Offshore support vessels are increasingly being fitted with hybrid energy systems including batteries, and Eidesvik Offshore’s Viking Princess was the first time batteries were used to reduce the number of generators on an offshore ship. The new energy storage solution will improve engine efficiency, generate fuel savings and reduce greenhouse gas emissions.
Viking Princess completed sea trials with the hybrid energy storage system (ESS) and re-entered service with Eidesvik Offshore on 9 October 2017.
Wärtsilä said that with the hybrid system on board the platform supply vessel (PSV) there are “significant potential savings,” primarily due to the vessel’s operating profile being variable.
“When using the energy storage system on board Viking Princess, the fuel saving potential can be up to 30%, depending on the nature of the operation,” said the propulsion specialist. CO2 emissions can be reduced by 13-18% per year, depending on operational conditions and requirements, and the hybrid solution enables the engines to operate at a more optimal load. This means that the intervals between engine maintenance can be extended.”
Viking Princess now runs on a combination of power from a battery pack and three Wärtsilä engines that burn liquefied natural gas (LNG). The energy storage solution also provides balancing energy to cover the demand peaks, resulting in a more stable load on the engines.
Wärtsilä said the technology is like that used in hybrid vehicles: it prevents engine load from dipping and uses surplus energy to re-energise the battery, which can be charged as needed. A remote monitoring and operational advisory service from Wärtsilä supports the daily operation of the vessel ensuring efficient and optimised operations.
SolstadFarstad followed suit with the announcement in May that two of its PSVs, Normand Server and Normand Supporter, would be refurbished to operate on hybrid power systems, with 560 kWh batteries replacing a diesel generator on each vessel.
Class societies such as DNV GL have highlighted several other advantages of hybrid battery power, including significantly reduced fuel costs and emissions. Such systems can also significantly enhance responsiveness and safety when vessels are operating in high-risk situations.
In the past, Eidesvik has spoken of vessels fitted with batteries – although not in a configuration that eliminated a generator – as “even more responsive” with batteries on board, proving particularly advantageous in heavy weather.
DNV GL points out that batteries give a vessel “instantaneous access to power” that diesel systems cannot match. The class society believes other advantages will also become evident, such as the ability to store energy harvested from waste heat recovery, regenerative braking of cranes and/or forms of renewable energy such as solar energy. Another class society, Lloyd’s Register, said battery and hybrid technology can help with emissions compliance.
Interest in hybrid propulsion is evidently spreading beyond Norway and the North Sea, however, and Corvus Energy in February was confirmed as the supplier of a lithium ion-based Orca ESS for four PSVs owned by Seacor Marine’s Mexican joint venture Mantenimiento Express Marítimo SAPI de CV, known as Mexmar.
The refit was scheduled for completion by July 2018 and Seacor’s marine manager of engineering, Tim Clerc, said the company was keen to have such hybrid energy systems installed on more of its vessels, praising the technology’s dual benefits of being environmentally friendly and highly efficient.
Mexmar had previously announced, in September 2017, its OSV Seacor Maya was to be upgraded with a hybrid power solution designed by Kongsberg to meet strict environmental regulations by reducing CO2, NOx and SOx emissions, reducing operating costs through reduced fuel consumption.
Kongsberg was selected as sole supplier for the delivery, supply and integration of an ESS with a custom-designed energy control system. The ship’s existing K-Pos DP-22 dynamic positioning system and K-Chief 700 IAS automation system will also be upgraded. The upgraded K-Pos DP-22 system’s functions include power load monitoring and blackout prevention. The system will also display battery data including capacity and status.
Developments are also taking place among marinised battery suppliers. Akasol and Zem announced a partnership in 2017 to develop lithium-ion batteries for marine use. German company Akasol specialises in lithium-ion battery systems for a range of transport applications.
The German and Norwegian firms are developing fluid-cooled modular lithium-ion batteries that can be combined in modular fashion to meet the requirements of small vessels. The first fruit of their labour is the Akazem 15, a modular battery unit for workboats and small passenger ferries. June 2017 also saw Zem partner with French battery storage system provider Nidec to develop batteries for passenger vessel Vision of the Fjords, which has a 1.8 MWh battery system.
A number of Norwegian vessels contracted by Norwegian state oil company Equinor, formerly known as Statoil, are being retrofitted with hybrid battery systems. Among them is SolstadFarstad’s Far Sun, a diesel-electric PSV originally delivered to Farstad in 2014 by Vard.
SolstadFarstad and Vard Electro have co-operated to analyse the vessel’s fuel economy, consumption and emissions over a long period. Vard’s SeaQ ESS, which will be installed on the vessel, will have an additional benefit of providing greater redundancy, acting as a ‘spinning reserve’. Vard Electro is responsible for the project, including engineering, steel prefabrication, installation, integration, testing and commissioning. The ship will be awarded the class notation Battery Power by DNV-GL. Working closely with SolstadFarstad, Vard Aukra and Vard Electro have developed a standardised solution with an additional deckhouse which complies with regulations and is well suited for this type of upgrade, for offshore vessels, ferries and other vessels. Vard Aukra has been awarded a contract for the manufacture, integration and installation of deckhouses and other equipment on board. The battery supplier will be Corvus in Bergen.
In October 2017, PBES secured type-approval of its ESS for use in commercial marine, offshore oil and gas and renewable energy applications from DNV GL. The PBES ESS makes use of the company’s patented CellCool cell-level liquid cooling, ThermalStop anti-propagation barrier, E-Vent gas venting system and CellSwap battery re-coring, and is designed to integrate seamlessly with all types of power generation in a variety of commercial and industrial applications.
Rolls-Royce developing cradle and rail-based boat transfer method
Rolls-Royce Marine is developing an innovative cradle and rail-based method for launching and recovering daughter craft, called the boat transfer system (BTS) with interesting potential applications aboard OSVs.
The system utilises a cradle that a daughter craft simply manoeuvres into before being raised up to deck level on rails. Daughter craft can then either be taken on board or simply held alongside to allow for transfer of people and equipment at deck level. The modular cradle will be fitted with two dampeners to keep daughter craft stable during the process.
Deployment is either via a knuckle boom or an overhead crane and the system is available in ‘heavy-duty’ and ‘light’ versions.
Rolls-Royce Marine sees a number of advantages of the BTS over traditional davit and wire-based methods of deployment, including no pendulum effect from long wire lengths, no painter-handling hazards, no dual-lift complications, no hazards from free-swinging hooks and no hazards from misplaced cargo.
As well as heavy-duty and light versions for use in recovering and launching varying boat sizes, Rolls-Royce announced a frequent-use version for work in areas such as around offshore oil and gas installations, windfarms, commercial exploration vessels and naval vessels is in development alongside an occasional-use version for standby rescue vessels. The cradle can be fitted with a net to assist in recovering people from the water.
The BTS is targeted to compete with high-end davit systems for vessels of 60 m plus, and will take up slightly more space than a single-point davit system.