant share of a project’s lifetime costs (see this review of floating wind turbine operation and maintenance for more detail). This is why the size of the job matters so much once a technician reaches the turbine. It shapes how teams plan offshore maintenance.
What “modular” changes, in principle
A modular design splits a component into separate, interchangeable sections. These sections connect to each other instead of fusing into one block. In principle, technicians can work on each section individually. If one section fails, the rest does not necessarily have to come apart too.
Engineers have already explored this design principle elsewhere, from modular manufacturing to interchangeable parts in other industries. Applied to a wind turbine drivetrain, the idea works like this: splitting a component into sections could let technicians repair or replace only the affected section. They would not need to remove the entire unit. This remains a design aim. No one has demonstrated it yet on a full-scale turbine.
Open questions modularity still needs to answer
Splitting a component into sections is not free of trade-offs. More joints can mean more places where water, salt, or vibration could cause problems over time. A connection that works well in a lab test still needs to prove itself through years of real offshore conditions.
This is exactly the kind of question technical validation work exists to answer. It’s also why the language throughout this article stays cautious: modularity is a promising principle, not yet a proven fix.
Where LIGHTWIND comes in
LIGHTWIND is developing a lighter, modular drivetrain for floating offshore wind turbines. The design uses smaller units meant to connect together, rather than one large, integrated assembly. The project’s aim is to explore whether this approach can make maintenance easier to plan and carry out on turbines at sea.
The technology is still under development. Any maintenance-time benefit remains a design aim at this stage, not yet a demonstrated result.
What this could mean for the people doing the work
Modular sections might eventually reduce how much of a drivetrain technicians need to reach or remove during a repair. If so, the effects would show up first in the day-to-day of the job. Technicians would carry different tools out to the platform. They would spend a different amount of time on site. Teams would plan repairs around weather windows differently too.
That’s a question worth putting directly to the people who do this work. What would a shift like this actually mean for a technician’s job at sea?
Next step
LIGHTWIND will continue publishing updates on the project’s technical progress as results become available. To follow the project’s work on drivetrain design and maintenance, visit lightwind-project.eu or subscribe to project updates.