Wind-powered shipping

Commercial and regulatory challenges are driving the development of new technologies and strategies for the design and operation of ships.

To date, most improvements in ship fuel efficiency have been realised through changes in behaviour, such as slow steaming, and reductions in installed power, to meet the Energy Efficiency Design Index (EEDI) requirements. New fuels – mainly LNG – and hybrid technologies have been adopted by North European and North American operators of niche, small or specialised tonnage – such as ferries. Meanwhile, mainstream cargo shipping has yet to make significant technology or operational step changes. And the dramatic decline in the price of oil and ships’ bunkers during 2014 has reduced the operators’ incentive to reduce energy consumption – for now.

To meet potential demand for lower energy consumption and to reduce carbon emissions, an increased number of energy saving and new technology concepts have been emerging. Many of these concepts are not fundamentally new but benefit significantly from new understanding, materials and methods. One of these old concepts with a new lease of life is wind-assisted propulsion.

Sailing merchant ships reached their technical peak during the 1840s. Clipper ships were superior to early steamships, which were considered inefficient and slow, and sacrificed cargo space for machinery and bunkers. The introduction of the triple expansion engine and, later, the diesel engine, combined with the exponential growth of the merchant fleet (and the need for larger ships), made sailing merchant ships obsolete.

Renewed interest in wind-assisted propulsion in the 1980s was driven, similarly to today, by the oil crisis of the 1970s. But by the time the technology was showing promise, fuel prices had stabilised and put a brake on further development and adoption. It can be argued that, in 2015, wind-assisted propulsion technology faces the same threat – reduced incentive from falling bunker prices – despite its potential double-digit fuel savings. But today, we live in a different world, one where many organisations see additional benefits in reducing their carbon footprint and dependence on fossil fuels – benefits beyond reducing operational costs. In this respect, wind-assisted propulsion offers one of the few realistic options for introducing renewable power into shipping.

While merchant shipping abandoned wind more than a century ago, the technology never stopped developing in the racing yacht sector, to the extent that Americas Cup yachts (the equivalent of Formula One cars) can sail faster than the wind.

For wind-assisted propulsion, the challenge, perhaps, is not developing new technology but taking existing technology in an advanced form and adapting it to merchant shipping. In order to do that, there are commercial, technical and regulatory challenges that need to be addressed, and barriers that need to be overcome.

This report describes and considers these challenges and barriers, and hopefully generates a debate about how wind-assisted propulsion might reach its unfulfilled potential.