Rare Earths: Permanent magnet motors for electric ships in China

Miyun reservoir, China

In September 2019, two electric ships equipped with permanent magnet synchronous motors (PMSMs) were launched in Miyun reservoir, an inshore lake close to Beijing. As the reservoir is one of the main drinking water sources of Beijing, government clean water targets require that ships are equipped with electric motors to comply with low-carbon emission standards.

Roskill View

Rare earth permanent magnets motors are used mainly for light-weighting, improving efficiency and optimising performance. Automotive and aerospace industries are the key applications for PMSMs for these reasons. Roskill forecasts that, along with the rapid growth of electric vehicles over the 2020s, rare earth demand in magnets will increase in tandem as PMSMs play an important role in the drivetrain.

In electric shipping, such as those launched on the reservoir of Miyun, larger motor sizes usually mean more permanent magnets are consumed per motor. The Beijing fleet, while not restricted in size for the motors, benefits from decreased maintenance requirements and improved efficiency of the PMSM, similar to the benefits that drive offshore wind turbine use of direct drive permanent magnet generators.

Despite the larger motors, rare earth demand in shipping will be dwarfed by demand growth in automotive drivetrain. However, permanent magnet applications in shipping emphasise the importance to optimise energy consumption as a solution to clean energy and global energy demand.


Roskill will publish its 19th Edition of the Rare Earths: Outlook to 2029 in December 2019, which includes three updates that provide you with up-to-date supply, demand and price forecasts, along with profiles of major producers, processors and end-uses. Click here to download the brochure and sample pages, or to access further information.

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This article was written by Leslie Liang and Nils Backeberg. Please get in touch below if you wish to discuss further:

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