Terje Lade, Vindskip project manager, writes for Splash today.
Wind propulsion systems, when it comes to installations, are already outpacing installations of low carbon alternative fuels. According to IWSA, there are already 11 large ocean-going vessels with wind-assist systems installed and a further 20+ smaller vessels using wind; which is more than all current new alternative fuelled vessels combined.
This is exciting news, and it’s led to exciting predictions. Writing in Splash247 a few months ago, Gavin Allwright of IWSA argued that wind propulsion could end up not only paying for itself, but funding further decarbonisation investment in low and zero carbon fuels.
Eleven vessels, however, is still a drop in the ocean compared to the 62,100 vessels in the global merchant fleet. The adoption of wind propulsion, as with many other cleantech solutions, needs to see exponential growth if it’s going to start to make a dent in shipping’s carbon footprint. Theoretical predictions of savings are one thing, but we can’t afford for wind propulsion to become shipping’s version of nuclear fusion – a game-changing technology that is perpetually 30 years away.
For the engineers and designers working on wind propulsion, the magic formula requires balancing out the speed of the vessel and the fuel consumption – and the savings that can be derived from reducing this consumption. As the real-life application and the commercial viability of wind propulsion come hand in hand, credentials such as regularity and punctuality must be carefully considered.
This balance is crucial and has been previously studied by sailassisted vessel design firms such as Knud E Hansen, which concluded that the fuel savings at 11 knots were 16.5%, while at 13 knots they were only 9% because the vessel still needed to use engine power to get enough propulsion for that level of speed. The findings resulting from the analysis of this ratio show that for routes with bad winds – such as a route from Korea or China to Europe – fuel savings could even be negative. As such, wind propulsion systems rely very heavily on optimal integration with the engine and the other elements of the vessel to ensure fuel efficiency and route optimisation.
The kind of cargo transported by the vessel also plays a key role in the viability of wind propulsion systems onboard. Wind propulsion works well for routes where speed plays a small role, such as those from Brazil to China transporting iron ore. However, on shipping services where higher speed is essential (minimum 14 knots), sail-assisted ships have proven to not be an efficient option. This is the case with routes that involve the maritime transportation of vehicles across the Atlantic, for example.
Commercial success in this respect depends heavily on weather routing, which includes considerations of favourable wind angles in the route planning. Modelling using weather routing helps engineerinig and design teams to understand that neglecting the hydrodynamic response to the aerodynamic forces can cause significant errors in the prediction of the propulsion power demand and the corresponding fuel consumption. This is the reason why realising wind propulsion’s full potential will not only involve weather routing but will also require sophisticated automation and system integration expertise
Wind propulsed ships also represent an operational challenge for crews that are used to conventionally powered ships. Turning this weather information into operational data, and using it to make commercial wind propulsion a reality, places specific demands on a vessels’ automation systems. Automation here does not necessarily mean autonomous vessels, but refers to the fact that almost every system on board relies on some level of automated control. Integrating wind propulsion data and weather data into the propulsion, stability and navigation systems of a vessel increases the amount of data that needs to be shared throughout a ship, and the number of systems that utilise it.
This in turn requires shipping to improve its standard of automation – how information is shared between different systems on board a vessel. Currently, automation is one of the lowest cost items for any vessel or project. Compared to the cost of hardware, automation systems are generally low cost, and not subject to the same scrutiny. Because of this, ship yards, naval architects and owners frequently simply rely on automation systems that are bundled with hardware or simply select the cheapest option on offer. This can lead to a range of inefficiencies in how different systems relate and talk to each other, which could be alleviated if owners and yards specified parameters for automation systems at the outset of a project. However, this only happens rarely. Yards, owners, companies, designers and system providers therefore will need to become accustomed to discussing automation at the outset of any project, rather than leaving it as an afterthought.
All vessels can and should benefit from wind propulsion. But for the first movers, we need to make it as easy as possible, and this needs to work in line with commercial incentives. Wide consideration and adoption will only be possible if commercial viability is achieved through optimal levels of efficiency, regularity and punctuality. This will require the shipping industry to understand that systems integration work is the key enabler of wind propulsion, and that therefore it must raise its expectations and standards of automation.