Greenheart Project

Is it possible to achieve not just incremental efficiency gains of 5, 10, or 20%, but true, 100% green shipping using present technology?

The Greenheart Project was born around this question. Starting with a requirement that solutions must be 100% emissions-free, we looked at what technologies existed to propel a ship carrying cargo across the open ocean with reasonable speed and reliability. What we found was that, yes, at least one viable fuel-free solution exists: sail/PV (photovoltaic) hybrid systems.

The sail part of sail/PV is easy to imagine. Mankind has navigated the oceans using the wind and currents for thousands of years. There is no reason in principle that commercial sail propulsion could not still work today. In fact, it does work today - there are a few small commercial sailships making a profit moving low volumes of niche-market freight back and forth across the Atlantic as you read this.

The PV part of the hybrid propulsion is short for PV-charged, lead/acid battery banks driving DC electric motors which turn the propellors. Electric drive systems have proven themselves a reliable replacement for internal combustion engines in various smaller applications. Submarines, fleets of urban delivery vehicles, and now, the fastest dragsters are powered by electric motors and batteries. Charging battery banks with PV provides a solid state, and thoroughly dependable source of power in lower latitudes. The Planet Solaire, a 95-ton, PV-only demonstration craft, is motoring around the oceans right now, and should soon become the first PV-only vessel to circumnavigate. Now a 50-year old technology, PV is so reliable, that it is the usual choice of power for spacecraft and satellites where maintenance and refueling are impossible.

Using both sail and PV

A combination of these two, sail and PV, could provide robust 100% emissions-free power, using immediately available, well-tested technologies for small vessels.

A practical limit to the size of sail-only vessels was being pursued in the windjammer era at the turn of the last century, when coal began edging out wind in business efficiencies. Sailing masts gave way to derricks. A hundred years and a considerable rise in fuel prices later, the attraction to the idea of “steaming on air” led to a renewed interest and exhaustive inquiry into one aspect of sail by the Danish government and the venerable Knud Hansen. That 1990 study, of a 50,000 dwt theoretical windship, showed only a 10% cost difference between their sail/internal combustion engine hybrid and a conventionally-powered vessel of the day, when plying a standard freight trade with favourable wind probabilities - some fuel savings, a slight cost increase, and possibly some compensation for externalities.

However, what about smaller vessels and different applications? Shallow vessels have access to an enormous number of local ports and offer a far wider range of possible business applications. Freed of the cost calculation of 'fuel per mile', are direct long routes that bypass deep water hubs and transfers waiting to be exploited? What size of ship could be both 100% clean and broadly profitable? How would such 'distributed' shipping affect flow, volume and routing of freight in developing, and established trades?

We believe that as solar-electric technologies improve, such sail/PV hybrid systems could expand to the size of the larger windjammer class vessels - about 200 containers worth of freight capacity. For the present moment however, using relatively cheap, proven, and available technologies, Greenheart has designed a multi-purpose, sail-solar industrial vessel with a 3 x 20-foot container (3 teu) hold size, and about 60 tonnes of cargo capacity.

Greenheart’s prototype design is a 32m, 220 tonne multipurpose ship, with a single A-frame mast/crane.

Primary propulsion comes from 300 m2 of sail, fore and aft rigged - like modern sailboats. For auxiliary propulsion and onboard power, a 125 m2 photovoltaic array will gather energy for enough lead/acid battery capacity to allow the ship a 55 mile range under power alone. The ship’s two 200kW DC drive motors + bow thruster can be used for approaches and departures, motorsailing, and when the wind is more than adequate for propulsion, as another way to charge the ship's battery banks. A hull speed of 10-11 knots is anticipated, with unlimited range.

Much thought has been put into flexibility and port independence to minimise environmental impact and maximise usefulness in the developing world, and in applications such as fishing and ecotourism. A shallow draft design for beach landing is accompanied by a roll-on/roll-off port ramp, hinged just above the waterline in the stern. It can be lowered into the water for launching and shipping boats, or for handling fishing gear. The mast/crane reaches over bow and stern for cargo handling, or can be lowered to the deck in cases where low clearance or low wind resistance is necessary (e.g. going upwind and under bridges), or to allow dockside cranes to operate freely.

Concerns for overall sustainability means we also are paying strict attention to cradle to cradle design criteria, and are as much as possible limiting toxic materials in construction.

Cost for the first vessel is projected to be about US$500,000 with prices going down to half that as more vessels are produced. We hope to have the first prototype in the water as soon as late 2012/early 2013, with more vessels of different scales and specialisations following.

The question is, could ships of this type have a place in a 21st century economy where multi-thousand-container cargo vessels and huge economies of scale are the norm in high seas trade, and where fast, reliable diesels already power small ships in short sea and inland trades ? Where will these supposed profitable commercial applications for a 220 tonne sail/PV vessel be?

A Good Place to Start

Although Greenheart has received a lot of attention from established shipping interests in the developed world, we considered the zero-fuel, shallow access, long range,and undeveloped port capacities of the design to be especially well-suited to coastal regions where access to money and markets is a problem, but access to wind, sun, and water-wise labour is not. This is also the part of the world that will see the greatest population and market growth in the coming century, where the human needs are greatest, and where fragile marine environments are most threatened and least protected.

The many social and cultural benefits arising from succeeding with appropriate technologies in the least developed coastal regions, as well as their potential for competitive advantage while their wages remain comparatively low, and a good disposition for leapfrog technologies, all indicate promising opportunities for no-fuel hybrids servicing the poorest seaside and riverine communities.

A two or three container fuel-free vessel, especially one optimised for affordability and simplicity, at a cost that will lower barriers to full ownership and operation by developing world stakeholders will bring empowerment and natural optimisation, efficiency, and innovation towards the tasks that are most needed in those areas.

In addition, the smaller scale and relative port independence can be especially attractive to nations and regions that lack fully developed large port infrastructure and are as yet weighing the costs of building such infrastructure. Once building, dredging, road construction, etc. are all accounted for, new deepwater ports often have price tags in billions of US$. For least developed countries, this can be no small expenditure, and the infrastructure required to link various communities and other resources to the deepwater ports by land sprawls across regions. It often leads to budget overruns and upkeep costs, destroys vast swaths of previously untouched environment, and can drastically change the historic cultural geography of the region and draws its economic focus away from traditional maritime communities towards the now land-bound economic spine.

Instead of investing billions in a single deepwater port and associated infrastructure, a developing region or nation could choose to invest half, a quarter, or much less of the capital a deepwater port would cost, in building or maintaining networks of smaller local ports and subsidising the construction of hundreds, or even thousands, of smaller Greenheart-like vessels.

What will the shipping norms of the mid-21st century look like?

It’s not just a matter of environmental sustainability, but socio-economic sustainability - and resiliency - in the rapidly changing developing world as well. Does our present accepted model actually serve developing nations best? Or could another model (that also happens to be environmentally sustainable) propel them on a path of innovation towards a better long-term future?

Would a developing maritime nation with limited infrastructure be better served by a handful of 5000-container vessels or by hundreds (or thousands) of 5-container vessels? Should its government spend its resources building a new deepwater port, or perhaps instead consider subsidising a fleet that doesn’t need one? How might feeder systems and local trade be affected by different fuel/labour paradigms? These are questions we might ask ourselves in the coming years. In an industry like shipping, where assets can be enormously expensive and long-lasting, it will be important to anticipate the answers well.