Same Location – More Power

Fewer turbines, more capacity, higher yields: repowering wind farms opens up new perspectives for the expansion of wind energy. Modern technology makes it possible to generate several times more electricity at proven sites without using additional land. This approach is becoming increasingly important in accelerating the energy transition and further strengthening wind power as a cornerstone of Europe’s energy supply.

The term repowering literally means “renewing power plants” and describes the targeted modernization of existing energy facilities. In wind energy, this involves dismantling older wind turbines and replacing them with a smaller number of modern, more powerful turbines, while retaining the site and infrastructure. The new generation of turbines operates far more efficiently and enables significantly higher electricity production on the same area of land. Installing modern wind turbines brings numerous benefits, ranging from higher energy yields and improved noise and biodiversity protection to more efficient land use.

Size and Capacity: The Evolution of Turbine Technology

Over the past decades, turbine technology has undergone an impressive leap forward. While wind turbines in the mid-1980s had hub heights of around 40 meters and rotor diameters of about 30 meters, today’s new installations typically reach hub heights of 146 meters with rotor diameters of 151 meters.

These dimensions pay off: with every additional meter of height, electricity output increases by around one percent. The effect of rotor size is even more pronounced: doubling blade length quadruples energy yield. Because winds are stronger and more consistent at higher altitudes, modern turbines can also exploit their capacity much more effectively.

Installed capacity has likewise multiplied in recent years. Whereas the average turbine delivered around 1 MW in 2000, today turbines with capacities of around 5 MW or more are being installed. Higher full-load hours and more efficient use of wind resources significantly reduce generation costs. Wind energy is already among the most cost-effective forms of electricity generation, particularly onshore wind at good locations.

Optimized Wind Farm Layout: Fewer Turbines, Higher Output

As part of repowering projects, the number of turbines in a wind farm is reduced. A common rule of thumb illustrates the potential: halving the number of turbines can double installed capacity and triple electricity output. The available land is used more efficiently, and fewer turbines are required overall.

Older turbines are often scattered and located close to residential areas. Repowering therefore also offers an opportunity to reorganize turbine placement from a spatial planning perspective, helping to reduce the visual impact on the landscape.

Home Advantage: Cost Benefits and Faster Implementation

Repowering projects benefit from existing local acceptance of wind energy at established sites. Existing infrastructure—such as substations, cable routes, and access roads—can continue to be used. This saves costs and conserves resources, as significantly fewer construction measures are required.

Another advantage is that these sites are already designated for wind energy. Lengthy permitting procedures and extensive environmental impact assessments are largely avoided. This makes repowering a faster process and helps accelerate the energy transition.

More Powerful, Quieter, More Compatible

Modern wind turbines are significantly quieter than their predecessors. As rotor diameters increase, maximum rotational speeds decrease, resulting in smoother and quieter operation. Optimized blade aerodynamics further reduce noise emissions. In addition, demand-controlled night-time aviation lighting prevents continuous flashing at night.

Because modernized wind farms are built under current regulations, new projects comply with the latest standards in environmental and noise protection law. This also allows potential planning shortcomings from the past to be corrected.

Better Grid Integration and System Stability

State-of-the-art turbines can be integrated into the electricity grid far more effectively. Modern wind turbines are capable of providing system services such as reactive power and balancing power, are controllable, and contribute to grid stability. This represents an important contribution to future security of supply.

Decommissioning and Recycling: Responsible Handling of Old Turbines

As part of repowering, old turbines are completely dismantled, including the full removal of concrete foundations from the ground. After dismantling, turbines can in some cases be resold as complete units or used as sources of spare parts. Individual components such as rotor blades, gearboxes, or generators may find a second life.

What cannot be resold is professionally recycled. Around 90 percent of a wind turbine—including the tower, metal components, electrical systems, and foundations—can be materially recycled and reintroduced into the economic cycle as secondary raw materials.

Segments of steel and concrete hybrid towers are typically dismantled step by step. Towers and foundations are easy to recycle: concrete is crushed on site and reused in road and path construction, while steel from nacelles and tower segments is recycled in steel production.

Significant progress has also been made in recycling rotor blades. Fiber-reinforced plastics are now predominantly used in the cement industry: the synthetic resins provide energy for the energy-intensive kiln process, while the glass fibers replace natural raw materials such as sand. This process helps save fossil fuels and primary raw materials. At the same time, the wind industry is working intensively on new, more recyclable materials and processes to further improve the recyclability of rotor blades in the future.

Axpo Also Focuses on Repowering

Axpo is also leveraging the significant potential offered by repowering. In Harlingerode, Lower Saxony, for example, two wind turbines from 2001, including their foundations, were completely dismantled in 2025. Each of the two turbines, with a capacity of 1.5 MW, had supplied—on a purely statistical basis—around 900 average German four-person households with electricity each year over their operating lifetime. They are now being replaced by a modern wind turbine that can generate three times as much electricity, while halving the number of turbines. This project vividly demonstrates how proven sites can be made future-proof through modern technology.

Conclusion

Repowering is more than simply replacing old turbines with new ones. It is an intelligent approach to using wind energy more efficiently and accelerating the energy transition. Proven sites, modern technology, and responsible resource management make repowering a key element of a sustainable energy future.