Hybrid-electric propulsion is becoming a key component on newbuilds, while some owners are also adding batteries to LNG-fuelled OSVs
When it comes to electrification, offshore support vessels have been pioneers in the maritime sector, adopting energy storage technology to improve fuel consumption, reduce emissions and provide additional safety. And the uptake of batteries is only expected to accelerate in the years ahead.
“Offshore supply vessels were among the first movers,” said DNV GL – maritime, business development manager Christos Chryssakis. “Almost all new vessels are ordered with batteries, mainly as hybrid configurations, and charterers are asking everyone to prepare for future upgrades.”
Mr Chrysassis made his observations at Riviera Maritime Media’s Offshore Support Journal, Middle East Conference in October. Joining Mr Chrysassis on a panel titled, ‘New design concepts and innovative technology solutions,’ DNV GL segment director, OSV and special ships Arnstein Eknes, elaborated on the trend. “The degree of hybridisation is increasing. Most of the battery systems and installations on offshore vessels are conversions. This is a trend that will continue and strengthen in the years ahead,” he said.
Why does he see a strengthening of electrification in the OSV sector? “Simply because the batteries are acting as a lubricant to reduce your fuel consumption, reduce emissions, and to make sure that you have a more robust vessel,” said Mr Eknes. “Actually, a safer vessel, because it’s responding. You don’t need to produce the power, you have it,” he added.
Mr Chryssakis said the uptake of batteries and alternative fuels by the maritime industry as a whole was clearly evident when you analyse the newbuild order book.
While less than 1% of the existing fleet uses alternative fuels, mainly LNG and batteries, almost 10% of the newbuilds on order will use non-traditional fuels.
“What we see is a big change happening as we speak,” said Mr Chryssakis. “Owners are much more interested in using alternative fuels.”
In particular, Mr Chryssakis noted the growing interest in LNG as a fuel in shipping to help meet current greenhouse gas and CO2 emission reduction goals.
“LNG is playing a major role, but battery technologies are also quite significant, with other fuels such as ammonia, hydrogen, methanol and LPG,” he said.
Based on DNV GL data, he expects the number of LNG vessels to roughly double in the next two to three years. “However, the fuel consumption of these vessels is going to increase by four to five times in the same period,” he said. “This is because there will be much larger vessels – oceangoing ships - using LNG as fuel, and this is also helping to build the bunkering infrastructure for LNG in major shipping hubs. In turn, this will allow smaller vessels to take advantage of this growing infrastructure,” he added.
There are 22 OSVs that use LNG a fuel and 15 more under construction.
Some OSV owners are layering battery technology with LNG to achieve even higher emissions reductions. One such owner is Norway’s Eidesvik Offshore, which has refit the LNG-fuelled Viking Princess with batteries for its charter to Wintershall Dea.
Another is Louisiana-based, LNG pioneer Harvey Gulf International Marine (HGIM) which is burnishing the environmental credentials of its fleet further, refitting 10 of its OSVs with battery systems. This investment covers all five of its LNG-powered OSVs, led by Harvey Energy – the first LNG-battery hybrid retrofit platform supply vessel (PSV) in the Americas.
Following sea trials of Harvey Energy, Wärtsilä placed an order with Canadian-Norwegian battery provider Corvus Energy for four Orca energy storage systems (ESS) for HGIM vessels.
The reasoning behind this decision, according to HGIM chief executive Shane Guidry, is straightforward: clients and investors are increasingly demanding energy efficiency and emissions reduction. Mr Guidry said: “This fleet of vessels will be crucial in assisting our clients’ efforts to achieve net carbon zero, and we will continue to listen to them and invest in technology that will assist with their goals.”
Wärtsilä will integrate the battery-based ESSs, each with a capacity of 745 kWh, into its LNG-fueled hybrid-electric propulsion system. The ESS and Wärtsilä Energy Management System (EMS) will allow the vessels to operate in dynamic position mode on a single engine augmented by battery power, to operate more efficiently in transit and other operational modes, and to operate on battery power only when stationary.
“Almost all new vessels are ordered with batteries, mainly as hybrid configurations”
The four LNG-battery hybrid vessels – Harvey Liberty, Harvey Power, Harvey Freedom and Harvey America – will be fitted with the 1,100VDC – 745 kWh ESSs in 2021 and are expected to go into service in early 2022.
Other vessels expected to be fitted with battery systems include PSV Harvey Champion and its sister Harvey Supporter, as well as Harvey Hawk and Harvey Condor.
The MPSV Harvey Subsea will be fitted with two battery systems, making it the only dual-fuel battery-powered MPSV in the Americas.
Under a long-term contract with an oil major in the US Gulf of Mexico, privately held Edison Chouest Offshore (ECO) is adding an onboard battery system to an ECO 312-foot class PSV with options for additional systems.
Another battery-hybrid refit is being undertaken by Wärtsilä in Brazil, where the PSV CBO Flamengo will be converted to comply with DNV GL’s ‘Battery Power’ class notation. Brazilian owner CBO anticipates being able to operate safely on fewer engines at higher loads. The hybrid system will provide reserve power and reduce intermittent load increases – peak shaving – saving fuel and lowering exhaust emissions. Additionally, since the engines will operate for fewer running hours, maintenance requirements and costs will be reduced. CBO will handle the integration and installation of the hybrid battery technology once it is delivered in April 2021.
Upgrades for three Norwegian OSVs
Two 2008-built, Norwegian-owned light offshore construction vessels will be retrofit with hybrid electric systems, while a third vessel will be upgraded with a shore power system.
Following the upgrade, Østensjø Rederi’s OCVs Edda Fauna and Edda Flora will reduce the usage of their engines, with correspondingly lower levels of exhaust emissions while operating in dynamic positioning (DP) mode, and will also lower emissions levels in all other operational modes.
Meanwhile, Østensjø Rederi’s 2013-built PSV Edda Ferd is to be upgraded with shore power. “We are seeing more and more shore power facilities in ports everywhere we go,” said Østensjø Rederi chief project officer Egil Arne Skare. “We must be part of that development,” he said, adding the environmental benefits are 100%, provided that the shore power is supplied from a renewable source.
Each of the OCVs will be retrofit with an integrated hybrid power module from Wärtsilä, with a new electronic DC bus-link, allowing a vessel to operate in DP2 and 3 modes with a closed DC bus in hybrid, and an open bus on the AC system. The reduced running of the engines saves fuel and lowers the carbon footprint, while engine maintenance requirements are also alleviated.
“We intend to be a shipping company that leads in sustainable operations,” said Mr Skare.
Other Norwegian OSV owners are securing long-term charters thanks to their electrified vessels. Havila Shipping will supply two PSVs, Havila Foresight and Havila Charisma, that feature batteries and shore power connections, under a three-year charter agreement with Equinor. The PSVs are part of a fleet of supply vessels supporting Equinor’s operations on the Norwegian continental shelf. All vessels on long-term contracts for Equinor – about 20 vessels – have, or will have, a battery and a shore-power system by the end of this year.