climate change transport

Sustainable shipping – the return of the sail

In the past, all shipping was by renewable energy. Global trade got established with nothing but the wind, from the great trade routes out east, to the infamous triangular trade between Africa, the Americas and Europe. It was all under sail.

Coal power replaced wind power in the 19th century, and then heavy oil dominated in the 20th century. Today most ships run on diesel and heavy oil, and it takes a lot of it to move an ocean liner or a tanker. Shipping is a major source of carbon emissions, an estimated 1.2 billion tonnes a year, twice the footprint of aviation. There’s an embedded CO2 cost to every imported item we ever buy, but since the emissions occur in international waters, they are often discounted from national carbon accounts and effectively ignored.

It is often assumed that as we deal with climate change, many industries will ‘come home’ or relocalise. Food production is likely to be more local, and manufacturing jobs will relocate as the cost of shipping escalates. But that doesn’t mean that there will be no international trade in future. Some things are best made centrally and are too specialist for local production. Other things can only be produced in certain areas. Future warming notwithstanding, I very much hope that I won’t be limited to British wine and coffee in twenty years time.

One area of research is hybrid power, with ships using solar power to run onboard functions such as lights, steering and navigation. The deck of an oil tanker or container ship has a large surface area that can be fitted with panels, saving fuel for the grunt work of propulsion. Others are experimenting with complementary wind power, such as fitting a computer controlled kite to the front of the ship. Depending on wind conditions, Skysails can cut fuel consumption by 10%-35% and most large ships could be retrofitted to fly them. The experimental Viking Lady is a Norwegian ship that runs on LPG fuel cells. At half the emissions of standard diesel combustion, the owners like to claim that it is most environmentally friendly cargo ship in the world.

I don’t agree. None of these sorts of developments will make truly sustainable shipping. For that, you need to avoid fossil fuels altogether and run on renewable energy. That means revisiting wind power. Despite the romantic notions that may come to mind, we’re not talking about fleets of old wooden boats. Modern sailing ships come with computer-controlled sails and guidance systems. The more cutting edge vessels don’t have the ropes and rigging that we normally associate with sail, but large blades that turn to the wind. Commercial scale container ships like this are still on the drawing board, but the technology is proven in prototypes like the Maltese Falcon.

The ship pictured here has been designed for a company called Fair Transport. They already offer wind-powered shipping services, so you don’t have to wait for their container ship of the future should you wish to ship your goods by Brigantine.

Another group working on zero-emissions shipping is the Greenheart project, a crowd-funded initiative to develop a shallow-hulled, single-container boat that can operate with no fossil fuels and with no port infrastructure. The plans are being drawn up on a non-profit basis and the designs will be open source, aiming to create a multi-purpose transport ship for the developing world.

We’re a long way from truly sustainable shipping. Even if project like the FairWinds Ecoliner here get funded and built and prove competitive on speed and price, it will take decades to phase out and replace our existing fleets. That means there’s plenty of work to do on improving efficiency in the meantime – and one of the simplest is to just to impose a speed limit on ships.


  1. Thanks for helping spread the word on the Greenheart project,
    Our project is part of the new wave of windship projects and we are developing a pilot project in the South Pacific. For least developed coutries, the use of wind and solar is a low cost, reliable and sustainable option – we are seeking additional funding from institutional and commercial funders and the crowd funding element is also bringing supporters and the general public on board too
    The next year will be an exciting one for the windship projects out there – we will be moving this sector forward together and we look forward to a lot of news and debate around the use of wind in transport.

    Greenheart team

  2. Commercial shipping is a crucial part of the world’s infrastructure – ships carry everything from high-tech electronics to basic foodstuffs. The industry accounts for 3 percent of all annual global emissions , so it makes sense to make shipping as efficient as possible. With that in mind, Japanese company Eco Marine Power has devised the Aquarius Eco Ship , which harnesses the power of the wind and sun to lighten its environmental impact.

    1. Yes, kites have apparently been quite successful in trials. I hear Cargill are hoping to retrofit them on many of their ships.

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