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Hybrid propulsion system

In recent years and decades, yachting technology has advanced at an incredible rate and there is no doubt that some of the most exciting developments have been around hybrid propulsion. With a growing desire to protect our world and oceans, the use of hybrid technology is an exciting solution to developing luxury yachts that have the lowest environmental footprint, along with many other appealing benefits.

As more and more hybrid yachts and concepts are coming to market – including the options available from Bering Yachts – hybrid-powered yachts are increasingly proving to be a popular choice for forward-thinking yacht owners. The subject of hybrid propulsion is a fascinating one, that could cover many pages, but here we summarize key points of note. For those interested in learning even more than we have addressed in the following article the expert Bering Yachts team is on hand to discuss in detail the possibilities that hybrid can offer, together with the pros and cons. Want to learn more about hybrid yachts? Continue reading below:

What is the history of hybrid propulsion?

Hybrid propulsion in yachting has its origins in the 20th century, with some iterations of its usage seen as far back as one hundred years ago. However, it is only in recent decades that the idea of “Green Yachting” has become better understood and more widely applied in a luxury yacht setting. It is also worth noting that this technology is still very much evolving, even now, with new and more efficient systems constantly being developed. Most particularly noteworthy advancements are around battery systems, their capacity, and capabilities.

Key projects in the evolutionary process of hybrid superyachts included 96-metre Limitless, launched by Lürssen in 1997. But, it was the launch of the 58-meter sailing yacht Ethereal from Royal Huisman in 2009 that really caught the attention of the yachting world. Hailed as the world’s first true hybrid superyacht, Ethereal was the brainchild of discerning owners who were determined to create an energy-efficient and environmentally responsible sailing yacht, drawing on all the available technology at the time to do so. The 2015 83.5-meter Savannah, which launched from Feadship in 2015 was another significant milestone, with a pioneering hybrid propulsion package installed. The yard reported that Savannah’s five-option propulsion system delivered significantly reduced emissions together with a 30% fuel saving when compared to similar non-hybrid vessels.

Today, more and more hybrid superyachts are being launched and offered, with hybrid yachts of note including the one-of-a-kind 142.81-metre Sailing Yacht A, 50-metre HOME and 50-metre Electra from Heesen, 43-metre Canova from Baltic Yachts and 80m Artefact from Nobiskrug.

But what exactly is hybrid propulsion technology?

Put simply, hybrid propulsion technology is the use of two (or more) different energy sources to power a yacht, with the traditional engine source being supplemented by another source. Most often this means the use of a combination of diesel and electric systems. These power sources can then either be used individually or in conjunction with each other depending on the system installed. Hybrid propulsion technology is applicable on both sail and motor yachts and is optimized to suit the vessel in question to deliver the best and most efficient results.

The Details

Traditionally yachts are powered by a combustion engine that is powered by fuel. By contrast, a fully electric propulsion system makes use of a battery-powered motor. A hybrid propulsion system will feature a variable combination of a combustion engine, generators, battery packs and electric motors, dependent on the system. There are two primary types of hybrid systems: serial and parallel. Key differences between these two systems are in the relationship between the propeller and the engine.

Serial Hybrid System: This is where the main power source is an electric motor that is supplied by batteries, with an engine-driven generator on board to charge the batteries. When charged the electric motor will power the yacht, with the combustion engine shutting down. In a serial system, the engine and driveshaft are not mechanically connected. Often there will be the option for charging to also be powered by solar power, wind power, or shore power.

Parallel Hybrid System: This more versatile set up offers multiple options for operations, allowing users to easily switch between propulsion modes (whether electric or combustion engine). Unlike the serial set up, in a parallel system, the engine and driveshaft are connected directly, with the electric motor working on the same driveshaft. With this system, the traditional engine set up remains for when long periods of operations are required. The electric system can then be used as needed, dependent on the setting/conditions/requirements, with both systems able to work in parallel.

Because it is not directly connected to the propeller shaft, a serial system’s generator/electric motor must be able to handle the highest propulsion levels that the boat can achieve and is subsequently more powerful than a parallel system. While a serial hybrid system delivers clear improvements in efficiency (versus a conventional system) when operating at higher/optimum speeds, this set up can also mean situations where efficiency benefits of the hybrid system are potentially reduced when being used in low-speed operations such as harbor maneuvering.

In contrast, the electric elements of a parallel system need not operate at such high propulsion levels. The standard engine can be used for higher levels, while the electric motor will usually be used for when low to moderate speeds are required. The traditional engine will usually put to use for higher speeds and/or when the batteries are depleted, meaning that the most efficient form of operations is instigated as needed.

Which system to use, and the power levels, ranges, and efficiencies that are possible will depend on a number of variables including the type and use of the yacht, and owner preference. Whatever the type of system in use, the end goal is to deliver the most efficient operations possible, making use of all systems and of available electrical energy.

What are the advantages of Hybrid Propulsion?

The primary benefits of hybrid propulsion include efficient power use, allowing fuel to last longer, and for a yacht to run itself with more self-sufficiency due to a reduced reliance on engine power alone. The use of hybrid propulsion can represent significant savings on operational costs when compared to equivalent non-hybrid yachts. The versatility of a hybrid system also allows captains to operate yachts in the best and most efficient way dependent on the setting and operation requirements

That said, other key benefits that are of direct interest to the luxury yachting sector include quieter operations, due to the options of placing the more compact power sources away from guest areas, and a reduction of vibrations. Hybrid propulsion technology is essentially silent mode for your yacht. Much of the technological developments around hybrid have been client-driven, with more owners now seeking to experience yachting in a lower-impact manner, while enjoying the best and most comfortable on-board experience. When the yacht is in ‘silent mode’ guests can enjoy their surroundings more without the background noise of engines, and also enjoy a quiet night of sleep that is undisturbed by operational noise.

What are the environmental benefits of hybrid propulsion?

There are many environmental benefits to the use of hybrid propulsion and all these benefits are in line with the style of expedition and exploration yachts being built by Bering Yachts. Using a hybrid system lowers the yacht’s fuel usage, reduces emissions, increases efficiency, and allows the yacht to go further for less. It means greener yachting – something that is more important than ever as the world becomes more aware of the impact of fossil fuels and pollution and of individual carbon footprints.

For those cruising in marine reserves and pristine waters, the knowledge that the impact of their yacht can be kept to a minimum is often another priceless benefit. ‘Silent mode’ also delivers on an experiential front – there is something very special about enjoying a deserted anchorage without any disturbance. Equally, when in port the ability to not run off full engine power is extremely appealing.

With more and more destinations on the planet becoming protected zones, where diesel-powered vessels are not allowed to visit in order to protect these precious sites, the ability to cruise under electric power is certain to become increasingly appealing. From coral reefs to nature reefs, there are rising numbers of cruising grounds where soon only yachts with electric propulsion will be able to gain entry. For those owners who wish to see the world without restraint, this is an extremely important consideration when considering whether to invest in electric propulsion.