Transport for London (TfL) is still investigating the most appropriate option for this proposed ferry service, including matters such as propulsion. In line with the aspirations set out in my Transport Strategy, I expect the new service to be as environmentally friendly as practicable.
Based on its current analysis, TfL anticipates a hybrid solution where a generator provides power during emergency or extraordinary operations, but batteries are used for power as much as practicable. Further work is required, however, before a final decision and design.
TfL is planning to consult on the proposals in summer 2020, and will provide more detail on matters such as propulsion at that time.