Frederick M. Lowther
Much has been made of the future of electronic vehicles (“EVs”). Governments around the world are setting ambitious goals for EVs based on the notion that the vehicles themselves are carbon-free and thus a climate-friendly alternative to internal combustion vehicles. Among other things, the prospect of millions of EVs has supercharged the battery industry and spurred efforts to develop new energy storage technologies. So why not electric vessels, or vessels which are in other respects carbon-free?
There are many obvious differences between EVs and oceangoing vessels: size, weight, distance traveled, water-resistance, etc. Nonetheless, there is no inherent limitation on using an electric propulsion system for a vessel; it’s more a matter of scale rather than feasibility. The real issues are cost (capital and operating) and, just as important, the net environmental impacts.
Cost and Operational Considerations
On the cost and operational side, there are a number of key considerations. In listing the issues, I am focused on newly constructed vessels versus retrofits (but some of the same considerations would apply to retrofits). What is the weight of a battery/electric propulsion system versus diesel or turbine engines and a load of fossil fuel? Batteries are very heavy, and weight is a significant factor for vessel operations. What is the cost of the system(s) to keep the batteries charged, both at sea and in port? The single biggest issue with EVs is the operating distance between charges, and that would be a significantly greater issue with oceangoing vessels, especially those traveling over vast stretches of water. It’s the difference between hundreds of miles and increasingly frequent options for recharging EVs versus thousands of miles with no “in transit” recharging stations for oceangoing vessels.
To the extent that batteries are recharged in port, the time required for recharging becomes crucial since the in-port turnaround time for many vessels is very short, often measured in hours. If (as is highly likely) the vessels are hybrids (i.e., include engines or other devices that can charge batteries while the vessel is in motion), that adds to the cost/weight equation (as well as the environmental equation). What is the operating life of the batteries and what is the cost of replacing them and disposing of the spent batteries (another environmental issue)? Battery life/disposal has not (yet) been a major problem with EVs, but that platform is far different from an oceangoing vessel platform where the constant demand for power over long periods of time and against the resistance of water impacts battery functionality and life. Finally, batteries stacked in large bundles (as is the case for wind and solar generator storage installations) are known to have elevated fire risks. What is the cost of appropriate onboard vessel fire suppression systems? Continue reading “Carbon-Free Ships: The EVs of the Seas?”
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