Permanent magnet (PM) shaft generators are being touted as a way to cut power demand and emissions on large containerships, particularly those resulting from plugging in reefer boxes to ship refrigerated goods.

Yaskawa Environmental Energy — a Finnish builder of PM shaft generators that is also branded as The Switch — has sold 100 PM generators for ships since 2014. They have been mainly used in large LNG and LPG carrier newbuildings, but have also been installed on product tankers and car carriers.