The Catavent is a ducted turbine driven by air entering its internal vanes. Details of the machine are not available due to patent considerations, but it is said to operate with minimal noise and turbulence. The Catavent 500 consists of two modular turbines able to operate from about 5 kph to 150 kph, producing 500 W at 1000 RPM at an average wind speed of 32 kph. It produces electricity at C$0.083-0.122/kWh (US$0.061-$0.089/kWh). The wind turbine's diameter is 1.2 metre and it is built in plastic and aluminium, which are also used in the scaled-up prototype. Some 100 units of the Catavent 500 have been sold worldwide, several of which have operated for more than eight continuous years. Sambrabec was founded in 1984 and is based in the Montreal suburb of Ville St-Laurent in Quebec.
Beaulieu maintains that the Catavent can capture more than 50% of the energy content of the wind, considerably more than the 27% quoted for traditional wind turbines. Field testing by Sambrabec over several years confirms this claim, he says. Such a high wind energy capture efficiency, if duplicated on the scaled-up prototype, could potentially constitute a significant market advantage over conventional horizontal and vertical axis wind turbines.
Beaulieu says the 150 kW prototype would comprise a single turbine with a diameter of about 18 metres and with power electronics. Wind tunnel testing of an intermediate prototype rated between 500 W and 150 kW is due to begin shortly at the University of Sherbrooke. The 150 kW prototype could then be installed at a field test site outside Montreal on the north shore of the St Lawrence River. Beaulieu hopes it will produce power at C$0.061/kWh (US$0.045/kWh) or less.
The 1 MW wind farm could be built in late 1996 and start in early 1997 to exploit strong and reliable winter winds, adds Beaulieu. The eventual contract with Hydro Quebec would likely feature both energy and capacity payments. Hydro Quebec is assessing the potential impact of the novel design on the reliability and power quality of the grid. Meantime, Sambrabec has a joint venture with Brazilian partners, concluded in 1992, and is considering strategic alliances with Canadian firms. The 150 kW version would be modular and transportable in four pieces, easily disassembled and assembled. It would be manufactured at Sambrabec and customers would need an assembly facility.
Beaulieu sees the large turbine as highly appropriate for industrial power supply applications. Moreover, the Catavent would suit small wind farms which could fully demonstrate the high intrinsic value of distributed, low voltage electricity, which requires no expensive transmission system. The highly efficient and minimally turbulent Catavent would allow much closer spacing on wind farms than conventional turbines, with significant savings in land area. The turbines could be mounted on multiple supports, or possibly even placed atop one another, as with the Catavent 500.
The Catavent has been criticised by several Canadian experts for its unproven performance and data uncertainties. However, Beaulieu believes that the scale up to 150 kW will be commercially viable and will replicate the excellent energy capture of the Catavent 500. "Still larger Catavent scale-ups above 150 kW are under consideration," he adds. Scale-ups of this order are clearly fraught with technological uncertainty. However, if the project achieves high efficiency, reliability and cost competitiveness with other wind turbines, the large Catavent could become a major player in the world wind industry.