Solar panels make smart use of available space
Continuing our section bringing news of freight developments on the inland waterways. Jonathan Mosse reports.
AS IF setting out to sea without a crew wasn’t radical enough, using electricity as the sole motive power would certainly appear to be ‘putting the tin hat on it!’
While vital to the global economy, the shipping industry nevertheless creates around 3% of total greenhouse gas emissions so the Yara Birkeland, as the world’s first autonomous, electrically propelled cargo ship – if successful following her launch at the end of this year – has a significant role to play.
The Department for Transport (DfT) has recently consulted on future fuels for deep sea and Domestic Maritime shipping with a view to establishing a use pattern compatible with projected availability and perceived suitability for the different sectors involved. Ammonia and natural gas are on the cards for deep sea navigation while, closer to home, ‘diesel’ derived from waste plastic and algae, together with Hydrotreated Vegetable Oil (HVO) – using waste cooking oil and animal fats – appear better suited to inland craft.
Relying on battery power, therefore, represents a radical departure from current thinking, so I’m sure DfT will be watching the Yara Birkeland with great interest as she plies between the two Norwegian towns of Herøya and Brevik with cargoes that would usually be carried by road, replacing an anticipated 40,000 lorry journeys a year.
Globally, more than 90% of all trade is seaborne and shipping is not currently covered under the 2015 Paris climate agreement, so any initiative that reduces total greenhouse gas emissions is to be welcomed. Able to carry 120 x 20ft containers at an optimal speed of six knots, the Yara Birkeland (costing £18 million to build) derives her motive power from a massive 7MWh battery bank.
Topping up a ship-sized battery bank is all very well if time, tide and your wallet allow but harvesting power directly from the sun, while under way, looks like a somewhat more attractive proposition. The Rotterdam start-up company, Wattlab, has spotted the potential of adorning the hatch covers protecting the holds of domestic shipping with a solar panel array and is now well into the prototype stage.
Bo Salet, co-founder of Wattlab says: “With the energy transition, we have to make smart use of the space that is available. We are developing new applications for solar energy and generating energy where it is needed.”
He goes on to observe: “Here, we develop and design. This workplace has been set up for rapid prototyping. We compose the various layers of the panel ourselves and thus create solar panels with specific properties and shapes. In this way, we can make a wide variety of solar panels which meet unique requirements. From wafer-thin lightweight solar foils and bendable robust solar panels to flexible panels in any random shape.”
The sheer size of vessels that now regularly ply the inland waterways of Europe means that they can accommodate a realistically sized array of photovoltaic (PV) panels in terms of both the power required to propel the vessel and, of equal significance to the owner/captain, one that has an economically viable payback period, in this instance somewhere in the region of five to eight years.
Each hatch has a 2900KWh array and on a 110m barge there are, in total, 22 hatches. When Wattlab first ‘set sail’ its greatest challenge lay in understanding the constraints imposed by the lightweight design of typical hatch covers and, of perhaps far greater significance, grappling with ways of overcoming the essentially fragile nature of PV panels in what is an extremely hostile environment.
Today, they have achieved a robust design that gets the array itself, along with all its connectors, within the 30mm thickness of a cover. Initially, Wattlab devised a system of lightweight panels on roller shutters before turning its attention to the more common ‘friesche kap’ stackable panels.
Whether we are talking about smartphones, or propelling a 3200 tonne ship like Yara Birkeland with electric motors, energy storage has always been the Achilles heel: an area of development that lags behind the ‘product’ itself. The energy density of hydrocarbon fuels, such as gas oil, is somewhere in the region of four times greater – on a volumetric basis – than can be stored in a lithium battery and 15 times greater than the same amount of energy stored in a lead acid battery.
However, it starts to become interesting when a smidgen of lateral thinking is applied to this fundamental problem. Equivalent to the energy capacity of about 36 electric cars, the Wärtsilä swappable battery container – designed to be fitted to a 104 x 20ft inland container vessel – is fully equipped with safety systems, including an onboard fire protection skid and comes pre-wired for remote monitoring.
When depleted it is simply exchanged for a fully charged replacement at a recognised charging station and the vessel’s owners billed for the actual energy consumed.