Model guide
Vestas V136
The large-rotor, low-to-medium-wind model of Vestas’ 4 MW platform: 136 m rotor, 66.7 m blades. The first common version was 3.45 MW, the later one 4.0–4.2 MW. In 2020 I worked on ground and nacelle assembly on a V136-3.45 MW project; the field notes on this page come from that job.
What defines this model
The energy a turbine captures grows linearly with swept area. The V136’s 14,527 m² is about 17% more than the V126 — on a weak-wind site that area is the biggest lever you have.
The price is paid in the blade: a 66.7 m blade is long, heavy and flexible. Root moment, blade-bearing load, transport and the crane plan all grow with it. The drivetrain follows the rest of the platform: a gearbox with two planetary and one helical stage and a full-scale converter.
Key technical data
| Parameter | Value |
|---|---|
| Rated power | 3.45 MW / 4.0–4.2 MW (by version) |
| Rotor diameter | 136 m |
| Swept area | 14,527 m² |
| Blade length | 66.7 m |
| Hub height (4.2 MW) | 105 / 112 / 117 / 149 / 166 m |
| Cut-in | 3 m/s |
| Cut-out (4.2 MW) | 25 m/s |
| Wind class (4.2 MW) | IEC IIB / IEC S |
| Gearbox | 2 planetary + 1 helical stage |
| Converter | Full scale |
| Power regulation | Pitch regulated, variable speed |
Drivetrain and systems
Blade and blade bearing
- On a long blade the pre-tension of root bolts and blade-bearing lubrication head the periodic work.
- Even a few degrees of pitch difference between blades comes back as rotor imbalance and vibration; the physical angle is compared with the encoder value.
Assembly
- Nacelle and blade lift windows are very sensitive to wind limits; it is usually the hours spent waiting on wind, not the mechanical work, that sets the assembly schedule.
- Torque and tensioning sequences on flange and root connections follow the documentation and are marked; later checks rely on those marks.
Full-scale converter and cooling
- All the power passes through the converter; its liquid cooling circuit and power connections are critical maintenance items.
V126 and V136 (Vestas)
| Item | V126-3.45 MW | V136-4.2 MW |
|---|---|---|
| Rotor diameter | 126 m | 136 m |
| Swept area | 12,469 m² | 14,527 m² |
| Blade length | — | 66.7 m |
| Converter | Full scale | Full scale |
Maintenance topics that matter in the field
- On a vibration complaint, verify the pitch angles physically first; look at calibration before blaming the blade.
- Blade-to-tower clearance and blade surface: periodic visual checks matter more on a long blade.
- Converter and gearbox coolers: on a dusty site, radiator cleaning is one of the highest-return jobs.
Sources
Warning: Every job in the nacelle, hub and tower follows lockout–tagout (LOTO), rotor lock and the manufacturer’s safety instructions. This page is field experience and published data; it does not replace the service documentation.