Resilient Energy Systems for Arctic Offshore Wind: A Case Study for Icebreaking Offshore Wind Vessel

Abstract Ice conditions, low air temperatures, and remoteness affect offshore wind vessel functionality and operations. Cold climates and ice also have an impact on the economics of offshore wind installations and maintenance. The Nordic countries, and Estonia plan to build more than 5,000 offshore windmills, which need to operate year-round and during the ice season. The Finnish icebreaker Polaris is one of the most advanced ships in its class. Innovative designs were used for the vessel’s hull form and propulsion unit arrangement. The ship can use either liquefied natural gas (LNG) or low-sulfur diesel oil as fuel. Its propulsion system is based on Azipod® propulsion and applies a novel three-propulsion unit concept. A study was conducted to show how an Energy Storage System (ESS) could help improve the overall power efficiency of icebreakers, saving fuel and reducing emissions. In this case study, actual ice operation data and powerplant load profile from an icebreaker were used to simulate the effects of an Energy Storage System. The simulation indicated substantial benefits of ESS to both LNG and diesel operations. This paper will discuss the latest developments in smaller icebreaking offshore vessel technology, from the conventional power solution to the modern electric azimuth propulsion combined with the Onboard DC Grid™ and Energy Storage System (ESS). We will also discuss different ESS technologies to meet specific vessel and operational requirements. A specific focus will be on the vessels’ operating in ice conditions to meet performance and ice operation requirements. Any vessels with icebreaking operations demand high installed power and fast dynamic response, leading to high fuel consumption and significant power variations. At the same time, there is increasing demand for high energy efficiency and low emissions. An icebreaker with modern electric power and propulsion system, combined with ESS, is an ideal solution, as the ESS can be easily connected to the grid to maximize the ship’s performance and efficiency.