Saft Unveiling Li-ion battery Technology for Marine Propulsion & Auxiliary Systems

August 26, 2010 by Jeff Shepard

Saft is unveiling its advanced lithium-ion (Li-ion) battery technology which it says offers interesting new possibilities for the creation of highly efficient and cost-effective marine propulsion and auxiliary systems. Saft states that it has a wealth of experience in the marine industry as a supplier of battery systems for emergency back-up, lighting, engine starting and other auxiliary systems. The use of Li-ion batteries for ship and boat propulsion applications is therefore a natural progression for Saft, based particularly on its broad expertise in delivering advanced battery systems for the railway and automotive industries, as well as underwater applications.

The company says that Li-ion battery technology can offer a number of key advantages for designers in the marine industry, including high-power and/or energy storage in a compact space and weight-saving package, high-efficiency, long calendar and cycle life (even when operating in extreme temperatures), and zero-maintenance requirements.

Saft anticipates that Li-ion technology will be of particular interest for hybrid propulsion systems in which the batteries work in conjunction with diesel (or possibly gas turbine) generators and electric motors. The specific advantages of this hybrid power approach will vary according to the type of application.

Hybrid power could offer significant improvements in fuel efficiency and CO2 savings for work boats that spend most of their time at sea moving into position and only operate at full power for very short periods. So rather than sizing a diesel engine for peak power, it can be specified at a more economical size for average power, with extra power drawn from the batteries, when required.

One particular target is tug boats, where in a hybrid configuration, a battery system operates in parallel for low power operation, and is then combined with a significant boost from a single diesel generator for infrequent high power operations.

There is also scope for load-leveling type applications (similar to diesel-electric trains) in which the diesel generator is maintained at a constant load – typically 80% of capacity – saving fuel, cutting CO&sub2; emissions and reducing maintenance.

Hybrid or full electric mode could be an attractive option for passenger ferries and shuttles that spend much of their operational life in harbor for docking and undocking. Switching to clean electric power when in harbor could save considerable CO&sub2; emissions, helping port authorities meet their environmental targets; it also offers much quieter operation to reduce the impact on the local community.

In leisure boats, such as yachts, a hybrid system will enable the vessel to switch to battery power for silent, low-speed running when entering harbour, helping to meet the growing demand from port authorities to reduce CO&sub2; emissions. The battery could also support hotel loads when the yacht is moored, providing a green, quiet and vibration-free alternative to running diesel-generators, especially when waiting for access to harbour power points.