Windpower has been with us for millennia. Our ancestors used it to power vessels to sail the River Nile around 3400 BCE and the seven seas ever since. Now. A modern tack sees US scientists developing a “wingsail” to assist with the propulsion of an otherwise diesel-powered vessel that might be used as a ferry. They outline their plans in the International Journal of Environmental Technology and Management.
Timothy Lipman and Jeffrey Lidicker of the Transportation Sustainability Research Center at the University of California at Berkeley, USA, explain how a carbon-fibre, computer-controlled wingsail could be mounted on a 14-metre trimaran test vessel, which was then sailed through San Francisco Bay over a three-month test period.
The project demonstrated that for the test vessel sailing at seven knots on a given ferry route, wind of between 10 and 20 knots was sufficient to save between 25 and 40% of the fuel that would otherwise be burned running the vessel’s engines; also assuming no seriously adverse effects of currents. This the team says not only makes sense economically but also could be useful in reducing carbon emissions and pollution from such vessels. The real-world benefits might be somewhat different given that the Bay ferryboat services operate at 17 or more knots, but the proof of concept is encouraging and could provide the basis for further investigations and optimisation of the system for ferries.
Lipman, T.E. and Lidicker, J. (2019) ‘Wind-assist marine demonstration for ferries: prospects for saving diesel fuel with wind power’, Int. J. Environmental Technology and Management, Vol. 22, No. 1, pp.68–83.