Renewable Energy System Scoops Worldaware Award for Innovation
Design engineers, Ove Arup Zimbabwe, have won the Innovation category of the Worldaware Business Awards for the Vawtex (vertical axis wind turbine extractor) - a wind turbine able to rival electricity as a power source for ventilation.
The Worldaware Business Awards, now in their 14th year, recognise projects that have contributed to the development of poorer countries through innovative and sustainable commercial activities. The Worldaware Innovation Award goes to a project with the proven potential to make a significant contribution to socially, economically or environmentally sustainable development.
The cost of installing the Vawtex is similar to that for conventional ventilation. But it is much less noisy, has no fuel cost and causes no pollution. Interest is growing in ventilation without electricity. In some conditions, a building can cool and ventilate itself. Hot air rises in a room and, as it leaves at the top, draws in cool air at the bottom. This effect can be enhanced with a cowl mounted on the building. But even with a cowl it lacks power.
Arup decided that the solution was a wind turbine rotating on a vertical axis and driving a fan. Most wind turbines, for pumping water or generating power, rotate on a horizontal axis like a windmill; but they are usually sited in open country. They cannot easily follow the constantly changing wind directions caused by the buildings in a city. A turbine on a vertical axis, however, can.
In addition, the Vawtex is designed to take advantage of the wind's lift effect, which takes an aircraft off the ground. This additional force enables it to rotate three times as fast as if pushed by windspeed alone.
The Vawtex will rotate in winds less than 3mph but it is also designed to turn less and less efficiently as the wind becomes dangerously high. Zimbabwe has no tunnel for high-wind testing; so the Arup team tested their turbine by putting it on a pick-up truck and driving it at 75mph down a racetrack!
Mike Rainbow, Associate for Ove Arup, says his Harare colleagues with their knowledge of locally available materials made a crucial contribution to the Vawtex's efficient manufacture by tapping into their ingenuity and resourcefulness, honed by years of hard-currency shortages. A local undergraduate helped as part of his course. The project has sustained jobs in what is currently the fastest shrinking economy in the world.
The first Vawtex was built for a new arts block at Harare International School, where it helps to cool down the building during the day as well as taking the chill off winter mornings. Vawtexes have been installed at Africa University on the Mozambique border and at the Mediterranean Shipping Co's Zimbabwean HQ. In March, eight are due to be installed at the Centre for Sustainable Construction in Belgium. Arup believes the international market for such devices could easily number thousands per year.
"Developing this technology here over the last couple of years or so from concept to delivery has meant overcoming an array of obstacles under increasingly challenging circumstances. Results to date have more than compensated for difficulties met along the way and are a tribute to the determination and resourcefulness of all involved. The Award represents a fitting testimony to this combination of resilience and creativity and provides further encouragement for the next exciting stages of derivative product development," said Mike Rainbow.
For further information:
Worldaware: Helen Triggs 020 7603 8573/Sally Canty 02380283255
Ove Arup Zimbabwe: Mike Rainbow Tel: +263 4 882250