(3 p.m. BST) -- Hurtigruten is expanding its hybrid-powered fleet by adding green technology to MS Trollfjord, MS Finnmarken and MS Midnatsol as part of a major renovation project, set to be completed in 2021.

The three ships will be renamed as part of the transformation; MS Trollfjord will become MS Maud, MS Finnmarken renamed MS Otto Sverdrup and MS Midnatsol renamed MS Eirik Raude.

The ships will be fitted with battery packs to allow the engines to operate using hybrid power. Shore-powered equipment will also mean the ships can operate using only battery power when docked in ports with shore power facilities -- cutting emissions to zero.

Among the updates set to transform the three ships, all cabins and suites will be renovated, with new suites added, and all public spaces will be redesigned.

The main restaurants will become Restaurant Aune and a new specialty venue, Restaurant Lindstrom, will offer modern Norwegian cuisine. Fredheim will serve as the ships' more informal dining venue and a new outdoor grill will also be introduced.

The ships will also get a new wellness area with gym, lounge and treatment rooms; an Expedition Launch (the tender area) and Science Centres will be added, while the pool area on MS Otto Sverdrup and outdoor hot tubs on MS Maud and MS Eirik Raude will be upgraded.

Hurtigruten CEO Daniel Skjeldam said: "With these new expedition cruise vessels, you will be able to explore Norway like never before, with all the comforts, facilities and expertise you need for creating a perfect adventure. Combined with groundbreaking green technology, these ships will truly stand out."

MS Finnmarken will be the first ship to be retrofitted with battery packs in 2020, with Hurtigruten revealing it has a letter of intent for the same updates for MS Trollfjord and MS Midnatsol in 2021. 

Hurtigruten's Roald Amundsen, which launched in July 2019, became the world's first cruise ship to operate using hybrid-powered engines.