The auto industry is ending its dependence on fossil fuels; General Motors said in October that “the future is all-electric”, and brands from Volvo to Jaguar Land Rover have set specific deadlines by which they will only make electric cars – as soon as 2019 in Volvo’s case.

However, in the US maritime industry, electric and hybrid propulsion systems are still little more than curiosities for many – despite the fact that international regulations, including the International Maritime Organization’s Ship Energy Efficiency Management Plan, are placing greater restrictions on greenhouse gas emissions.

Compared with fossil-fuel equivalents, electric propulsion systems cut emissions of carbon dioxide, nitrogen oxides and sulfur oxides; reduce fuel and maintenance costs and improve passenger journeys by eliminating engine noise, fumes and vibration. So why have they not yet become a mainstream choice for shipbuilders?

The current maritime-propulsion industry – from procurement to installation, replacement and repair – is mature, established and comfortable. The manufacturers of both diesel and gas turbine propulsion systems are reputable; they’ve been working within the industry for years and, as in other industrial sectors, their warranties, maintenance and long-term support services and practices are viable and well established.

For many shipyard owners, propulsion systems integrators and naval architects, why change? What’s the incentive? As the old saying goes: ‘If it ain’t broke, don’t fix it.’

In addition, US ship owners do not benefit from the kind of tax breaks or inducements offered to their counterparts in Europe, where financial incentives, in conjunction with environmental regulations, are driving the switch to electric and hybrid propulsion.

You may think that the upfront costs of installing an electric hybrid system are higher than those of conventional propulsion systems, but this is actually not the case. In fact, the hybrid configuration enables the reduction of the size of the motors and the number to be installed. At the end, the upfront cost of electric hybrid propulsion is equal to the cost of conventional propulsion. Operational benefits are also very attractive, these include:

• Cost savings beginning immediately, with smaller or no fuel bills, and lower maintenance costs throughout the life of the vessel. Taking a total cost of ownership or life-cycle cost view gives electric and hybrid propulsion the edge.
•  Electric or hybrid systems are scalable; once the shipbuilder has assessed what they need, systems can be scaled up or down to suit every size of vessel. And for military customers, energy storage is not limited to propulsion; batteries can be used to power radar and other defense applications.
• Lower emissions bring vessels into line with increasingly stringent environmental legislation around the world. Emissions from shipping currently represent 3 percent of the world’s total greenhouse gas emissions. Without significant improvements in energy efficiency, that proportion could rise to 15 percent by 2050[1].
• Battery-powered propulsion systems are quiet and clean; no more diesel fumes, vibrations and engine noise. For passengers, this is one of the most significant benefits. I had the chance to experience this myself on a recent trip to Canada during a river crossing on an all-electric ferry. It is fair to say that the quiet was… “deafening!”

To be sure, in certain sectors and parts of the country, US shipbuilders and owners are already doing their homework. Washington State Ferries, for example, is looking into converting part of its fleet to hybrid electric.

Speaking on this subject at the recent SmarterShips Conference, I was delighted by the level of interest shown by naval architects, shipyard owners and equipment suppliers. With electric-vehicle technology becoming an increasingly important part of the energy mix, the time is now for our industry to seriously examine the possibilities of electric propulsion.

The writer served as a Captain in the US Navy for 31 years and now manages Defense and Maritime Sales for Saft in the US. He is based in Cockeysville, MD. Saft makes specialized batteries and energy storage systems for industrial, defense, aviation, rail, maritime, telecoms and civil electronics customers around the world.