What's really happening inside your offshore turbines
While the industry focuses on blade erosion, gearbox failure, and foundation corrosion, a quieter threat is building inside the towers, nacelles, and hubs of offshore wind farms across the North Sea and beyond.
A climate designed for biological colonisation
An offshore wind turbine is not just blades and a tower. The interior is a complex industrial environment: a hollow steel tower rising 80–100 metres, a nacelle housing the gearbox, generator, controller, brake systems, yaw drive, and pitch systems, a hub behind the rotor where pitch bearings sit, and a transition piece connecting the foundation to the tower.
These are sealed spaces. Ventilation is minimal. Equipment generates significant heat. The marine atmosphere drives persistent humidity into every internal cavity. The nacelle has been compared to a Second World War submarine for its cramped, enclosed conditions.
Combined, these conditions create exactly the environment in which mould, mildew, and biological contamination thrive: warm, humid, dark, undisturbed for months between maintenance visits, and impossible to ventilate effectively.
What builds up between maintenance visits
The biological contamination inside an offshore turbine does not exist in isolation. It develops alongside and interacts with a complex mix of industrial contaminants.
Hydraulic oil and fluids are the dominant contaminant. A single turbine can contain as much as 1,400 litres of oil serving lubrication, hydraulic, and gear oil functions. Oil leaks are endemic — pools of oil dripping from hydraulic yaw brakes are so common that technicians treat them as routine.
Salt deposits and salt-laden moisture are the challenge that differentiates offshore from onshore. When salt absorbs humidity from the air, it accelerates corrosion and oxidation rates inside wind turbine structures.
And then there is mould. Internal towers with ventilation issues and high humidity create conditions where mould forms on surfaces throughout the interior. Mould is not just a surface contamination issue. It is a worker health and safety issue in confined spaces.
Your technicians are breathing this in
Wind technicians spend hours working inside these environments. They climb internal ladders coated in moisture and residual grease. They perform maintenance in nacelles where the air is thick with humidity and whatever the previous crew's cleaning chemicals left behind.
And here is the uncomfortable truth about current cleaning practice: the products most commonly used inside turbines were never designed for this environment. Brake cleaner. Generic solvents. Petroleum-based degreasers. Products high in volatile organic compounds that cause respiratory irritation and can trigger asthmatic attacks.
These products address oil and grease. They do nothing to address biological contamination. In many cases, they make the respiratory environment worse.
Biological contamination does not exist in isolation
The interior of an offshore wind turbine is protected by anti-corrosion coating systems classified under ISO 12944 CX (Extreme) — the harshest corrosion category. Signs of coating failure typically appear around year 5–6. The design lifetime target is 25 years or more.
Biological contamination interacts directly with this protective system. Mould and biofilm on coated surfaces can trap moisture against the coating, accelerating degradation. Any cleaning product that damages the coating system is solving one problem while creating a far more expensive one.
The chemical scrutiny is coming
A 2025 international study found that offshore wind farms could potentially release over 200 chemical substances into the sea, with 62 considered particularly relevant to the environment.
The regulatory trajectory is unambiguous: tighter controls on chemical emissions from offshore wind operations are coming. Operators who are still using petroleum-based degreasers inside their turbines are on the wrong side of this trajectory.
There is a better answer.
TurbineClean is the specialist biological contamination treatment formulated specifically for the conditions inside offshore wind turbines. Purpose-built for the problem nobody else has designed a product for.