Blog
How long does a small wind turbine last?
The structure is good for 20 years. The blades are good for 10–12. The controller is good for 8–12. Whether the machine reaches year twenty is decided by whether anyone services it in year three.
Component life, honestly
| Component | Expected life | Replacement cost |
|---|---|---|
| Blades | 10–12 years (leading-edge erosion) | 15–20 % of unit price |
| Main bearings | 8–10 years | 5–8 % |
| Generator windings | 20+ years | 25–30 % if rewound |
| Controller / inverter | 8–12 years | 10–15 % |
| Tower and foundation | 25–30 years | — |
| Battery bank (off-grid) | 8–12 years (LFP) | 30–50 % of system |
The annual service, item by item
Blade bolt torque to the manufacturer's figure; blade leading edge inspected for erosion and cracks; yaw bearing play checked by hand; guy wire tension measured; brake tested from the controller and from the manual switch; slip ring inspected on 5 kW and above; controller log downloaded and reviewed for overspeed or over-temperature events.
Two hours for a 1–3 kW tilt-up machine, half a day for a 10 kW tower. Cost: USD 150–300 plus parts.
The five failures we see most
One: blades destroyed by overspeed because the furling hinge seized — a five-minute lubrication task skipped for three years. Two: controller dead after a lightning strike, because the surge arrestor was never installed. Three: cable corroded at the tower base because the drip loop was missing. Four: battery bank sulphated from chronic undercharging. Five: tower guys slack, leading to fatigue cracks at the base weld.
None of these are manufacturing defects. All five are installation or maintenance decisions.
Refurbishment versus replacement
At year 10, a typical 3 kW machine needs blades, bearings and maybe a controller — roughly 30 % of its original price. At year 15, compare that with a new machine that is 15 % more efficient and carries a fresh warranty. For most operators the answer is refurbish at 10, replace at 18.
