Turbine Classes in Repowering

Which legacy turbines are currently being replaced by which modern platforms? Three generations define the German fleet: pioneer turbines from 1996–2002, the 2 MW class from 2002–2010, and the first multi-MW turbines from 2010 onward. Replacement turbines are typically one size category up.

Typical Legacy Turbines in the German Fleet

Modern Repowering Turbines 2026

Typical Repowering Configurations

Why So Much More Yield?

Three levers multiply the energy output:

1. Hub height: wind speed increases with height (logarithmic wind profile). From 67 m to 165 m means approximately 25–35% more wind speed at the rotor
2. Rotor swept area: energy capture increases with the square of the diameter. From 66 m to 162 m = 6× more rotor area
3. Turbine efficiency: modern aerodynamics, lower specific power rating, improved generator efficiency — 10–15% more efficiency overall

Turbine Classes per IEC 61400-1

• Class I: high-wind sites (v ≥ 10 m/s at hub height) — coastal locations, ridge tops
• Class II: medium wind (8.5–10 m/s) — northern Germany, open inland sites
• Class III: low wind (7.5–8.5 m/s) — low mountain ranges, southern inland areas
• Class S: site-specific — custom adaptation for extreme conditions

Turbine class comparison — yield multipliers and IEC wind classes

Low-Wind Turbines for Southern Sites

Southern Germany and low-wind inland sites require low-wind turbines with large rotors paired with smaller generators:

• Vestas V162-5.0 / V172-5.0 (5 MW with 162/172 m rotor)
• Enercon E160 EP3 (4.6 MW with 160 m rotor)
• Nordex N163/5.X (5.6 MW with 163 m rotor)

These achieve rated output frequently even at 5.5–6.5 m/s mean wind speed and accumulate high full-load hours.

Bigger Rotors, Bigger Setbacks

The jump from a 66 m rotor to a 175 m rotor changes not only the yield but every emissions-relevant parameter that permitting depends on. The sound power level of modern turbines typically runs 104–106 dB(A); permitting follows the TA Lärm noise limits (around 45 dB(A) at night in purely residential zones, 40 dB(A) in designated health-resort areas). Shadow flicker assessments apply the LAI guidance thresholds of 30 hours of astronomically possible and 8 hours of real shadow per year as the shutdown trigger. Taller hub heights also extend the ice-throw radius and increase the visibility of night-time obstruction lighting. In practice, this means that in densely populated areas the turbine that gets permitted is not the highest-yield one but the one that best fits within these emission limits. The relevant expert studies are covered in the expert reports overview.

Logistics: Cranes, Access Roads, and Transport

Turbines in the 6 MW class, with individual blades over 80 m long, place heavy demands on site access. Erecting them requires crawler cranes rated well above 700 t and crane pad areas covering several thousand square meters. Access roads built in the 2000s are often too narrow in curve radius for the long blade transports and need to be upgraded. These earthworks and logistics costs are routinely underestimated in project calculations and should be assessed early in the site evaluation — particularly for hilltop and forest locations with steep approach routes.

Legal Limits on Turbine Height

Not every technically available turbine type is permissible at every site. The main constraints are: height restrictions in municipal land-use and zoning plans, aviation safety zones around airfields (§ 12 LuftVG), VOR navigation beacons and weather radar (setback recommendations from Germany's air navigation service DFS and weather service DWD), and the general obligation to take neighboring residential use into account. In Bavaria, the former 10H setback rule continues to delay many projects even though it was relaxed in 2023. Land-use classification in undeveloped outlying areas is covered on the § 35 BauGB page, and the overall approval procedure on BImSchG procedure.

Frequently Asked Questions

Which manufacturer dominates German repowering in 2026?

Estimated market shares in the 2024–2026 repowering wave: Vestas approx. 35%, Enercon approx. 25%, Nordex approx. 20%, Siemens Gamesa approx. 15%, GE approx. 5%. Local manufacturer presence and service conditions typically matter more than the turbine platform alone.

How do the new 175 m rotors affect permitting?

Larger turbines require larger setback distances due to noise, shadow flicker, and ice throw. In densely populated areas, turbine selection becomes a limiting factor — a smaller E160 with reduced throw distance may be permissible where a 6 MW V172 would not pass approval.

What does a modern 6 MW turbine cost?

Typical turnkey investment: 6–8 million EUR per turbine (as of 2026), including foundation, grid connection, and road construction. Without site development, from 4.5 million EUR.

Is it worth waiting for an even bigger turbine class in a few years?

This trade-off mainly comes up at sites with long-term secured land availability. Since every repowering permit has to go through the full BImSchG process again regardless of turbine size, "waiting for the next turbine generation" is rarely economical — the lost yield from the unused standstill period typically outweighs the gain from a larger turbine by a wide margin. It is usually more sensible to plan with the turbine class that is currently available and permissible at the site, and only consider a further repowering once the new turbine has reached the end of its technical service life.