Small wind turbine FAQ

A 1 kW turbine produces about 2,000 kWh a year at a 5 m/s average wind speed, 1,100 kWh at 4 m/s and 3,000 kWh at 6 m/s. Rated power is only reached at 11 m/s — the annual mean wind speed at hub height is the number that decides your output.

At least 4.5 m/s annual average at hub height for a grid-tied system to pay back within its lifetime, and 5 m/s or more for a good return. Below 4 m/s, solar is almost always the better investment.

The hub should clear the nearest obstacle by 10 m. Practically: 9–12 m on open land, 15 m next to trees or single-storey buildings, 18–24 m for 5 kW and above. Height buys more energy than a bigger rotor.

48–55 dB(A) at 10 m depending on model, which is quieter than a normal conversation. Most jurisdictions allow 45 dB(A) at the nearest dwelling at night, so site the tower at least 40 m from a neighbour.

20 years design life for the structure and generator; blades typically need replacement or refurbishment at 10–12 years; bearings at 8–10 years; the controller at 8–12 years. Annual servicing is what separates a 20-year machine from a 6-year one.

One service visit a year: blade bolt torque, blade condition, yaw bearing play, guy wire tension, brake test, controller log review. Budget 1–1.5 % of the capital cost per year.

Yes, with a certified grid-tie inverter that includes anti-islanding protection. In most countries the connection must be installed and commissioned by a licensed electrician and approved by the utility before it is energised.

Only if you are off-grid or want backup. A grid-tied turbine without storage is cheaper, simpler and has fewer failure points. An off-grid system needs 2–3 days of autonomy, which usually costs more than the turbine.

Turbine head only: USD 700 (300 W) to 15,000 (10 kW). A complete installed 3 kW off-grid system with tower, controller, battery and installation: USD 9,000–14,000. A 5 kW grid-tie system: USD 12,000–18,000 before shipping and civil works.

Yes, and it should be in most climates. Wind and solar share one DC bus through a hybrid controller; the combination needs 30–40 % less battery than either source alone and cuts generator hours by 85–95 %.

Poorly. Buildings create turbulence that both reduces mean wind speed and fatigues the turbine. Rooftop installations produce 30–50 % of the free-stream estimate unless the roof is more than twice the height of surrounding buildings.

Standard models ship in 15–25 days ex-works. Installation of a 1–5 kW machine takes two to three days with two people; a 10 kW machine needs a crane and about a week on site.