Hybrid technology for fishing and aquaculture
The Maritime Aquarium at Norwalk research vessel 'Spirit of the Sound' is equipped with BAE Systems HybriGen technology
In 2016 two significant developments are going to make many owners, operators and builders of fishing vessels consider hybrid marine power.
Firstly the new emissions laws in ports and secondly there is now an incentive for high technology manufacturers to invest in developing highly efficient batteries.
Hybrid is ‘here and now’ technology that is being utilised by many industries around the world. We are now entering a period of rapid change and commercial opportunity in the marine industry as it recognises the potential of utilising hybrid power and innovative propulsion systems for all types of vessels.
Aquaculture and the
sounds of silence
Most professional maritime sectors cannot afford the luxury of going green for the sake of it, they will simply consider whether hybrid solutions can reduce their fuel costs or maintenance costs. This will be relevant to many aquaculture operators, however, there are other drivers in this sector and a major one may be the sounds of silence. A hybrid diesel-electric system, using stored energy in batteries, could enable a vessel to leave the dock in silence before first light. Work parties could arrive at the fish farm having switched to electric a few hundred metres from the facility. The vessel could then travel between fish stock sites on main diesels. For night fishing, operators could enter pristine anchorages after dark in silence on battery power.
In ponds, lakes and enclosed fjords the toxins from diesel emissions can build up over time. Aquaculture is sometimes part of an environmental rehabilitation program or as an aid to conserving endangered species.
An important aspect for improving welfare of marine organisms is to reduce stress to a minimum, as prolonged or repeated stress can cause adverse effects. The commercial aim is to enhance production when farming aquatic organisms including fish, molluscs, crustaceans and aquatic plants. Running zero or low emission emissions vessels is a logical objective for operations working with filter-feeding molluscs and shellfish including oysters, clams, mussels and scallops.
Hybrid and electric aquaculture
There are many small and medium size hybrid vessels now being built around the world. With the engineering proven, particularly in 6-12m (20-40ft) craft, designers can now integrate this with the requirements of aquaculture operators. A vessel that is only used for short runs to and from the shore could be electric only. A hybrid vessel, for example using diesel main engine with the option to switch to battery electric power, will give greater range when running at speed plus the capability of running silently and with zero emissions around a fish farm. The hybrid aquaculture support vessel can re-charge its batteries from its own diesel engine during the day or simply plug in and charge from the dock overnight.
Hybrid Power Systems
There are currently two main types of hybrid system. Firstly a serial hybrid, where the engine in the system only powers a generator and is not mechanically connected to the propeller shaft. Secondly a parallel hybrid, where the engine is mechanically connected along with an electric 'machine' that can operate as both a propulsion motor and a generator. The reduced electric propulsion, generator and battery demands of a parallel system substantially reduce the cost compared to a serial system. Parallel systems are more likely to win initial market acceptance because of a perceived greater reliability, as the ‘trusted’ diesel engine is still connected to the propeller shaft with the electric propulsion adding a redundant system.
The benefits of hybrid systems include improvements in energy reliability, increased fuel efficiency, lifecycle cost reductions and reduced emissions. BAE Systems is a provider of hybrid power systems with technical experience in hybrid technology for land based applications. David Adamiak, Senior Manager of Business Development at BAE Systems HybriDrive said, “From over 10 years’ experience supplying hybrid technology to land transport sectors we know that cost-benefit calculations start with the initial purchase of the system. Payback periods can be based on the life cycle of the vessel and life cycle of the hybrid power system. Once a system is defined projections of savings can be based on engine management data linked to work cycles.”
Hybrid systems are infinitely scalable which enables owners to specify what they are trying to achieve over a period of time or an entire fleet. David Adamiak added, “We supplied a HybriDrive system to the 19m (62ft) research vessel Spirit Of The Sound. She runs virtually silently on battery electric power for two hour study cruises on Long Island Sound.”
Hybrid systems and ‘The Hour
‘The Hour Of Power’ has been well received by the marine industry worldwide. This simple concept enables vessels to run in and out of port for an hour on electric with battery power - then carry out their open sea work on diesel power. The aim of this innovative hybrid solution is to enhance conventional power and propulsion systems. Vessels can reduce emissions and improve fuel consumption whilst extending engine maintenance periods and engine life.
This is not just green energy for the sake of it. ‘The Hour Of Power’ focuses on hybrid solutions linked to viable business cases. Speed limits in harbours and channel approaches at the beginning and end of daily transits may mean that ‘The Hour Of Power’ is all that is required for the electric part of the cycle. For commercial and professional organisations the concept of running vessels with zero emissions at up to 10 knots for one hour will shape decisions that lead to improvements of in-service systems and procurement of next generation vessels. The overall objective is fuel saving and improved efficiency by all means.
Next generation cells
The next generation of cells and batteries are key technology developments that are making marine hybrid systems potentially viable. Battery chemistry such as Lithium-ion offer impressive power solutions and the business case is starting to fit for commercial operators. Since there is no single system that fits every application it is important to work with manufacturers that have flexibility in cell manufacturing and offer scalable solutions. New factories with fully automated processes are designed to ensure consistently high quality cells and quality control of the entire battery management system.
The marine sector can learn from battery advances in aviation and land transport sectors. Michigan based XALT Energy offer several variants of High Energy, High Power, and Ultra Hi-Power cells. Robert Young, Technical Lead for Marine Applications at XALT Energy, said, “Our team of engineers have worked to the highest standards developing electric and hybrid energy solutions for the automotive sector. XALT Energy not only has the necessary knowledge, but also the experience of taking high voltage battery projects from concept through production into the finished system.”
He added, “Running on low load or tickover is particularly bad for diesel engines of all sizes. We can now calculate the kilowatts required to achieve a target, such as running the vessel at 10 knots for one hour at different stages in the day. From this we can specify to an end-user or naval architect how much space the battery installation will take up onboard, how much the system will weigh and most importantly what will be the cost-benefit and pay back period. XALT Energy is also working with the main classification societies to develop the highest levels of safety standards from individual cells to complete battery management systems.”
Many fishing and aquaculture companies have already worked to build up green credentials. For the next generation it will be hard to justify millions of dollars spent on green marketing campaigns if the workplace vessels have not considered the environment.
For naval architects working in the fishing sector class rules, safety, performance and cost are relevant when considering innovative battery power and diesel electric propulsion systems. With vessel life cycles of over 20 years, naval architects and builders of new craft will offer next generation engine room designs that have space and access routes to enable retrofit of hybrid installations. Designers will need to create hybrid solutions which demonstrate genuine benefits plus are manageable in terms of physical size, weight and maintenance.
As new sources of energy become available it is important to identify which energy source best fits the vessel, duty cycle and environment to give efficient power when it is needed. Since no two vessels, routes or captains are alike, decisions can be improved with data logging and analysis. As shipping, land transport and aviation move rapidly towards hybrid solutions it will be interesting to see how the fishing and aquaculture industry decides to utilise the numerous opportunities.
John Haynes is an Associate Fellow of the Nautical Institute, a Yachtmaster Ocean and Advanced Powerboat Instructor. Subject matter expertise includes high speed craft consultancy, product development and specialist training. He is Operations Director of Shock Mitigation www.shockmitigation.com and founder of the RIB & High Speed Craft Directory that brings together specialist boats and equipment for the sub IMO sub 24 metre professional sector worldwide www.ribandhsc.com.
Next Generation Marine Power & Propulsion Conference – Southampton UK – 26 to 28 April 2016
This unique event brings together an international group of experts, to identify the potential of utilising new sources of energy, including hybrid power and propulsion systems. Attendees will include professional, commercial and military end-users, boat operators, boat builders, engine manufacturers, mechanical & electrical engineers and naval architects. Conference website: www.hybridmarine-power.com