The V3.5 VAWT has three major components (turbine, generator and inverter) that offer a series of features which have been customized as a fully integrated offering by Cleanfield Energy™. This solution enables the complete system to be optimized for maximum efficiency and reliability.



Cleanfield’s turbine has been designed for simplicity by having fewer moving parts and providing increased reliability while the stationary center structure can accommodate grounding for lightning protection.

The turbine was designed with a high aspect ratio in order to accommodate low nominal RPM of the turbine. As a result, a low blade speed ratio (ratio of blade speed to wind speed) minimizes audible noise.

The blades are connected to the shaft by way of a pair of struts with an aerodynamic profile that has very low power losses, contributing to a better power coefficient of the turbine.

The turbine is equipped with a custom developed sensor/communication interface board which communicates with the inverter for data collection, supervision and protection of the turbine resulting in extended life expectancy and lowering maintenance costs. The sensor board monitors turbine vibration for resonant frequency skipping or to shutdown turbine if excessive vibration is detected; generator temperature to reduce the output power of the turbine and eventually shut it down if thermal operating limits are approaching; ambient temperature to prevent the turbine start if outside temperature drops below -40C and prevent the bearing from damage; and electromechanical brake status to ensure controlled stoppage of turbine and control turbine speed to ensure that turbine is operated within safety limits and maximized efficiency.



The generator is a direct drive, low speed, permanent magnet generator (PMG) with an external rotor. Designed and built to match the turbine parameters (nominal rotational speed, nominal torque, assembly requirements etc.), it is an integral part of the system structure.

The Fail-safe Electro-mechanical brake with status feedback is included in the generator (energized in order to be released) and will engage in case of power loss. Shutting down the power will stop the turbine from spinning and also allows service and maintenance work to proceed safely.



The inverter has been designed with a custom algorithm for permanent magnet generator control. The flux vector control software provides an extremely sophisticated means of monitoring voltage, frequency, and current without costly and unreliable external sensors which is capable of profiling and predicting patterns and conditions.

The V3.5 RPM is custom controlled by regulating current to and from the generator. The control algorithm allows variable speed operation and the generator delivers the optimum power by following the power curve of the turbine while staying within safety limits. As a result, even in high wind or gusty conditions, the turbine RPM will not exceed 160 RPM. This control algorithm is fundamentally different than virtually all other small wind turbines available today, and is of significant advantage, providing improved performance and margins of safety.


Offsite monitoring by Cleanfield is available via Ethernet internet connection for a preventative maintenance program. Options are available to modify the interface to directly interface to a Building Management Systems (BMS).



Cleanfield’s V3.5 VAWT has gone through extensive product engineering, testing (lab and field) and validation.

The following has been performed during product development and validation:

• Wind tunnel testing to validate product performance. Extensive testing has been performed by McMaster University at the University of Waterloo’s wind tunnel, University of Western Ontario’s Wind Tunnel Laboratory and at the National Research Council wind tunnel in Ottawa.

Wind tunnel testing at National Research Council, Ottawa

• Finite Element Analysis (FEA) of mechanical elements for static and fatigue analysis
• Structural cyclic fatigue testing of turbine shaft
• Structural testing of blades
• Inverter & generator tested and certified to CSA 22.2 No. 107.1-01

The V3.5 can be either directly roof mounted or ground mounted. The Cleanfield V3.5 has been designed to mount directly onto existing and new-built commercial rooftop structures allowing for renewable energy generation in unused rooftop space, and for architectural enhancements to new and existing structures for environmentally “greening” of buildings.

Cleanfield has pre-engineered rooftop mounts available for flat roofs and ground mount monopoles. All installations will require engineering review.



An increasing number of progressive organizations are adopting VAWTs because they are suitable for the characteristically turbulent and moderate winds in urban settings and they operate quietly. VAWTs can feed excess electricity into the local grid, which can further reduce the owner’s energy consumption costs. The use of VAWTs to produce distributed energy also reduces both the need for long-distance electricity transmission and fossil-fuel-fired emissions that contribute to climate change, and it provides points for LEED certification.

Wind flow within urban and suburban environments is turbulent and veering. The influences of nearby buildings, trees and other obstacles significantly alter wind flow patterns. Increased turbulence levels yield greater fluctuations in the wind speed and direction. Urban turbine installations offer numerous benefits, including local energy production (thereby reducing the need for utility investments in towers and transmission lines), as well as increased wind speeds over and around buildings producing a higher power generation potential.

Unlike a traditional horizontal axis wind turbine (HAWT), a VAWT rotates around the shaft vertically. VAWTs provide good performance in urban and suburban environments due to their inherent design characteristics. Some key benefits of VAWTs over horizontal wind turbines are:

• Ability to effectively capture turbulent winds which are typical in urban settings, especially in built-up areas; VAWTs do not need a yaw mechanism to face the blade rotor into veering wind directions. They immediately capture wind from any direction;
• VAWTs also typically operate at lower rotational speeds, thereby reducing or eliminating turbine vibrations and noise; and
• They are much more durable and reliable working in turbulent winds, as they are designed to harness wind forces from all directions.

Cleanfield’s V3.5 is particularly well designed to effectively capture erratic wind, mounted on either a rooftop or pole or integrated into building designs. The company has virtually eliminated vibration through customized operating software that also optimizes efficiency, reliability and life expectancy. Cleanfield’s proprietary inverter and sensor board are engineered with safety and performance enhancing features such as monitoring of vibration, generator and ambient temperatures, over-speed protection, and optimization of aspect and tip speed ratios and power coefficient.

• Our V3.5 VAWT has been specifically designed, tested and certified to effectively capture wind off of either rooftops or ground mount monopoles in urban, suburban and rural settings;
• Cleanfield’s VAWTs do not need to be raised high above the rooftop to operate effectively. They provide an excellent wind energy solution where there are height restrictions set by local regulations;
• Our V3.5 turbine, generator and inverter have been designed as an integrated system resulting in optimized system performance;
• The V3.5 operates at a broad range of variable rotor speeds;
• Its elegant design is simple and robust, resulting in long life expectancy and minimal maintenance;
• Low nominal RPMs result in lower blade speed ratio and negligible audible noise;
• Our unique sensor board has been integrated into the turbine for data collection and monitoring to control and protect the turbine;
• The advanced emergency braking mechanism manages turbine speed and locks down the turbine when wind speeds are excessive;
• Our turbine blades are made from gel-coated reinforced fibreglass, which minimizes icing conditions in the winter; and,
• We offer offsite monitoring as an option via a web-enabled connection for preventative maintenance.