Keeping the blades turning

Aaron Blutstein 22 December 2025  

When most people think about wind power, they picture the vast white turbines turning steadily offshore or across open hillsides. What’s less visible are the complex systems inside those towers, the components quietly making sure those blades turn safely, efficiently and exactly as they should. At the heart of much of that work are hydraulic and actuation systems. Smart Machines & Factories reports.

Hydraulics might not get the headlines that blades, cables or generators do, but they’re essential. In every modern wind turbine, particularly those operating offshore, hydraulic power is used to pitch the blades, control yaw movement, apply brakes, and support a range of auxiliary functions. These systems are the muscle of the turbine – converting electrical power into precise mechanical movement that can respond instantly to changing wind conditions.

As the UK pushes to expand its offshore capacity, with targets for 50 GW of offshore wind by 2030, the demand for reliable, efficient and maintainable hydraulic systems is growing rapidly. The challenge is not simply producing more turbines, but making sure each one performs consistently in harsh conditions, often hundreds of miles from shore. That’s where hydraulics come into focus.

Offshore wind farms are unforgiving places for machinery. Saltwater, constant vibration, temperature swings and limited access for maintenance all add up to a tough working environment. Components that perform flawlessly in a factory or onshore setting can degrade quickly at sea. Hydraulic systems, with their seals, fluids and moving parts, need to be designed for resilience. Corrosion-resistant materials, robust filtration and carefully chosen fluids all make a difference to long-term reliability.

One of the recurring issues for operators has been maintenance. Accessing a turbine offshore can be difficult, especially during winter. Any failure that requires a technician to go out by boat or helicopter adds significant cost and downtime. For that reason, there’s been a strong move towards designing hydraulic systems that are not just durable, but also easier to monitor and maintain remotely.

Condition monitoring is becoming standard. Sensors that track pressure, temperature, and fluid cleanliness can send live data back to shore-based teams. With predictive analytics, operators can identify small issues before they turn into breakdowns. It’s not glamorous work, but it’s the kind of detail that keeps wind farms running smoothly.

Some turbine manufacturers are now experimenting with semi-closed or fully closed hydraulic circuits to minimise the risk of leaks and contamination. These systems maintain fluid purity and reduce the need for regular maintenance visits. Others are using modular actuation systems that can be swapped out quickly when required, rather than serviced in place. The goal is the same: maximise uptime and reduce costly interventions offshore.

The conversation about hydraulics in renewables also ties into a wider effort to make wind turbines more efficient and sustainable. Hydraulic systems have traditionally been viewed as less energy-efficient than purely electric alternatives, mainly due to losses in fluid compression and throttling. However, advances in design are closing that gap. Variable-speed pumps, proportional control valves, and better system architecture are helping to reduce energy losses significantly. In some cases, hybrid electro-hydraulic solutions are being introduced – combining the fine control of hydraulics with the efficiency of electric drives.

Digital integration

Reliability and efficiency are two sides of the same coin in this context. Every hour of downtime on a large offshore turbine can mean thousands of pounds in lost generation. With arrays stretching into the hundreds of machines, even small improvements in reliability can have a noticeable impact on overall performance. It’s why the supply chain around hydraulic components, from seals and hoses to accumulators and servo valves, is now seen as a strategic priority.

The UK’s growing offshore sector provides a real opportunity for the domestic fluid power industry. British companies already have deep expertise in hydraulics through industrial, aerospace and marine engineering. Translating that experience into renewable applications is a logical next step. There’s scope to supply systems for new builds, but also to support maintenance, upgrades and retrofits on the growing number of operational turbines.

Localising more of the supply chain would not only reduce lead times but also build resilience against global disruptions. The events of recent years have shown how quickly shipping delays or component shortages can affect major infrastructure projects. Having a base of UK-based hydraulic and actuation specialists who understand offshore requirements is both an economic and strategic advantage.

Training and skills are part of that picture too. The demand for technicians who can design, assemble, test and service hydraulic systems for renewables is growing faster than the current workforce can supply. This is an area where collaboration between industry and training providers could have an immediate impact. Apprenticeships, conversion programmes and short technical courses could bring more people into the field relatively quickly.

Innovation in materials and digital integration is another area gaining momentum. New coatings and composite materials are improving corrosion resistance, while additive manufacturing is allowing for more compact and efficient designs. Meanwhile, the use of digital twins – virtual replicas of real components – means that hydraulic systems can be tested, simulated and refined long before they’re installed offshore. This not only speeds up development but helps anticipate wear and performance issues before they occur in the real world.

One point often raised is whether hydraulics will remain dominant in turbine design as systems become larger and more powerful. Some manufacturers are already moving towards all-electric pitch systems. However, hydraulics still hold several advantages, especially for large offshore turbines. They offer higher force density, proven reliability, and better resilience against overloads, all critical factors when each blade can be longer than an airliner’s wing. It’s likely that for the foreseeable future, hydraulics will continue to play a major role, possibly in hybrid forms that combine the best of both technologies.

Beyond the turbines themselves, hydraulics are also vital across the wider offshore renewable ecosystem. Installation vessels, jack-up rigs, cable-laying ships and floating platforms all rely heavily on hydraulic systems for lifting, positioning and stabilisation. The move towards floating wind, a key part of the UK’s future capacity, will only deepen that dependency. Mooring systems, ballast control, and tensioning equipment are all hydraulic domains.

As the offshore sector grows, so does the need for a joined-up approach between fluid power specialists, turbine manufacturers and operators. It’s not just about supplying components, but about designing systems holistically from the control logic to the seals and fluids. Building those relationships early in project development can prevent costly redesigns later.

If there’s a common thread running through all of this, it’s that the future of hydraulics in renewables will depend less on radical reinvention and more on refinement. The basic principles haven’t changed much in decades, but the expectations around reliability, monitoring, sustainability and integration have. That’s where the real progress is happening.

Hydraulics might never be the headline act in renewable energy, but without them, many of the UK’s most ambitious projects simply wouldn’t turn. The opportunity now lies in making those systems smarter, cleaner and better suited to the demands of the offshore environment.