Asia’s battery tech makes case for middle ground in hull efficiency

Hydrofoiling is impressive, but the cost and complexity alienate the consumer and limit market penetration.

If you follow news in the marine world recently, it would have been hard to miss the mega-deal signed in the Maldives by cutting-edge electric boat company, Navier. The roughly $100m contract signed with JIH Global, a hospitality and real estate development brand, will deliver 100 of Navier’s hydrofoil-technology vessels to the Maldives over the next three years.

This is good news for everyone involved in the marine industry in Asia as it pushes our region towards widespread adoption of electric vessels. When Navier’s vessels deliver on their promise, this deal will serve as a glaring example of how electric propulsion can reshape the marine environment in a positive way.

So far, the topic of conversation amongst nay-sayers focuses on the electrical grid question: Will the existing electrical grid of the Maldives be able to support the charging facilities needed to keep Navier’s vessels running at full capacity? Whilst this is an important question that is relevant to all marine electrification projects, the topic of hydrofoiling as a technology doesn’t seem to be in question at all.

Hydrofoiling technology involves the use of an underwater wing which, when underway, creates lift that pushes the entire hull of a vessel out of the water, reducing friction and significantly decreasing the amount of power needed to propel the vessel forward. Beyond the recent wave of hydrofoil-focused boating manufacturers such as Navier, Candela, and Vessev, competitive sailing has relied on hydrofoiling technology for many years.

On the surface, it may seem that all roads lead to the foil – and recent capital flows from venture capital firms seem to agree. However, whilst the technology is interesting and certainly provides the most efficient hulls that the world has yet to see, the technology itself remains complicated and expensive.

This begs to question: Are foils the only future?

Whilst the multiple benefits of electric propulsion, such as lower maintenance, less noise, and cleaner waters, may attract certain users, for electric vessels to achieve widespread adoption they need to compete with, or at least come close to, traditional combustion drivetrains in terms of speed and range.

To achieve this today, boats using electric propulsion must have convenient access to a network of high-power recharge facilities or be vastly more efficient in their power consumption than traditional options.

Hydrofoils solve the efficiency issue and that’s why this technology makes sense right now. 
But does this need for hyper-efficiency remain relevant once battery technology advances?

Asia’s battery giants such as CATL and Samsung are working at breakneck speed to improve battery technology and increase the power density of their products. Current commercially available battery packs typically have an energy density of 250 to 300 watts per kilogram.

Advancements in solid-state battery technology, such as the Samsung SDI (Silver-Carbon Anode) and the CATL sulfide-based solid-state battery, point to a future where battery packs may hold significantly more power than they do now, with stated targets of 350 to above-400 watts per kilogram.

This could mean that battery packs providing double the range of current solutions whilst maintaining the same size and weight are on the way.

Whilst hydrofoils may be the only obvious way to make the electric vessels of today compete with traditional combustion propulsion, when battery technology advances, the highly complex, software-heavy aspects of hydrofoiling may prove to be far riskier than they are advantageous.

These systems are reliant on optical recognition, incredibly accurate sensors and motors, and complex computer systems to control the boat whilst it “flies” above the water. In the tough marine environment, complexity is often the greatest cause of failures. Complex systems have more points of failure, more parts to be maintained, and require specialised technicians to troubleshoot.

In a world where battery technology has advanced to hold more power in the same package, the logical choice may be to strive for a middle ground – simple, easy-to-maintain boats that stay in the water, yet still achieve impressive speed and range due to improved energy storage.

Hydrofoiling technology is undoubtedly impressive and can have a wide impact on our industry, but the cost and complexity of these systems alienates the average consumer and limits potential market penetration. If advancements in battery technology reduce our need for the ultra-efficiency provided by foils, the winners will be the manufacturers who kept simplicity as a core principle and maintained prices at an attainable level.

In the future, traditional boat hulls designed for combustion propulsion will not cut it for electric propulsion systems, but we likely don’t need to go so far down the complex route of hydrofoiling. If you believe that battery technology improvements are rapidly approaching, the middle ground makes much more sense – efficient, simple hulls, on vessels designed specifically for electric propulsion.