Wind Propulsion (WP) & Wind Assist Shipping Projects (WASP)
The use of wind propulsion in modern commercial shipping covers a wide spectrum – from wind-assisted motor vessels, where auxiliary propulsion is provided by wind to primary wind ships with auxiliary engines, where primary propulsion is from the wind, augmented by engines to ensure just-in-time schedules are maintained .
Motor Vessels – The standard vessels that make up the vast majority of the current world fleet of ocean going vessels. Improvements in efficiency and savings in fuel costs and emissions have been achieved by increasing the size of vessels, improving hull design, increased engine efficiency and other modifications and to a limited extent by the use of renewable energy options for ancillary power. Operational changes have also been made, especially slow steaming, with reductions in speed to c.18knots and super slow steaming (14-16 knots). This slow steaming approach is especially effective for bulk cargos being delivered without tight time constraints, however slow steaming is less attractive when oil (bunker prices) drop.
Wind-Assisted Motor Vessels – primarily employing auxiliary-wind propulsion systems retrofitted onto existing vessels. These systems offer fuel savings in the 10-30% range, with lower initial retro-fit investment costs than new build options. The addition of these systems can also have other benefits such as reduced engine and machinery wear and tear, improved stability, reduction in vibration etc.)
Hybrid Wind/Motor Vessels – these designs combine fuel and emissions reduction benefits of wind propulsion options with the capabilities and performance of motor vessels allowing predictable scheduling. In favorable winds savings can be in excess of 60-70%, in less accommodating conditions vessels use a mix of wind/motor propulsion or motor alone. With good weather routing and handling, new build sailing hybrid vessels are defined as offering fuel savings on an annual basis of over 50%.
Purely Wind Vessel (+Auxiliary Motor) – these vessels can deliver up to 100% savings, with standard maintenance costs etc. however the challenge of maintaining schedules and being susceptible to weather conditions is an important consideration. Some routes will obviously be more favourable to this type of vessel and operation.
Weather Routing – The development of increasingly reliable weather/wind routing software helps to both predict, plan and operationally adjust sailing routes to maximize the benefits from wind and minimize the disruption from adverse weather conditions.