Winds of change in clean energy in Singapore

JTC, HDB looking into use of turbines to harvest waste air flow to generate electricity
Victoria Vaughan Straits Times 3 Sep 10;

WIND may still be used to generate electricity in Singapore - just not Mother Nature's breeze.

Both JTC Corporation and the Housing Board are looking into the use of vertical axis wind turbines, where the blades spin around an upright shaft.

JTC has put out a tender for two such wind turbines to harvest waste air flow from lift exhausts - openings on the roof to ensure ventilation for lift shafts - at its CleanTech One building at CleanTech Park, currently under construction near Nanyang Technological University.

Contractors are yet to be confirmed, however, and the project is considered 'highly experimental', according to a spokesman.

HDB is also looking to test out the feasibility of wind energy and has purchased a 200-watt vertical axis wind turbine - just powerful enough to light up a bedroom, for example. It is currently looking at possible locations for testing the device using both natural and generated wind.

One manufacturer is hoping this will be the start of harnessing the potential of wind generated from cooling towers, lift shafts and bathroom ventilation systems, which populate the roofs of major buildings in Singapore and throughout the region.

Mr Ong Gin Keat, chief executive of Singapore company CygnusPower, which makes these turbines, said: 'Air is coming out of (air-conditioning) chillers for 10 to 12 hours a day at shopping centres and office blocks, and for 24 hours at industry sites.

'Our turbines can recover between 20 and 30 per cent of the power from a cooling tower, which will be fed back into the building and cut down on operating costs. It's not a big wind from the North Sea but if they were on all big buildings, it could mean at least a 20 per cent recoup of electricity for Singapore,' said Mr Ong, who has partners in Japan and South Korea.

For a 1 kilowatt (kw) turbine, costing about $12,500, this could mean savings of about $57 a day for buildings operating for 12 hours, and $20,805 annually. There are also environmental benefits as a

1 kilowatt-hour unit working at 20 per cent can save nearly a tonne of carbon dioxide a year.

Nanyang Polytechnic (NYP) bought a 2kw vertical axis turbine last November, which is now plugged into the grid and awaiting approval from Singapore Power - expected later this month.

Mr Chan Yew Meng, senior director at NYP's school of engineering, said: 'We have been using natural wind to power the turbine. Using scavenged wind from exhausts is an interesting concept... We are going to do research in that area. We are also looking at the best way to harvest wind, whether from one big turbine or a cluster of smaller ones.'

Singapore Polytechnic's Dr Jiang Fan, manager of the Technology Centre of Energy Conservation, however, is not convinced that using salvaged wind to drive turbines will have an effect on energy efficiency.

'If you put a wind turbine in front of an air-conditioning exhaust fan, you block the air flow. But you want to keep the air flow speed the same to maintain the temperature level, so you may have to increase the power to the air-conditioning to drive the turbine,' he said, adding that he did not have any data to prove this theory, so it was still worth researching further.