Water-borne electric vehicles are much more than 100 year old river boats, toy boats on ponds and tiny trolling outboards for leisure fishing. The rapidly increasing military, commercial and industrial applications now dwarf leisure applications in value and sophistication. Autonomous Underwater Vehicles (AUVs) become larger and cleverer. Surface boats have a great deal of electric retrofit. Reasons include versatility, performance, laws and policies.
The Sulfur Emission Control Area will affect all shipping within, into and out of the Baltic, North Sea and English Channel from January 2015. SECA will limit fuel emissions from ships to 0.1% sulfur compared to the current limit of 1.5%. The Californian coast has similarly tough new legislation. International Maritime Organization rules now strictly limit sulfur oxide emissions by ships. Ordinary diesel and heavy fuel oil emit a lot of sulfur oxide when burned. LNG has virtually zero SOx emissions. All become more efficient and less polluting if hybrid electric power trains are used and these have many secondary benefits as well, not least performance. The Norwegian Government has a strongly green agenda extending to the electrification of tugs, offshore supply vessels and river and sea ferries.
Italy is a leader in electrification of boats and small ships. IFEVS has announced a double motor powertrain designed at the outset for boats, aircraft and cars, its first success being in small cars, where it gives four wheel drive. In marine equivalents, it gives space saving, redundancy, reliability and manoeuvrability. EEI Italy has developed Silent Propulsion System (SPS) which reduces fuel usage, increases available torque to the drive shaft and operates the reduced-size diesel engine at its maximum efficiency. Batteries become the primary source of supply to an inverter fed electric motor. This new marine system configuration reduces operating noise and vibration, exhaust emissions, thus resulting in a more pleasurable environment. The concept can be expanded to include other boat or ship loads.
The frequently updated IDTechEx report, Electric Boats, Small Submarines and Autonomous Underwater Vehicles (AUV) 2014-2024 gives full analysis and forecasts.