By Dr Peter Harrop, chairman, IDTechEx

30 May 2013 – Virtually all autonomous underwater vehicles are electric for practical reasons – the internal combustion engine (ICE) is not a realistic option. Not so on the surface, where the ICE is the favoured means of propulsion. However, even here, there is now a strong move to hybrid and pure-electric drivetrains for many powerful reasons.

The rapidly growing US$2.6 billion market for marine electric vehicles (EVs) will reach US$6.3 billion in 2023. It is unusually varied with average unit prices increasing as larger craft are electrified to improve cost over life, performance, green credentials and for other reasons. The market includes on-water and underwater electric vehicles for inland waterways and the sea. Military electric craft are the largest market sector by value today but e-workboats and other, smaller market subsectors will increase their share of market by value through the coming decade.

Not included in the above figures are pure-electric outboard motors or, for that matter, the hybrid electric outboard motors that will appear at some stage for the highest power and longest range. All these convert small dinghies and larger sailboats and workboats into electric versions. For now, very low power, low cost trolling motors for inland waterways are the main part of this market but several companies are starting to sell high power pure electric outboard motors up to 150 kW/ 180 hp and these permit water skiing on the increasing number of lakes where ICE is banned because of noise and pollution, from Taiwan and India to Germany and the USA. The market for electric outboard motors will rocket from about 60,000 to about 150,000 in 2023. The value market may quadruple or more because of the move to high power versions.

Looking at it another way, on-water craft dominate market value throughout the coming decade but underwater EVs can be exceptionally profitable and they are more likely to employ leading edge technologies, a bellwether of what will happen later on the surface. Hybrids will become more important due to their rapid deployment on the surface in applications where duty cycles or ranges are too onerous for current pure electric technology.

Some of the presumed driving forces behind our forecasts are as follows. Further green laws will be introduced, help leisure and commercial/industrial marine EV sectors to grow. For example, pure-electric craft benefit from laws that increasingly ban polluting alternatives on inland waterways. Plug-in hybrid powertrains will be favoured for the larger seagoing boats to save cost and improve reliability and performance over ones with conventional engines. By contrast, a substantial new market is being created by the advent of powerful, pure-electric outboard motors. Many new forms of expensive underwater craft will also appear. The seagoing vehicle market will be increased particularly by military build-up and a trend to understand the influence of the oceans on weather and to harvest the oceans, including minerals and livestock.

There is enlivened interest in on- and underwater electric craft for many reasons. Hybrid and pure-electric powertrains meet new emission regulations and make new missions possible. Of course, virtually all underwater vehicles are already electric but boatyards need to modernise. Those making other EVs or their components are also getting involved. They seek to expand their business and they find that marine EVs, particularly seagoing versions, are interesting as a market that is often more profitable and more open to innovation than on-road EVs, for example.

In understanding EV markets and trends it is absolutely vital to realise that their adoption is not usually for the popularly understood reasons. In fact, so far, marine EVs are usually financially successful where are bought because they:

  • Can be used under water.
  • Replace human effort including much maintenance.
  • Create little or no noise, air or water pollution.
  • Make new things possible.
  • Save cost over life.
  • Last longer.

Frequently, the successes combine many of these attributes. For example, tug boat companies will switch from diesel alone to hybrid electric because they will save 70% on fuel costs, which is expected to translate to a two year return on investment. Another reason is a 60% reduction on emissions over diesel, which is something that tugboats will need to meet future emission regulations.

Voluntarily saving the planet is rarely the primary reason why someone buys an EV, whether land, water or airborne. The moral of the story is that those dedicated to reduction of pollution should design exciting, convenient, stylish and novel craft that replace human effort, make new things possible and save cost over alternative procedures.

Examples of making new things possible are:

  • Tugboats with maximum power from stationary.
  • Record breaking acceleration (e.g. ski boats) and time to full power (e.g. tugboats) record breaking craft.
  • Leisure submarines provide fun and independence − people who do not scuba dive can explore under water.
  • Silent river boats permit undisturbed study of wildlife.
  • Military seagoing craft have little or no heat or sound signature for missiles to home in on.

Impediments to market growth include extreme fragmentation of the industry. This can make it uneconomical for many manufacturers to fit the new lithium-ion batteries, to take one example, because buying less than ten or so is disproportionately expensive. There are other, more specific barriers to rollout. For example, someone buying an electric aircraft or car can get finance but usually someone buying a small leisure submarine has difficulty.