Wind power for shipping: not just hot air

Shipping is entering a brave new era with ever accelerating advances in big data, artificial intelligence, smart ships, robotics and automation. However, one of the newest and most exciting advances in cargo shipping is actually not an "advance" at all - but the adaptation of existing ideas that have actually been around for a very long time. Vessel propulsion mechanisms that innovators in shipping and maritime are testing right now are actually updated versions of tech that has existed for some time, such as that “rotor ship” described in that 1930 Popular Science article.

The main difference now is that wind propulsion for commercial vessels is gaining mainstream industry support (and may even be commonplace someday). For example, Norsepower has just begun a collaboration with Maersk Tankers, Royal Dutch Shell Shipping & Maritime, and The Energy Technologies Institute to “install and trial Flettner rotor sails aboard a Maersk Tankers-owned vessel”. Why is this age-old idea of wind powered commercial vessels being rediscovered now? And how exactly will wind propulsion in the 21st century be different from the sailing ships of old? I sat down with Gavin Allwright of the International Windship Association and Diane Gilpin of the Smart Green Shipping Alliance to find the answers.

Leah Kinthaert: Ms. Gilpin, you have previously mentioned there were "15,000 ships in the global fleet suitable for wind propulsion” can you tell me what that means – why are some ships in particular suitable and what sort of changes would need to be made to those ships?

Diane Gilpin: The 15,000 number relates to ships in the global fleet that may be suitable for wind. That is dry bulkers, tankers and general cargo vessels with clear deck space operating in windy regions. University College London did the original calculation estimating about 10,000 suitable small/medium sized ships that could be most advantaged by using wind devices - the smaller the vessel the greater the proportion of propulsion can be delivered by wind. Wind is free and so the more you can harness to propel your ship the more predictable your fuel costs become, which can underpin a new business model. The larger ships that may be suitable for retrofit are also same ship types - dry/wet bulk+gen cargo also operating in windy areas. There is less power available from the wind as a retrofit because the hull isn't as well optimised (being built for diesel) and the larger vessels need much more propulsive force. There are definitely ship types we won't ever expect to see using wind - containers who use the deck space; ships operating in, say, the Mediterranean where winds are not great - there would be insufficient payback. 15,000 is a very broad number - because technical suitability doesn't necessarily equate with commercial desire or political stimuli. It is designed to show that whilst the fleet is heterogenous and some ships will really struggle to be renewable powered, not all would and we may be able to bring the whole fleet's GHG impact down by focusing on the 'easier' ship types.

LK: Mr. Allwright, do you envision 100% wind powered or hybrid ships?

Gavin Allwright: All wind propulsion vessels are hybrid designs with either the wind acting as the primary source of power backed by auxiliary engines or as a wind-assist system. Vessels that are designed primarily for wind can of course use 100% wind power at times, however the need to meet schedules, at times of limited wind strength etc. means most voyages will be a combination of wind and motor. The motor power can be supplied by standard fuels, biofuels, batteries or in the future hydrogen.

LK: The IMO’s 2020 sulphur cap regulations, from what I have read, will prompt more widespread use of LNG fuel. How, do you think, you could convince an industry to go wind instead – as either switch will require changes in the ways ships are constructed, or retrofitting. Would you say the retrofitting would be equivalent in cost, or would one be higher cost than the other?

GA: IWSA’s approach is to increasingly deliver information on the toolbox of wind propulsion technologies – emphasizing that there are solutions already available that can get us a significant way down the road towards the zero-emissions vessels that we need. Ultimately, there are two main things that will convince the industry of the viability of the wind – first is 3rd party verification of the technologies available and the benefits of fitting these to fleet profiles already operating and to new designs. IWSA is collaborating with researchers to help create a robust version of that software.

Secondly, the need for demonstrator vessels, testing the wind power systems in real conditions and across all sectors of the shipping industry. Once we see these vessels more prevalent, then we will see commercial interest pick up. The recent EU commissioned report by CE Delft estimated the maximum market potential for bulk carriers, tankers and container vessels to add up to around 3,700-10,700 installed systems until 2030, including both retrofits and installations on newbuilds, depending on the bunker fuel price, the speed of the vessels, and the discount rate applied.

The use of these wind propulsion systems would then lead to CO2 savings of around 3.5-7.5 Mt CO2 in 2030 and the wind propulsion sector would then be good for around 6,500-8,000 direct and around 8,500-10,000 indirect jobs.

LK: You mentioned that wind would help with C02 emissions as well as create jobs. What about fuel cost savings?

GA: Retrofitting vessels with wind propulsion technology could potentially deliver 10-30% fuel savings, and for new builds that savings would be as high as 50%.

LK: Can you tell me a little more about your organization International Windship Association (IWSA)?

Gavin Allwright: IWSA was founded by a group of wind propulsion proponents, all identifying the need to tackle shared barriers, create a collective segment approach and to deliver a package of information to the industry and decision makers so they could see the basket of technologies are an increasing credible, viable and necessary low carbon/low emission solution for the industry

I was one of the founders, and the first elected secretary. The association has grown from the handful of founding members and supporters, to over 35 members and a growing group of registered supporters along with a large network of other supporters in the space of 2 years. These include 20+ technology providers, 10+ shipping projects, design and naval architect companies, research institutes and leading universities, wind propulsion and shipping experts and NGOs.

LK: What is the shipping industry’s reaction, in general, to IWSA’s ideas of using wind power?

GA: The body of information surrounding wind propulsion and the understanding of the benefits/costs involved has been growing, even at a time when oil prices have been at historic lows and ROI’s are challenging for all new technologies. However, the pipeline of regulation (Sox, Nox, PM) tied with the increased pressure and inevitability of CO2 MBMs and other measures being considered has continued to drive project development and interest.

The shipping industry in general has shifted from questioning why it should consider wind technologies, to one of accepting that wind will be part of the propulsion mix in the future, but the question now is ‘how do we get there?’ We are increasingly engaging with ship owners and operators, supplying them with updates etc., also we have been welcomed to numerous international fora to present progress in the sector.

LK: Ms. Gilpin, your website says that you see "digital tech as an enabler of disruptive maritime renewables tech” and your organization is developing a suite of smart analysis tools to create “shipping systems fit for the future”. Can you give me an example of how your proprietary data analysis tool "Tradewind" works to enable maritime renewables?

DG: Using 25 years of hindcast/historical weather data (ie statistically what wind speeds and directions/weather patterns typically prevail) we can predict the amount of 'usable' - aka 'free' - renewable energy available on a particular ship type/size, travelling on a particular route at a required operational speed. We compare this against a comparable fossil fuel powered ship on the same speed and route. Which allows us to quantify the amount of fuel saved by the renewable energy.

Using this fuel saved information we can create the fuel saving performance benchmark for the tech, eg: we'll save 15% fuel over a year compared to a conventional ship; this in turn allows us to agree contracts of afreightment which are lower cost and are predictable (ie not fluctuating with price of oil) and so give cargo owners less volatility in their business.

It's a mash-up of several digital systems created to support A. renewable energy onshore B. aviation fuel saving and C. offshore yacht racing weather routing combined with a database of all ships in the global fleet. Tradewind then supports crews as a decision-making tool when the renewable energy is deployed on ships. Only now we use forecast weather

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