Turbine type · VAWT

Vertical axis small wind turbine

No yaw, no tail, no furling. A vertical axis rotor takes wind from any direction, which is why it survives roofs, ridges and coastlines where the wind changes quarter every few seconds.

Our vertical machines use a Darrieus-H rotor: three straight blades on two arms, mounted on a vertical shaft with the generator at the base. Wind from any direction produces torque, so there is no yaw system to wear out and no tail to fold in a gust.

The honest limitation is efficiency: a VAWT extracts 20–35 % less energy per square metre than a good HAWT, because half the rotor is always working in the wake of the other half. It wins where the wind is turbulent, the mounting height is limited, or noise and vibration rules out a spinning three-blade rotor.

Model	Rotor	Output (5 m/s)	Ex-works	Typical use
WT-V300	1.1 m	550 kWh	USD 890 – 1,150	Lighting, CCTV, signage
WT-V1000	1.8 m	1,800 kWh	USD 2,300 – 2,900	Rooftop PV hybrid
WT-V3000	2.6 m	5,200 kWh	USD 5,400 – 6,900	Campuses, warehouses

Vertical axis turbines are the wrong purchase in three situations, and it is worth saying so plainly. First, any open site with a clear prevailing wind: a horizontal axis machine of the same swept area will out-produce it by a quarter and cost less per kWh. Second, any site where you can build a 15 m tower — height solves turbulence better than rotor geometry does. Third, any buyer shopping on price per kW: the extra rotor area a VAWT needs to compensate for its lower efficiency makes it the more expensive machine per unit of energy.

Where it does earn its price is specific: a listed building where a visible three-blade rotor would be refused, a coastal site with reversing winds, a roof with a 3 m parapet limit and no space for guys, or a location where the tonal noise of a HAWT gearbox would generate complaints. In those cases the alternative is not a cheaper turbine — it is no turbine at all.

Compare at a glance

Criterion	Advantage	Practical meaning
Directional sensitivity	None — accepts wind from 360°	Right choice for gusty, changeable sites
Efficiency	20–35 % lower than HAWT	Compensate with a larger rotor
Noise and vibration	Lowest of the three types	Suitable for rooftops and near buildings
Self-starting	Needs a small Savonius starter or a low-cut-in generator	Our H-rotors start at 2.8 m/s

Models in this family

Frequently asked questions

Are vertical axis turbines better for rooftops?

They are better where the wind is turbulent and directions change constantly, which describes most rooftops. But rooftop wind is generally poor: buildings create eddies and the mean speed at 3 m above a roof is often half the free-stream value. If you can get 10 m of clear height, a horizontal axis machine will out-produce a VAWT of the same swept area.

Do VAWTs need a tower?

They need less height, but not none. A 2 m rotor on a 4 m mast clears the recirculation zone better than one bolted to a parapet. We supply roof frames and guyed masts for both.

How do they handle storms?

The rotor cannot furl, so protection is electrical: the controller brakes the generator and dumps surplus into a resistor bank. Our 3 kW unit is rated to 50 m/s survival.

How much does a vertical axis wind turbine cost?

USD 890–1,150 for a 300 W unit, USD 2,300–2,900 for 1 kW and USD 5,400–6,900 for 3 kW, ex-works with controller. Add USD 400–1,500 for a roof frame or guyed mast.

Is a VAWT better than solar on a roof?

For most roofs, no. A 3 kW PV array on the same roof produces two to four times the energy of a 1 kW VAWT for similar money, and needs no maintenance. A VAWT earns its place only where wind blows when the sun does not — high latitude, winter-peaking loads, coastal sites.

Vertical axis small wind turbine

Compare at a glance

Models in this family

Frequently asked questions

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