Recent months have seen further important developments in hybrid energy systems for offshore support vessels with a platform supply vessel in which a hybrid power system replaced a generator and support for battery power from the NOx fund
As highlighted by OSJ on a number of occasions a growing number of vessels are being fitted with hybrid energy systems including batteries. However, a recent retrofit project on Eidesvik Offshore’s Viking Princess was the first time that batteries had been used to reduce the number of generators on board 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 new hybrid energy storage system and re-entered service with Eidesvik Offshore on 9 October 2017.
Highlighting the advantages of the concept, Wärtsilä said that with the hybrid system on board the platform supply vessel (PSV) there are “significant potential savings,” primarily as a result of the fact that the operating profile of a supply vessel is very 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 up 13-18% per year, depending on operational conditions and requirements, and the hybrid solution enables the engines to operate at 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 new energy storage solution also provides balancing energy to cover the demand peaks, resulting in a more stable load on the engines.
Wärtsilä says the technology is similar to 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.
Class societies such as DNV GL have highlighted a number of other advantages of hybrid battery power. They include the fact that they can significantly reduce fuel costs and emissions. In addition, hybrid systems with batteries can significantly enhance responsiveness and enhance safety when vessels are operating in safety-critical situations.
In the past, Eidesvik has spoken of battery-assisted vessels, such as Viking Lady, to which it also fitted batteries although not in a configuration that eliminated a generator, as “even more responsive” with batteries onboard. This proved to be particularly advantageous in heavy weather.
DNV GL points out that batteries give a vessel “instantaneous access to power, when it’s needed,” and that “diesel engines can’t give you that instantaneous response.” The class society believes that in the long run 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, has spoken of the ability of battery and hybrid technology to help shipowners overcome the challenges of emission regulations.
In November 2017, the NOx Fund in Norway launched a support programme for owners wishing to retrofit vessels that are on long-term contracts with hybrid energy solutions based on the use of batteries. The application deadline for owners is 30 June 2018, provided that there are still funds available under the support programme.
Under the scheme a PSV will be eligible to receive a NKr 5Mn to support retrofitting battery power. It is also providing additional support in the form of NKr4/kWh when batteries are charged using shore-based power using so-called ‘cold ironing’ in order to stimulate ‘plug-in’ solutions.
To be eligible for support by the NOx Fund’s hybrid power programme, a vessel applying for retrofit must already have engines burning LNG or a selective catalytic reduction (SCR). The batteries installed must have sufficient capacity to enable more efficient operation of the ship’s diesel engines, including peak shaving and acting as a spinning reserve.
Vessels must be able to provide documentation demonstrating that they are contracted for work on the Norwegian continental shelf (NCS) for a period three years or more. Companies that apply for the support that are in the tender phase for contracts on the Norwegian NCS will only receive support if they secure a contract. Companies that have already installed batteries will not be eligible for support.
The NOx Fund has allocated NKr 100Mn to the support programme. “These are measures that are desired both by the offshore vessel companies and the oil companies, but that there is a need for predictable support for retrofitting battery packs,” said the NOx Fund’s managing director, Tommy Johnsen. “This support programme should make it easier for companies to predict what support they can expect and that these measures will significantly reduce operating costs,” he said.
A growing number of suppliers are recognising that there are now opportunities for them to provide hybrid power systems for offshore vessels. Among them are Pon Maritime companies Bakker Sliedrecht, Pon Power Bolier and EST-Floattech, who joined forces to introduce hybrid solutions at the Europort 2017. Together, they are offering the market propulsion and energy storage solutions that combine diesel engines, energy storage and systems integration.
“A wide range of sectors are demanding ever-cleaner power and propulsion systems,” said Pon Maritime. “Following recent trends in the automotive industry, the maritime sector has recognised that hybrid solutions are the wave of the future: diesel when necessary, fully-electric when possible, and often a combination of the two.
“As more and more companies become aware of the need to reduce carbon emissions, and regulations become increasingly strict, hybrid propulsion provides a sound business case for the future, the company said.
“The benefits of a hybrid solution are manifold: it reduces operational expenses and emissions, while improving overall performance. Collaboration among Pon’s maritime companies has resulted in a comprehensive solution that also offers a reliable partner for service and maintenance. By combining their efforts, we can deliver a highly integrated hybrid system for a wide range of ship types.”
Interest in hybrid propulsion is evidently spreading beyond Norway and the North Sea, however, and MEXMAR, Seacor Marine’s joint venture in Mexico, recently announced that it is to upgrade the vessel Seacor Maya with a hybrid power solution designed by Kongsberg, in order to enable the vessel 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 energy storage system with a custom-designed Energy Control System (ECS). 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 the companies that supply marinised batteries into the market. Earlier this year, Akasol and Zem announced a partnership to develop lithium-ion batteries for marine use. A German company, Akasol specialises in lithium-ion battery systems for a range of applications such as buses and trains.
Together, 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 work together 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 a new passenger vessel, Vision of the Fjords, which will have a 1.8 MWh battery system.
Although not currently supplying batteries for offshore vessels, Saft is supplying two Seanergy lithium-ion battery systems to Rolls-Royce Marine for integration into the hybrid propulsion system on the polar research vessel RRS Sir David Attenborough. The new vessel is due to enter service in 2019 it will carry out oceanographic and other scientific work in the Antarctic and the Arctic, as well as transporting supplies to Antarctic research stations. The Rolls-Royce diesel-electric propulsion system will be powered by the new Bergen B33:45 engines that will operate in combination with two Saft lithium-ion batteries. Fully integrated into the vessel’s control and automation system, the batteries provide a combined 1,450 kWh capacity. They will help deliver the peak power required by the vessel, such as when operating in a dynamic positioning mode.
As also recently highlighted by OSJ, a number of Norwegian vessels contracted by Norwegian state oil company Statoil are being retrofitted with hybrid battery systems. Among them is Solstad Farstad’s Far Sun, a diesel-electric PSV originally delivered to Farstad in 2014 by Vard.
In close cooperation, Solstad Farstad and Vard Electro have analysed the vessel’s fuel economy, consumption and emissions over a long period of time. Vard’s SeaQ energy storage system, which will be installed on the vessel, will have an additional benefit, 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 Farstad, Vard Aukra and Vard Electro have developed a standardized solution in way of an additional deckhouse which complies with regulations and is well suited for this type of upgrade, of 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, another well-known supplier, PBES secured type approval of its energy storage system for use in commercial marine, offshore oil and gas and renewable energy applications from DNV GL. The PBES energy storage system 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.
SSPA highlights potential advantages for DP ships
SSPA in Sweden, which provides ship design and energy optimisation among its range of services, has also highlighted growing interest in hybrid energy storage systems that make use of batteries. It says developments in battery technology are partly responsible for increased interest from the shipping industry, along with the potential to reduce operating costs and reduce greenhouse gas emissions.
“Battery applications have recently become interesting in relation to some large-scale marine applications. This is due to a combination of factors such as developments in lithium ion batteries, giving improved capacity, reliability and reduced prices, alongside uncertainties in relation to fuel costs, fuel supply and stricter emissions legislation.
“For vessels with dynamic positioning, battery hybrid installations have become a competitive alternative for newbuilds as well as retrofits,” said SSPA. “High demands on system redundancy for dynamic positioning applications require multiple engines. This results in low engine loads and high engine hours, hence less efficient operation and high maintenance costs.”
However, as it notes, when batteries are installed one or more engines can be switched off with redundancy demands fulfilled. “This leads to increased efficiency for vessel operation,” it said.