TechAltar

Electric ships are slowly starting to make sense

The Touanor, the first solar-electric ship to circumnavigate the globe in 2012, still appears futuristic, with mass-market adoption of electric ships lagging behind electric vehicles. However, momentum is building. Recent announcements include China's first 10,000-ton fully electric container ship, Norway's order of 20 electric Candela P12 ferries, and BYD, the world's largest battery maker, launching a new business unit for marine batteries and electrical systems. Earlier, Incat Hull 96 became the largest electric ferry, and the Silent Yacht 62 was the first production yacht to cross the Atlantic primarily on solar power. Electrifying ships faces two primary challenges: charging and energy consumption. Charging is straightforward for small boats at marinas but difficult for large ships needing specialized ports and unable to refuel at sea, limiting range. The second challenge is the immense energy required to move ships through dense water, especially at higher speeds. Water's density necessitates significant power, and as ships accelerate, they create increasingly larger waves. Reaching "hull speed" drastically increases energy consumption, and exceeding it requires hulls designed to lift out of the water (planing), which is also energy-intensive. Hydrofoils offer a solution by lifting the hull out of the water, reducing energy consumption by up to 80% at high speeds, but they add significant cost and complexity. Consequently, electric ocean liners or very fast ships are not feasible in the near future.