Green yachts: paradox or possibility?

A luxury superyacht produces around 7,000 tonnes of carbon dioxide each year. While efforts to reduce the yachting industry’s environmental impact have progressed recently, the sector is not yet sustainable. So, what more can be done to improve yachting’s environmental credentials?

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With approximately 10,800 yachts afloat in 2022, around half of which are superyachts of over 30 metres, the combined CO? emissions significantly impact global temperatures.?

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But it’s not only CO? that presents a problem. Diesel-powered yachts produce nitrogen oxide (NOx), known to cause respiratory problems and acid rain. International Maritime Organisation (IMO) legislation limiting NOx emission levels has threatened the viability of superyachts since its 2021 introduction. While many marine vessels convert NOx into water and nitrogen using selective catalytic reduction (SCR), yachts’ lower average engine load reduces its effectiveness.

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To ensure a thriving and sustainable future for yachting, the industry must move away from fossil fuels. But how can this be achieved?

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More sustainable sailing ??

Industry decarbonisation has shown promise in recent years, with the number of electric boat listings more than doubling between 2021 and 2023. This includes an increasing number of tenders using electric propulsion systems to transport passengers between the port and the yacht.

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While decarbonising yachts is more challenging due to their size and range of facilities, the development of solar-powered yachts could be the solution.

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These yachts are propelled by solar-powered lithium-ion batteries. Some recent models have replaced Li-ion batteries with hydrogen fuel cells, offering improved energy density and range.

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However, these recent innovations encounter challenges such as:

-????? Other boats blocking light from the vessel while it is docked ??

-????? Reliability issues caused by the fluctuating power output of hydrogen fuel cells??

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Increasing reliability with resistors ??

Dynamic braking resistors (DBRs) help to tackle both problems. Solar panels can be positioned to follow the sun, but safe and precise positioning is only achievable by dissipating the excess energy generated by decelerating motors. Consequently, the panels experience less blockage from other ships and more solar energy can be converted to power the yacht.

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DBRs can also combat hydrogen fuel cells’ reliability issues. To ensure the yacht’s power requirements are always met even if the output oscillates, it is possible to install a fuel cell that exceeds these requirements. However, this option also requires a DBR to dissipate the excess energy when it is not needed.

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Cressall’s EV2 DBR offers an ideal solution, offering benefits such as:

-????? The ability to combine units to fulfil power requirements of up to 125 kW ?

-????? A water-based cooling system, making it lightweight and compact ?

-????? Ten kilowatts (kW) of power per cubic decimetre (dm3) and 9.3 kW of power per kilogram ?

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Yachting’s excessive emissions once made sustainable yachts seem like a paradox. However, supporting renewable innovations with resistor technology will finally make high-performance, low-emission yachts a possibility.?

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To discover how Cressall’s DBRs can support your marine application, visit the website.