The technology group Wärtsilä has extended its long-held lead within the field of hybrid electric vessel systems. Recent figures from Clarkson’s Research show that there are currently more than 300 hybrid vessels delivered or on order. Wärtsilä has delivered and received orders for 70 vessels as of 13 May 2022 and this number continues to increase – with a current market share of over 20%, and a combined installed battery capacity surpassing 100 MWh.A hybrid vessel propulsion system typically combines engines and batteries, so when compared to diesel-mechanical or full electric vessels, hybrid vessels are considered to be more complex. Using energy storage allows for lower installed engine power, resulting in lower fuel use – critical when considering more expensive clean fuels – as well as reduced emissions and better EEXI and CII ratings. The availability of multiple power sources also offers operational flexibility, including running fully electric for extended periods depending on battery capacity.Two important elements of hybrid vessels are the ability to integrate multiple vessel systems and real-time optimisation of the on-board energy system. Wärtsilä combines a wide range of system expertise across a broad range of ship power and propulsion machinery with unparalleled hybrid integration expertise, honed across multiple vessel installations and at its dedicated Hybrid Centre in Trieste, Italy.Wärtsilä’s large installed base of hybrid vessels in operation also feeds into its proprietary energy management system, which dynamically optimises the onboard energy system depending on the operational mode and environment.Typical functions for hybrid vessels include spinning reserve to provide emergency power in case of blackout; peak shaving to keep engines running at optimal load; full electric manoeuvring to comply with port emission regulations; and dynamic load taking to reduce the time it takes for vessels to start up and reach a required speed.