Windy ways
AFTER developing an unusual wind turbine with no external blades, Sambrabec Inc., in Canada is all set to develop a new scaled up version. The much acclaimed Catavent 500 w self-regulating, ducted wind turbine developed by Louis Beaulieu, is being scaled up to 150 KW which could mean a significant advantage over conventional horizontal and vertical axis wind turbines. (Wind Power Monthly; Vol 11, No 7).
The Catavent 500 consists of 2 modular turbines able to operate at varying wind speeds, from about 5 kilometres per hour (KPH) to 150 KPH, producing 500 W at 1000 revolutions per minute (RPM) at an average wind speed of 32 kph. With a diameter of 1.2 metre, this wind turbine is built in plastic and aluminium, the same materials used in the scaled up prototype. However, the 150 Kw type would comprise a single turbine with a diameter of about 18 metres and with power electronics. Being modular and transportable in 4 pieces, this new version would be easily disassembled and assembled.
Operating with minimal noise and turbulence, the Catavent is driven by air entering its internal vanes. Because of a high wind energy capture efficiency, the Catavent can capture more than 50 per cent of the energy content of the wind, which is considerably more than the 27 per cent quoted for traditional wind turbines. Moreover, it requires closer spacing on wind farms than conventional turbines, thus,saving land. The turbine could be mounted on multiple sup- ports, or possibly even placed atop one another, as with Catavent 500.
Engineers at Sambrabec see Catavent 150 Kw as highly appropriate for industrial power supply applications. Besides, the Catavent would suit small wind farms since it requires no expensive transmission system. While the Canadian Hydro Quebec has agreed to buy electricity from a I mw grid connected wind farm made up of 8 Catavent 150 KW units, to be built on the Gaspe Peninsula in late 1996, the reliability and power quality of this novel design is being debated. While some experts are critical about this Catavent for its unproven performance and data uncertainities, Beaulieu and his supporters believe that "the scale up to 150 Kw will be commercially viable and will replicate the excellent energy capture of the Catavent 500."