Over the years, scientists have been trying to capture tidal energy, which is abundant and renewable.  Nevertheless, how to do so effectively has been a challenge as it was suggested that 2 m/s may be the minimum tidal flows for economic power production. In other words, slower flow will not be considered as providing a viable option.

Fortunately, in 2015, a research team from City University of Hong Kong and Inha University of South Korea developed a new approach in extracting power from low tidal flows, which is using vertical arrays of reduced diameter turbines, and the required start-up velocity of tidal can be as low as 0.4 m/s. The result showed that a power increase of 40% could be obtained from a vertical array of reduced diameter turbines when compared to a single, large-diameter device with the same frontal area.

This may be the first turbine with start-up velocity as low as 0.4m/s! We trust the continued development of such technology will make capturing of tidal energy a viable option in Hong Kong.

More details can be found in A New Concept in Tidal Turbines published by Benjamin T. Tarver, Johnny C. L. Chan and Chul-H. Jo on International Journal of Energy Research.

The report is available for downloading at Wiley Online Library: http://onlinelibrary.wiley.com/doi/10.1002/er.3440/pdf.

Photo source:  A New Concept in Tidal Turbines published by Benjamin T. Tarver, Johnny C. L. Chan and Chul-H. Jo on International Journal of Energy Research