Speaking during session three of the Offshore Support Journal Subsea Conference in London, DNV GL segment director, special ships, Arnstein Eknes said hybrid propulsion was a sound choice for ships that operate at low speeds
He based this on considerations of technology and efficiency and not economic factors. Mr Eknes said the economic reality might be different for companies. “What is economically viable is a different story.”
Speaking of innovations in hybrid vessels, Mr Eknes was optimistic the transition from petroleum-based engines to cleaner systems could be both cheap and environmentally sound.
Mr Eknes noted that most currently operational offshore vessels are not newbuilds but retrofits, making hybrids a natural choice, citing the fact that over half of operational vessels run hybrid systems.
Moreover, the various factors in an offshore vessel’s operation – waiting time, anchor handling, OSV operations – means it incurs high fluctuations in power demands. Mr Eknes said hybrid was a natural solution where big variations in power demands exist.
On the need for batteries combined with hybrid systems, he said vessels with DP2 and DP3 are not allowed to run on one engine alone. Further, he said, the load could be optimised.
With regards to subsea vessels, Mr Eknes stressed that suppliers who have transient consumers should consider hybrid systems because it could match consumer expectations of decarbonisation and emissions reduction.