Battery powered ships

SAFER, SMARTER, GREENER

MARITIME

– a guide to use of batteries in shipping

IN FOCUS –THE FUTURE IS HYBRID

02 IN FOCUS The future is hybrid

ACKNOWLEDGEMENTSThis publication was made as a part of a joint project between ZEM represented by Egil Mollestad, Grenland Energy represented by Lars Ole Valøen and DNV GL.

The work was made possible thanks to financial support from Transnova, now ENOVA.

Editorial committee: Gerd Petra Haugom, Magne A. Røe and Narve Mjøs, all DNV GL. Produced by DNV GL Maritime Communications.

www.dnvgl.com/maritime/advisory/battery-hybrid-ship-service.html

Seatrade Awards is the “Oscar of shipping” and the annual event takes place at the prestigious Guildhall in London. In the category Clean Shipping the battery powered ferry Ampere was the winner. Sigvald Breivik from Norled accepted the award on behalf also of Fjellstrand Shipyard and DNV GL.

Left to right: Mary Bond, Managing Director, Publishing Seatrade, Editor, Seatrade Cruise-Review & Seatrade Insider, UBM EMEA; The Lord Mountevans, Chairman of Maritme London and Maritime UK and a Director at Clarksons; Mr Sigvald Breivik, Chief Technical Officer, Norled on behalf of Norled, Fjellstrand Shipyard and DNV GL; His Highness Sheikh Mohammed bin Maktoum al Maktoum, Deputy Head of Mission and First Secretary of the UAE Embassy (receiving the award on behalf of Drydocks World – Dubai); Koji Sekimizu, Secretary-General, IMO; Chris Hayman, Chairman, Seatrade.

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The future is hybrid IN FOCUS 03

04 ................EDITORIAL06 ................... THE FUTURE IS ELECTRIC AND USING BATTERIES WILL BE PART OF THE SOLUTION

08 ...............BATTERIES TODAY08 ...............Overview of use of batteries in ships

10 ...............Battery capabilities

12 ...............Power systems with batteries integrated

15 ...............Power supply for batteries in shipping

16 ...............Battery hybrid ships

18 ...............BATTERIES TOMORROW22 ................. Innovating for batteries

24 ...............The ReVolt – a new, innovative ship concept

28 ...............WITH BATTERIES TOWARDS THE TWO-DEGREE TARGET30 ...............GREEN COASTAL SHIPPING: NORWAY – A SHOWCASE FOR GREEN SHIPPING34 ...............ALTERNATIVE FUELS FOR SHIPPING38 ...............BATTERIES – THE RIGHT OPTION?38 ...............Battery Ready Service

42 ...............ENVIRONMENTAL AND SOCIAL ASPECTS44 ...............STATIONARY ELECTRICITY STORAGE 46 ...............EXPERIENCES – HYBRIDIZATION WITH BATTERIES46 .................Operation of a hybrid crane

48 .................Viking Lady – real-life ship performance results

52 ...............BATTERY FERRIES, A CRAZY IDEA?

54 ...............HIGH SPEED CRAFTS 56 ...............REQUIREMENTS FOR BATTERY SYSTEMS56 .................DNV GL Guideline for Large Maritime Battery Systems

58 .................DNV GL Battery rules

61 .................DNV GL classed battery electric and battery hybrid vessels

62 .................Safety Issues – a safe installation

64 .................Service life assessments

66 ...............MARITIME BATTERY FORUM

CONTENTS

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EDITORIAL

Recent developments in battery technology and ship electrifi-cation hold significant promise for more efficient use of energy, energy recovery and use of renewables.

All electric ships and hybrid ships with energy storage in large batteries with optimised power control can significantly reduce fuel costs, maintenance and emissions. Additionally, increased ship responsiveness and improved regularity and safety in critical situations are obtained. Power generation units can be smaller or fewer and optimised for a more average (not peak) load, and thereby reducing investment costs. Batteries can store energy harvested from waste heat recovery, regenerative braking of cranes and renewable energy. Additionally, they can improve propulsion systems based on LNG and other environ-mental friendly fuels and improve the performance of emission abatement technologies.

Major maritime power system providers are now offering new battery based solutions. The last year DNV GL trained more than 100 participants in our introduction course to maritime battery systems. We facilitated the establishment of the Maritime Battery Forum that already has 45 members from cargo and ship owners, yards and vendors as well as governmental agencies. Furthermore, DNV GL has established Green Coastal Shipping Program with the vision to establish the world’s most effective and environmentally friendly coastal shipping though enhanced public-private collaboration.

We are at an early stage with battery powered ships. There is a large interest among stake holders and the number of ships

Batteries represent a new component in the power solution with attractive properties producing benefits, such as reduced costs and emissions, improved ship performance and safety.

Narve Mjøs, Director Battery Services & Projects


with battery technology is rapidly increasing world-wide. In Norway, financial support for realization of electric and hybrid ships can be made available from sources such as Innovation Norway, Enova and the NOx-Fund.

Battery powered ships in various segments need validation of economy, safety and reliability.

As this is successfully achieved we will see a signifi-cant market penetration and thereby large environ-mental savings.

At DNV GL we believe that the ground work has been laid for batteries to thrive in the shipping and offshore sectors – and we invite you to come and take the next steps together with us.

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DNV GL has established the full range of tools and of services to assist our clients to develop both new-build and retrofit hybrid and battery solutions. Examples are our Battery Rules and the Battery Guideline. We offer Battery Ready services, type approval and classification, technical/economic analyses, risk analy-ses, battery service life and optimisation analyses, ship performance instrumentation, measurements and analyses, technology qualification and hardware-in-the-loop testing of Battery Management Systems.

FACTS


THE FUTURE IS ELECTRIC AND USING BATTERIES WILL BE PART OF THE SOLUTION

In your view, how can battery propulsion systems become more competitive?

Batteries have dropped in price by some 60–70% in the past four years and my guess is that this trend will continue – with as much as a 50% reduction in price compared to the current level. This means that battery propulsion is a good and often viable solution to reduce CO2, SOx, NOx and particulate emissions. Full-electric solutions must be periodically recharged; they may be applicable, for example, for ferries, smaller cargo vessels and inland water transport. The impact that a solution like this has in reducing emissions depends on the source of electrical power – if the power is produced by renewable energy sources like hydro, wind or solar, the environmental gains are considerable.

“Regulators are introducing stricter controls to reduce SOx, NOx and particulate emissions in order to limit air pollution. In addition, there is more public awareness of climate change and increased public expectation that global CO2 emissions will be reduced. For the first year ever, global CO2 emissions did not increase in 2014 – so maybe we are all on the right track. However, much greater action on a much larger scale is still required if we want to prevent global warming rising above 2°C. DNV GL is well positioned and committed to drive the industry forward to become safer, smarter and greener. A lot of the answer lies with efficient and low-carbon technology,” says Remi Eriksen, DNV GL Group COO and Deputy CEO.

Remi Eriksen, DNV GL Executive Vice President and Deputy CEO


What about battery hybrid solutions in combination with LNG?

Battery hybrids have several advantages too, since they enable the vessel engine to run at more favour-able loads. This reduces fuel consumption and therefore emissions to air. Further benefits include an improved response time in safety-critical operations, an extended engine lifetime, less maintenance and less noise and vibrations.

Who is driving the technology?

I would claim that this is the car industry. To stay com-petitive, the car industry must come up with solutions that meet much stricter environmental requirements as well as satisfying increasing consumer require-ments. And for consumers, flexible solutions are important. Battery power has come a long way and the range of car batteries has improved significantly over the past five years; in addition, battery solutions are becoming cheaper and last much longer than they did just a few years ago.

The DNV GL tagline is Safer, Smarter, Greener. How is DNV GL positioned to work with the industry to come up with better solutions for the future?

We have the perfect setup for this in our company. We have the largest number of classed vessels running on LNG and batteries, we have class rules for this, we have an industry best practice guideline and we have been involved in joint industry projects, including solutions for offshore installations. We use considerable resources – in terms of both funding and personnel – to try to solve industry challenges, combining our maritime, oil and gas and power and transmission expertise.

I hope you enjoy reading this publication focusing on battery solutions for the shipping industry! The contents underline our view here at DNV GL: The future is electric – both literally and figuratively.

Author: [email protected]

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OVERVIEW OF USE OF BATTERIES IN SHIPS

The first golden age of electric-powered boats was in the period from 1890 to 1920, at which time petrol-driven motors became dominant. The Bergen Elektriske Færgeselskap (BEF) company was founded in 1894 and a fleet of small electric passenger boats started to operate in Bergen harbour. The last boat with electric propulsion was converted to use petrol and later diesel in 1926. However, the circle is now closed as the new all-electric ship the Beffen will start to operate in 2015.

It is the huge development in lithium-ion batteries over the past few years and, in particular, the adop-tion of high-quality batteries for electric and hybrid vehicles and large-scale grid systems that have now made battery systems a viable option for maritime applications.

Canadian-based company Corvus Energy, estab-lished in 2009, has been a pioneer in the maritime market for battery systems. The FellowSHIP research programme, headed by DNV GL, ordered the first big battery system from Corvus Energy for a hybrid installation on the Eidesvik-owned offshore supply

vessel Viking Lady. The 500kWh battery was installed in 2013 and an extensive monitoring programme has produced valuable efficiency and emission data well documenting the benefits of battery systems in such an application. The first new-built offshore supply vessel with a battery system installed was the Østensjø-owned Edda Ferd that was put into operation in the autumn of 2013.

One of the first offshore vessel to install a battery energy storage system as a commercial retrofit solution will be the Eidesvik vessel Viking Queen. The commercialization of this ground-breaking technology has been greatly facilitated by the R&D project FellowSHIP, where the partners have worked on bat-tery technology for five years. The initiative has been made possible by targeted cooperation between Eidesvik and Lundin Norway AS, which has the vessel on hire. The batteries will be supplied by ZEM AS.

In the ferry segment, several ships (both newbuild and retrofit) have been equipped with large battery systems in a hybrid configuration. The biggest instal-lation so far is the 2.7MWh battery system installed on

Electric propulsion of ships is not a new invention. The first electric powered boat we know about was a 24-foot boat in St. Petersburg in 1839 that could carry 14 passengers at a speed of 3 knots.

BATTERIES TODAY


Eidesvik will install a 650kWh/1.6MW battery system on board the Viking Queen. This will be one of the first offshore vessels to have such a system installed as a commercial retrofit solution, showing that it is possible for existing vessels to achieve a significant reduction in emissions too.

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Scandlines’ Prinsesse Benedicte, the ferry operating between Shælland in Denmark and Puttgarden in Germany. The Prinsesse Benedicte’s three sister ships have now also been equipped with similar battery systems.

The first large-size all-electric battery-powered car ferry, Norled’s Ampere, came into operation in January 2015. This 120-car and 350-passenger ferry is equipped with a 1MWh battery system. Quick charging takes place during the 10-minute period

between each trip and at night time. The Norwegian parliament has decided that all new invitations for ferry tenders in Norwegian waters shall if possible request zero- or low-emission propulsion technology. Based on this decision, a number of new all-electric or hybrid-battery ferry projects are expected in Norway in the next few years.

Authors: [email protected], [email protected] and [email protected]


BATTERY CAPABILITIES

The battery cells are made in different form factors, such as cylindrical, prismatic and pouch, and come in all sizes, from the small cells primarily made for consumer electronics to large sizes targeting heavy commercial applications. The maritime-focused systems have mainly been based on Li-ion cells with NMC (Nickel Manganese Cobalt Oxide) cathodes and graphite anodes. Systems based on iron-phos-phate cathodes have also been used. Both the NMC and iron-phosphate chemistries represent a good compromise between the most important parame-ters of safety, energy, power density, cycle life and cost.

Battery cells are today produced to a high-quality standard and it is very seldom that cells from quality producers experience any problems. The electronic control system that is required has also matured and the industry knows how to install large battery sys-tems in a safe and reliable way on board ships.

Huge battery-cell production facilities have been built over the past few years to supply the automo-tive needs. In addition, energy-storage systems for frequency regulations and peak shaving for grid installations have added significant volumes to the battery market. Technical developments, higher production volumes and tough competition in the market have resulted in the cost of battery systems

falling. As volumes increase in the maritime battery market, the cost of such systems is also expected to decline.


During the last ten years, a variety of lithium-ion based batteries has been devel-oped. Batteries have been optimized for energy density, power density, cycle life, cold weather performance, robustness, safety and cost.

BATTERIES TODAY

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Initial work on Li based rechargeable batteries, original patent for LiCoO2 in 1979 by John Goodenough.

LiMn204 intercalation demonstrated.

LiFePO4 intercalation demonstrated.

Commercial introduction of NMC battery chemistry in EV and PHEV.

High Power Li-ion for power tools: Sony, E-One Moli Energy, A123.

Maritime usage of NMC based Li-ion batteries for hybrid operation.

First demonstration of a Li-ion battery in the laboratory.

First mass production of Li-ion battery cell, 18650 LiCO2-Soft carbon for Sony TR-1 camcorder.

Long life EV batteries based on NMC chemistry.

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POWER SYSTEMS WITH BATTERIES INTEGRATED

Onboard ships, there is traditionally an electrical power system for the “hotel load” and the auxiliary systems. The propulsion power is taken care of by a combustion engine, called the main engine. The power for the electrical load is produced by gener-ator sets consisting of an electrical generator driven by a combustion engine. These engines are called auxiliary engines.

Ships that also use the electrical power for propul-sion are becoming more and more common today. Ships with operations that require variable power demand (such as offshore supply vessels) or flexible spaces (such as cruise vessels) are typical ships that use electrical propulsion.

Mechanical propulsion with battery hybrid electrical power plantThe figure on the right shows a battery integrated into the electrical system of a vessel with traditional mechanical propulsion.

In this case, the battery will be effective for smooth-ing the connected electrical load and helping to handle large load steps. When the large load steps are reduced, the number of auxiliary engines may also be reduced.

In cases where the load can regenerate power, such as in cranes, the battery can be used to harvest this energy.

This article describes different topologies that can be used on board ships with batteries integrated into their electrical power systems.

Mechanical prupolsion with battery hybrid electrical power plant

Electrical load

BATTERIES TODAY


Hybrid battery propulsionThe next figure on the right shows batteries integrat-ed into a power system for electrical propulsion.In this case, the battery will provide power to the large propulsion motors. The vessel may run on just batteries, just generator sets or in parallel operation using both batteries and generators.

In addition to being a source of energy for propul-sion, the batteries will smooth the load variations on the generator sets. The introduction of such a battery hybrid system will reduce the noise and vibration levels on the ship.

The topology can also facilitate the use of zero emission operation when entering a harbour.

Hybrid battery propulsion, with distributed batteriesOne challenge involved in the electrical propulsion concept is its efficiency. As seen in the previous figure, the system has several power converters and each of them typically represents a 2% power loss. If the batteries are distributed into the propulsion converters, the losses are reduced, see the figure on the right.

Another benefit with the distributed battery con-cept is that each propulsion unit is independent of a common source of energy. This might be a smart solution for vessels that require a highly reliable pro-pulsion thrust, such as redundant dynamic position-ing vessels (DP2 and DP3).

Hybrid battery prupolsion

Hybrid battery prupolsion with distributed batteries


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Hybrid battery, electrical, mechanical prupolsion and dc distribution

Hybrid battery, electrical, mechanical propulsion and DC distributionThe figure on the right shows a power system with an electrical/mechanical hybrid solution, a battery hybrid with plug-in possibilities and a DC distribution.

With a DC-distributed system, the speed of the prime movers for the generators can be adjusted to the load-dependent optimum fuel level. Hence the fuel consumption is reduced and the environmental footprint is minimized. The electrical/mechanical hybrid solution allows electricity to be generated by the main engine (Power Take Out (PTO)) or propul-sion power to be produced by generator sets and batteries (Power Take In (PTI)). A boost mode is pos-sible (additional thrust power) when the main engine and PTI motor are running in parallel.

Battery propulsionThe figure on the right shows a power supply system for a purely battery-driven vessel. The batteries are charged through an AC/DC converter (either located on the vessel or on shore). Two independent battery systems deliver power to the thruster.

Future propulsion powerIn future, it is assumed that many different types of fuel will be used. In addition, renewable energy will be required to be harvested. This situation involving several energy sources will likely require there to be a way to store the energy on board the vessels. To deal with this, an electrical distribution system with integrated batteries will be a smart solution. By preparing for a battery today, you will be prepared for the future.



POWER SUPPLY FOR BATTERIES IN SHIPPING

capacity and investment needs of 52 coastal ferry routes in Norway. The onboard investment costs and fuel costs were also assessed. The results revealed that sufficient power can be supplied at limited cost for most routes, and that for several of these ferry routes electrification may be profitable due to the reduction in fuel costs. Further case-by-case studies are needed to validate the actual profitability and must include projections of the fuel and technology costs and emis-sions pricing.

DNV GL plans to conduct further studies to evaluate current barriers as well as the demand for battery- powered ships, the emission-saving potential and the need for a shore-power infrastructure in Norway and internationally.

Authors: [email protected] and [email protected]

Sufficient and reliable power supply is a critical suc-cess factor for plug-in hybrid and all-electric ships. Ship systems require an electricity supply with a stable voltage and at certain frequencies. The shore side needs to provide the required infrastructure in order for batteries in ships to be a success. Further work is needed to standardize and develop this infrastructure.

In some cases, as for the battery-driven ferry Ampere, the local power grid’s inability to deliver sufficient power was a limitation. For the Ampere, this challenge was solved by installing battery banks at the quay to store the energy and make it available in the short time interval when the ferry is dockside. This may also be a solution in cases where load levelling is an issue, eg, when power is generated from renewables like wind and solar energy.

DNV GL has recently conducted a comprehensive study for Energy Norway1, analysing the shore power

A recent DNV GL study shows that battery ships powered from shore may now be profitable.

BATTERIES TODAY

Automatic vacuum-based mooring system ReVolt shore connection

1 DNV GL report 2015-0500. Electrification of car ferries in Norway – survey of grid investment needs. http://www.energinorge.no/getfile.php/FILER/NYHETER/ENERGI%20OG%20KLIMA/Elektrifisering%20av%20bilferger%20i%20Norge.pdf

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BATTERY HYBRID SHIPS

Like the car industry, we divide battery-powered ships into three types:

■ Full-electric ships (ES) ■ Plug-in hybrid ships (PHES) ■ Hybrid ships (HES)

On a full-electric ship, all the power, for both propul-sion and auxiliaries, comes from batteries. A plug-in hybrid ship, similar to a plug-in hybrid car (PHEV), is able to charge its batteries using shore power and has a conventional engine in addition. The ship can operate on batteries alone on specific parts of the route, when manoeuvring in port, during stand-by operations. A hybrid ship uses batteries to increase its engine performance and does not use shore power to charge its batteries.

The specific fuel oil consumption of, and emissions from, an internal combustion engine depend on the engine load. Typically, engines are calibrated for optimum performance at high loads. For ship types that experience large load variations during operation, the introduction of batteries may allow the engines to operate optimally with respect to fuel oil consumption and/or emissions. This can be achieved by selecting engine sizes that operate at optimal loads for most of the time, with additional power obtained from the batteries when required. When power requirements are low, the batteries can be charged using the excess energy generated by running the engine at the optimal load. Alternatively,

Full-electric and hybrid electric cars have seen a massive increase in popularity, motivated by rising fuel prices and environmental concerns. The introduction of hybrid technology to reduce energy consumption and emissions has not gained the same attention in the maritime industry yet, but the change has started and more and more ships are being equipped with batteries.

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BATTERIES TODAY


in operating conditions requiring very low loads, the ship may be able to operate on battery power alone.

This can also be beneficial for the engine’s mainte-nance costs since engines operating at low loads may lead to incomplete fuel combustion, potentially leading to contamination of the lubrication oil and the build-up of carbon residue on vital engine parts. Thus, the engine’s normal service intervals may be insufficient, leading to higher maintenance costs.

The engine emissions are also strongly dependent on the engine loads. The dependence varies for the various emissions. Specific emissions are normal-ly higher at low engine loads. This is particularly evident for unburned methane (CH4) emissions. CH4 is a very strong greenhouse gas (GHG) (at least 25 times more potent than CO2). Moreover, a diesel engine (using either heavy fuel oil or low sulphur die-sel) is expected to have significant particulate matter (PM) emissions, especially at low loads. An accumu-lator may therefore also be used to reduce emissions by allowing the engines to run at optimized loads with respect to emissions.

Benefits of hybrid ships: ■ Utilize energy from shore power ■ Run engines at optimum loads ■ Avoid transient engine loads ■ Use power redundancy ■ Reduce local emissions ■ Reduce noise and vibrations ■ Facilitate energy harvesting and energy recovery

Let us illustrate this with an example. Assume that a ship’s power demand varies between 500kW and 1100kW, with an average power demand of 800kW, meaning that the ship consumes 800kWh in one hour of operation. The ship has two generator sets installed, with a maximum total power output of 1000kW. Although the average demand is 800kW, the ship cannot run with only one generator set switched on since the demand sometimes exceeds 1000kW. Therefore, two generator sets must be running. The total fuel consumption of two genera-tor sets is 170 kg/hour compared with 146 kg/hour if only one generator set is switched on. If a battery was installed, the battery could take care of the vari-ations and the ship could run on only one generator set, with fuel savings of about 14%.


Showing the total power generation and fuel consumption after one hour of operation for a ship with four 1000kW generator sets (gensets). By switching off one genset, the ship can make fuel savings of approximately 14%.

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BATTERIES TOMORROWGeneral trendsWhat will happen in the battery business in the years to come? Some quotes from prominent people within the automotive business give an indication of current views1:

■ “I do think that cost per kWh at the cell level will decline below USD 200 in the not-too-distant future.” Elon Musk, CEO Tesla Motors.

■ “Today there are prototypes out there with 400 Wh/kg – the industry is in a period of rapid trans-formation.” Gary Smyth, GM Director of Global Research and Development.

■ “In the next 3-4 years there will be more progress in battery development than the previous 100 years.” Ian Robertson, BMW Board Member.

■ “Through mass production, we will soon lower production costs to a quarter of what they were in 2009.” President Makoto Yoda, GS Yuasa Corp (Mitsubishi Motors Corp battery supplier).

As clearly stated in these quotes, ongoing and potentially transformative developments are taking place in the battery sector. In the short and medi-um term, significant increases in cycle life, power and energy density and lower costs are expected. Predictions made by McKinsey & Co1, indicate that complete battery packs with automotive quality will drop in price from the current 500 USD/kWh to 200 USD/kWh in 2020 and 160 USD/kWh in 2025. The reduction in cost will partly be due to increased manufacturing volumes, cost cuts in the supply chain and improved yields.

Maritime applicationsMaritime battery systems are mostly based on the same or very similar large-format cells as those used for EVs and hybrid cars. However, the maritime battery system design is more related to the MWh systems designed for grid installations. The size, voltage and power requirements of such systems are quite similar to those for hybrid installations in ships whereas safety related requirements may differ. Maritime battery systems have benefitted strongly from the volume production of electric and hybrid cars and the rapid market penetration of grid sys-tems. The cost level for energy-optimized maritime battery systems is expected to reach the 500 USD/kWh level, where the grid systems are today, within a few years.

Battery systems can be optimized for high energy- storage capacity, as is often required for all-electric applications, or for high power applications, as in hybrids, where the purpose of the battery system is to cover peak loads and even out the generator loads. Some applications, for example electric-pow-ered ferries, will require a combination of both energy and power. The ferry will need sufficient energy to perform its trips between each charging period and the fast charging will require a battery system that is able to receive a high current from the fast charging. Energy optimized battery systems will usually be sufficient for this purpose, since the charge current relative to the battery storage capacity usually is fairly low. The cells used for the battery systems should preferably be optimized for the actual application; energy, power or a combination of these. Power applications with high currents will also require

1 McKinsey&Co (2013), “Will batteries become cheaper”, Zero Conference. 5th-6th Nov 2013.


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more efficient cooling systems. The per kWh cost of the power cells is higher than that of the energy cells and the stronger cooling also adds to the total system cost. However, the size in kWh of a power-op-timized system can be made much smaller than that of an energy-optimized system delivering the same power, resulting in a significantly lower cost per kW.

Within a few years, the gap in available energy to power ratios between supercapacitors and batteries is expected to be bridged to a larger extent for commercial applications too. The energy and power requirements for a battery system can then be met using sub systems with similar energy to power ratios or sub systems with different energy to power ratios.

Historical developmentSo far, the developments have been gradual and stepwise and each major new step has been de-pendent on the previous steps. For instance, new innovations for power-tool batteries depended on cell-construction principles and materials developed for laptops and mobile telephones. The power-tool batteries brought the first power-optimized Li-ion battery designs and introduced new cathode materi-als. With the power-optimized designs, operation in sub-zero temperatures was possible and further ma-terials development led to a longer battery lifetime than had previously been possible. These innova-tions were key enablers for the use of Li-ion battery systems in electric vehicles. The use of Li-ion batter-

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ies in electric vehicles was the key enabler for the maritime usage of such batteries since the reliability, cost, performance, lifetime and safety were brought to levels that were attractive for maritime usage. The maritime usage of large Li-ion battery systems will improve these systems in ways that will benefit other markets, such as off-grid energy systems, and lead to expanded usage for railways and commercial vehicles.

New battery chemistriesLithium is the lightest metal in the periodic table so a pure substitution of lithium by another metal ele-ment to form revolutionary new, lighter batteries is impossible. Future technologies like Li-Air, Li-Sulphur and other similar chemistries will be available for energy-optimized battery systems in a longer-term perspective and, in the even longer term, maybe also to some degree for power-optimized battery systems.

For power-optimized battery systems, the battery cell and system impedance are crucial factors and the battery-cell power to energy ratio is crucial in deter-mining the applicability in hybrid power systems.

Today, the development of high-power battery cells is driven by market segments other than the maritime. Typically, the power-tool industry and the automotive industry are the key requirement drivers.

The cathode material currently accounts for around 50% of the Li-ion cell material cost. For the maritime market, there is a possibility that cell types other than Li-ion, such as Mg-ion or Al-ion, could provide cost-competitive options since this could bring the cathode material cost down.

Authors: [email protected], [email protected] and [email protected]

Lars Ole Valøen Egil Mollestad Gerd Petra Haugom


INNOVATING FOR BATTERIES

Even though the internal resistance of lithium-ion batteries is very low and the efficiency is close to 100%, heat is generated under such tough load cy-cles. The battery life very much depends on efficient temperature management. Batteries are like human beings, their comfortable operating temperature is between 20 and 30°C.

To be able to keep the temperature within this inter-val during heavy and long-lasting load cycles, active cooling of the battery system is needed. Such cooling can be either air- or liquid-based. There have been huge improvements in battery life over the past few years. Well-designed systems based on high quality and long-lasting cells can even for heavy applications be designed to last for many years. A ten-year system

life has been the target for many of the recent battery projects. However, given the rapid development in battery technology and significant reduction in battery prices that are expected over the next few years, it might be a worthwhile task to investigate if a shorter design life will give a better business proposition.


Maritime batteries systems are often subject to tough load profiles. Both peak shaving in hybrid applications and fast charging in all electric applications put considerable stress on the batteries.

SAFER AND SUSTAINABLE SHIPPING

BATTERIES TOMORROW


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THE REVOLT – A NEW, INNOVATIVE SHIP CONCEPT

No crewNamed the ReVolt1, this vessel is 60 metres long, fully battery-powered and autonomous – it requires no crew.

This is a new shipping concept for the short-sea segment that offers a possible solution to the growing need for transport capacity.

The EU road network is suffering from congestion and the population growth in urban areas will lead to a demand for transportation that exceeds the capacity of existing roads. To alleviate these issues, govern-ments all over the EU are trying to move some of the freight volume from roads to waterways. However, profit margins in the short-sea shipping segment are small.

Annual savings > USD 1.6MThe ReVolt is an innovative ship concept that is the result of a multi-disciplinary, team-based develop-ment project at DNV GL supported by Transnova, Norway and is based on an assessment of current requirements along short-sea routes. The vessel will operate at a speed of 6 knots, with a range of 100 nautical miles and a cargo capacity of 100 twenty-foot containers.

The battery-powered propulsion system is an energy-efficient solution. Together with hydro pow-

Taking current technology to the extreme, DNV GL has developed a new and revolutionary concept for an unmanned, zero-emission shortsea vessel.

1 Tvete H.A. “ReVolt” for Transnova AS, DNV GL Report 2015-0170 [Report], 2015

FACTS AND FIGURES

Main particularsLOA 60.23 mLPP 57.23 mBeam 14.5 m

Depth 12.18 mDraught (full) 4.84 mDraught (ballast) 3.09 mService speed 6 kn

CapacityCargo capacity 100 TEUDeadweight 1,250 mtCruising range 100 nm Machinery

Battery 5,422 kWh

PropulsionAzimuth pods with 2 blades (3 m diameter) 2Retractable bow thruster 1

BATTERIES TOMORROW


ReVolt electrical connection

er, it significantly contributes to the ReVolt’s high well-to-propeller efficiency of 63%.

Batteries also alleviate the need for continuous maintenance, a big concern for unmanned ships. The ReVolt’s autonomous capabilities significantly reduce or even eliminate the need for crew facilities, a superstructure and auxiliary machinery, leaving more space for payload. The battery pack is, howev-er, quite capital intensive, with an estimated cost of 1,000 USD/kWh. Due to the performance degrada-tion of batteries after long-term usage, the battery pack will need to be replaced over the vessel’s

estimated 30-year lifespan. With a battery size of around 5.5MWh, the ReVolt’s CAPEX is estimated to be 9.5MUSD, 1.4MUSD more than that of a conven-tional ship. But where the ReVolt will truly excel is in terms of reduced operating costs. The energy, main-tenance and crewing costs will be far below those of a diesel-powered ship. The savings will depend on the shore-side infrastructure needed to enable the autonomous operations. The ReVolt’s yearly OPEX is estimated to be close to 517,000USD, which is 4.5 times less than that of a comparable conventional diesel-powered ship, leaving the return of investment less than one year. Over its lifetime, the ReVolt can

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save about 48MUSD in operating costs compared to a conventional vessel. Future governmental emission-reduction incentives might further increase this margin.

A vision – within our graspThe ReVolt is a vision for the future and will not be built until several of the technologies involved have matured. However, it could conceivably be built and operated using current technology. It is intended to serve as an inspiration for equipment manufacturers, shipyards and shipowners as they endeavour to de-velop new solutions for a safer and more sustainable future.

The ReVolt was initiated as a research project in August 2013 and launched externally a year later.

The ReVolt model demonstratorWork on this will continue – and be extended to involve land-based charging facilities and capacities – as a research project within DNV GL. For the purpose of testing the ReVolt’s autonomous capabilities, a 1:20 scaled model has been built. Through collab-oration with the Norwegian University of Science and Technology (NTNU), this model will serve as a test bench in researching sensor fusion and collision avoidance for autonomous surface vehicles. This competence project will run for three years starting in third quarter 2015.


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WITH BATTERIES TOWARDS THE TWO-DEGREE TARGET

The Norwegian government has stated its aim to contribute to a transition to the use of green fuels in the maritime sector. On behalf of the Ministry of Climate and Environment, DNV GL Maritime Advisory has analysed the emission-reduction potentials and cost-benefits of alternative fuels towards 2040, covering biofuels, battery electrification and LNG.

The analysis builds on a detailed description of mar-itime traffic, fuel usage and emissions from shipping in Norwegian waters, and allows regulators– for the first time ever – to separate activities and emissions relating to domestic, international and transit ship-ping. This was made possible by DNV GL’s unique ability to process and analyse satellite-based AIS – Automatic Identification System – data.

Batteries could propel Norway’s domestic shipping towards the two-degree target. A recent study by DNV GL demonstrates how maritime batteries are a key technology in order for Norwegian domestic shipping to contribute to national CO2-reduction targets.

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The world’s first ship to run purely on battery power now operating on the Norwegian fjord Sognefjorden.


2015 2040

The challenge is to cut emissions to 40% below current level

Without measures, CO2 emissions could grow by 60% between 2015 and 2040

CO2

CO2 emissions from Norway’s domestic shipping may increase significantly towards 2040, while large emission cuts are needed to reach the two-degree target. Achieving the necessary emission reductions using green fuels requires the use of zero-emission options such as electricity and biofuels.

Magnus Standmyr Eide

The study shows that reducing CO2 emissions in 2040 to below 2015 levels using green fuels will require the use of zero-emission options such as electricity and biofuels. The cost-effectiveness of all the measures will vary according to the fuel-price scenario, but both battery electrification and biofuels will give cost-effective CO2 reductions across a range of scenarios. Hybrid solutions will also contribute to emission reductions, and battery hybridisation is found to be highly cost-effective.

This study forms a basis for Green Coastal Shipping Programme and further work on policy instruments to encourage the transition to green fuels, including maritime batteries. As other nations have CO2-reduction commit-ments and challenges that are similar to Norway’s, DNV GL sees an interna-tional market for this type of analysis.



GREEN COASTAL SHIPPING:

NORWAY – A SHOW-CASE FOR GREEN SHIPPING

We in the Green Coastal Shipping Programme (GCSP) have a vision that Norway will establish the world’s most effective and environmentally friendly coastal shipping, powered wholly or partially by batteries, LNG, or other eco-friendly fuels. This vision encompasses the entire coastal fleet, including offshore vessels, tankers, general cargo, container, bulk-carrier and passenger ships, ferries, fishing and aquaculture vessels, tugs and other coastal vessels. “Norwegian coastal shipping can become a show-case in the world, a platform for Norwegian exports of green technology and environmentally friendly transport services. The technologies are there. Now we need to develop an effective infrastructure and scale the deployment,” says Remi Eriksen, DNV GL Group EVP and COO.

In mid-January, DNV GL arranged a roundtable con-ference at which the Norwegian Minister of Climate and Environment and Minister of Trade and Industry and 17 top executives from the industry signed a declaration of collaboration. This marked the start of the Green Coastal Shipping Programme.

Norway is going to show the world that tomorrow’s shipping industry will be eco-friendly. The Green Coastal Shipping Programme, initiated and headed by DNV GL, has high ambitions starting with short-sea shipping. They want to show the way towards a future zero-emission industry.

Establish the world’s most effective and environmentally friendly coastal shipping

This will require a common commitment across industry and state agencies to help:

■ Reach global and national climate goals ■ Reduce emissions to air which are dangerous to human health and the environment

■ Create green jobs and innovative, competitive technologies and services

■ Create significant export opportunities for the Norwegian maritime, energy and supplier sectors

■ Implement the government’s and parliament’s environmental ambitions and create profitable, lasting emissions reductions

■ Make Norway a world leader within green shipping and attract international attention

VISION:


A joint effortThe programme will be realized by the industry and government working together in a long-term public- private partnership. This is a joint effort in which all the significant players in the value chain contribute, ie, cargo owners, logistic companies, ship owners, ports, and vendors of electricity, gas, equipment and services. “This is important,” explains Narve Mjøs, the programme director. “For example, ship owners will not install LNG or battery technology for all-electric operation before the infrastructure is in place. But gas and electricity suppliers and ports will not build the infrastructure before the market is there. And thirdly, it does not help that the ships can sail and fill green fuel from a well-developed infrastructure if cargo owners and logistics companies will not prior-itize sustainable transportation. The authorities must facilitate it all to happen. The programme can be an effective instrument for the implementation of the government’s new port and maritime strategies.”

The Ministry of Climate and Environment (KLD) participates in GCSP as an active contributor to a green shift in the shipping industry and to listen to

industry’s needs, according to State Secretary Lars Andreas Lunde in KLD.

Norway Post, a Nordic mail and logistics group, is a major player and has a large fleet of trucks. Its Director of Environment and Social Responsibility, Colin Campbell, believes the group’s knowledge as both a carrier and buyer of transport services is valuable in GCSP. “We’re working to get more transport by sea. Some types of cargo are better suited than others, but certain assumptions must be in place. There we have a lot to contribute,” says Campbell.

The programmeGCSP will be long term, probably lasting for more than 30 years, but there will be short-term results and demonstration projects/pilots in all phases. The main activities are as follows:

Phase 1 – Study of the potential ■ Assess the potential for battery- and gas-based transport in Norway

■ Business economic analyses

Monica Mæland, the Norwegian Minister of Trade and Industry, and State Secretary Lars Andreas Lunde, representing Tine Sundtoft, the Minister of Climate and Environment, DNV GL’s Remi Eriksen and 16 other top executives from the industry signed a declaration of collaboration. This event marked the initiation of the Green Coastal Shipping Programme.

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■ Socio-economic analyses ■ Cost/benefit assessments of a green shift

Phase 2 – Business cases ■ Further develop and evaluate the business case for all main players in the value chain

■ Define regulatory, financial and procurement policy incentives and instruments

■ Establish consensus on how key barriers and challenges can be overcome

Phase 3 – Implementation planning ■ Define realistic goals for reduced emissions of CO2, SOx, NOx, PM and for socio-economic results such as increased green employment, value creation, productivity and exports

■ Develop an implementation plan

Phase 4 – Implementation ■ Implement and validate GCSP

Piloting in Phase 1The objective of initial piloting, Phase 1a, is to conduct a feasibility study for selected pilots to clarify the environmental and cost implications of various innovations.

■ Focus is on LNG and battery operation ■ The overall concept, investments, changing oper-ational costs and payback will be considered at a high level for each demonstration project

■ It is an overarching objective to start implementing five demonstration projects in the tail of the Phase 1a

■ Phase 1a has a duration of one year

GREEN COASTAL SHIPPING PROGRAM IS ABOUT

z Profitable emissions reductions

z Green jobs

z Increased competitive advantage

z Leading position internationally


■ The documentation from the pilot projects will be used by the pilot owners to prepare more detailed project descriptions and financing plans for the actual implementation of the pilots, including ap-plications for funding from Innovation Norway, the NOx Fund and other relevant bodies

“Phase 1a is jointly funded by 20 industry partners and the governmental body Innovation Norway,” says Narve Mjøs. So far, two pilots have been selected for Phase 1. The first is NorLines’ future cargo ferry with LNG/battery hybrid propulsion, zero-emission port sailing and port operation, including electric cranes with energy recovery. CEO of NorLines Tor Arne Borge is very positive and enthusiastic, but he cannot refrain from stating that the government can do more to speed up the cargo shift from road to sea and green coasting. “It’s amaz-ing what the government has achieved by facilitating more electric cars. Now we need to get the authori-ties to create similar incentives for coastal transport,” says Borge.

The second pilot involves Teekay’s next-generation green shuttle tanker and the goals are to investigate and determine the feasibility of using alternative fuels such as LNG and/or VOC in combination with robust power generation for offshore DP operations and to evaluate the potential use of batteries in a hybrid solution.

Three more pilots will be selected in June 2015.

Why join GCSP? ■ Influence future regulatory, financial and procurement policy instruments and incentives

■ Evaluate and influence changes in market conditions

■ Identify new business opportunities ■ Obtain revenue growth, cost savings and competitive advantages

■ Take a leading position within green shipping


■ Norwegian Shipowners’ Association ■ Cargo Freighters’ Association ■ Nor Lines ■ ABB ■ Energy Norway ■ The Confederation of Norwegian Enterprise ■ GasNor ■ Statoil ■ Federation of Norwegian Industries ■ DNV GL ■ Teekay Shipping Norway ■ Norwegian Gas Association ■ The NOx Fund ■ Norway Post ■ Norled ■ Kongsberg Maritime ■ KS Bedrift ■ Risavika Havn ■ Norwegian Electric Systems ■ ZEM ■ Ministry of Climate and Environment ■ Ministry of Trade, Industry and Fisheries ■ Innovation Norway ■ National Transport Plan ■ Norwegian Coastal Administration ■ Norwegian Maritime Authority ■ Maritime Battery Forum

More Norwegian and foreign participants are welcome

GREEN COASTAL PROGRAM PARTICIPANTS:

Advantages(climate, environment, transport and industry)

10 years 20 years

Market driven development

Awareness, start-incentives, and pilot studies

New green frameworks

Level of ambition Green shipping program


ALTERNATIVE FUELS FOR SHIPPING

The main drivers leading to the advent of alternative fuels in the future can be classified in two broad categories:

■ Regulatory requirements and environmental concerns, and

■ Availability of fossil fuels, cost and energy security.

The upcoming requirements for reduced sulphur content in the fuel will increase the cost of the fuel. This effect will be more pronounced after 2020 (or 2025, depending on when the new regulations are enforced), when the sulphur content globally will be at 0.5% (or 5,000 ppm), which is lower than current levels for the ECAs. Introducing exhaust gas aftertreatment systems, such as SOx scrubbers and urea-based catalysts for NOx reduction, can add significantly to the cost of a ship. These systems are both space-demanding and costly, while they can increase the fuel consumption by 2–3%. On the other hand, they allow for the use of less expensive, high sulphur fuels. Introducing new, sulphur-free fuels can be a viable solution for this problem, provided that

these fuels and the necessary technology are offered at competitive price levels.

The fuel consumption in the ECAs is estimated at approximately 30–50 million tons of fuel per year and it is going to increase if more areas are included in the ECAs in the future. These figures are important for evaluating the potential of each one of the alternative fuels presented in this report for replacing oil-based fuels.

Overview of potential alternatives Over the next four decades, it is likely that the energy mix will be characterised by a high degree of diver-sification. LNG has the potential to become the fuel of choice for all shipping segments, provided the infrastructure is in place, while liquid biofuels could gradually also replace oil-based fuels. Electricity from the grid will most likely be used more and more to charge batteries for ship operations in ports, but also for propulsion of relatively small vessels. Renewable electricity could also be used to produce hydrogen,

The merchant world fleet gradually shifted from sail to a full engine powered fleet from about 1870 to 1940. Steamships burning coal dominated up to 1920, and since then coal has gradually been replaced by marine oils, due to the shift to diesel engines and oilfired steam boilers. The shift from wind to coal was driven by the developments in steam engines, and offered the opportunity for more reliable transit times, to a large extent independent of the weather conditions and prevail-ing wind directions. The following shift, from coal to oil, was driven by increased efficiency, ease of handling, and cleaner operations.


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which in turn can be used to power fuel cells, provid-ing auxiliary or propulsion power. If a drastic reduc-tion of GHG emissions is required and appropriate alternative fuels are not readily available, carbon capture systems could provide a radical solution for substantial reduction of CO2. While renewable energy, eg. solar and wind may have some potential to mitigate carbon emissions, this is not seen as a viable alternative for commercial shipping. Certain-ly, vessels equipped with sails, wind kites or solar panels may be able to supplement existing power generating systems, but the relative unreliability of these energy sources make them appropriate only for special cases where favourable weather condi-tions prevail.

Ship electrification and renewables Recent developments in ship electrification hold significant promise for more efficient use of energy. Renewable power production can be exploited to produce electricity in order to power ships at berth, cold ironing and to charge batteries for fully electric and hybrid ships. Enhancing the role of electricity on ships will contribute towards improved energy management and fuel efficiency on larger vessels. For example, shifting from AC to on board DC grids

would allow engines to operate at variable speeds, helping to reduce energy losses. Additional benefits include power redundancy and noise and vibration reduction, which is particularly significant for passen-ger ferries. Energy storage devices are critical for the use of electricity for ship propulsion, while they are also important for optimization of the use of energy on board in hybrid ships. There are several energy storage technologies currently available. Battery powered propulsion systems are the most popular ones, and they are already being engineered for smaller ships. For larger vessels, engine manufactur-ers are focussing on hybrid battery solutions. Chal-lenges related to safety, availability of materials used and lifetime must be addressed to ensure that battery- driven vessels are competitive with conventional ones, but the pace of technology is advancing rapidly. Other energy storage technologies that could find application in shipping in the future include flywheels, supercapacitors, and thermal energy storage devices.

Electrification has generated strong interest, par-ticularly for ship types with frequent load variations. Significant growth in hybrid ships, such as harbour tugs, offshore service vessels, and passenger ferries should be expected in the next few years.


The way forward The introduction of any alternative energy source will take place at a very slow pace initially as technologies mature and the necessary infrastructure becomes available. In addition, introduction of any new fuel will most likely take place irst in regions where the fuel supply will be secure in the long-term. Due to uncertainty related to the development of appropri-ate infrastructure, the new energy carriers will first be utilised in smaller short sea vessels, and small ferries are expected to be some of the first movers. As technologies mature and the infrastructure starts to develop, each new fuel can be used in larger vessels.

The adoption of LNG will be driven by fuel price developments, technology, regulation, increased availability of gas and the development of the appro-priate infrastructure. The introduction of batteries in ships for assisting propulsion and auxiliary power de-mands is also a promising low carbon energy source. Ship types involved in frequent transient operations (such as frequent manoeuvring, dynamic position-ing, etc.) can benefit most from the introduction of batteries through a hybrid configuration. Moreover, energy storage devices can be used in combination with waste heat recovery systems to optimise the use

of energy on board. Cold ironing could become a standard procedure in many ports around the world.

It is very likely that in the future there will be a more diverse fuel mix where LNG, biofuels, renewable electricity and maybe hydrogen all play important roles. Electrification and energy storage enable a broader range of energy sources to be used. Renewable energy such as wind and solar can be produced and stored for use on ships either in batteries or as hydrogen. Besides IMO rules and ISO standards, development of appropriate Rules and Recommended Practices is necessary for the safe implementation of any of these technologies in the future. To achieve this, the role of Class Societies will be crucial. Adopting new technologies is likely to be an uncomfortable position for shipowners. To ensure confidence that technologies will work as intended, Technology Qualification from neutral third parties, such as classification societies, is also likely to be more widely used.


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■ Increased confidence for owner, charterer, investor and other stakeholders

■ After retrofit, all benefits that are listed below under Option 2

Option 2: Vessel ready for battery operation today, new building or retrofitBuild or retrofit a vessel with battery system and engines/motors installed and ready to run on battery from first day of operation.

Benefits ■ Cost-benefit assessment illustrates the vessel’s performance to ship owners and charterers

■ Cost reductions from optimization of engine/ motor size versus battery size

■ Independent and credible battery service life assessment

■ Avoid engine loads where Tier III-solutions, such as LNG and SCR, have non optimum emission performance

■ Optional storage of energy from waste heat recovery, regenerative braking and renewables

■ Enlarged negotiation power towards battery vendors.

DNV GL’s Maritime Advisory provides decision support to ship owners, designers and yards for making vessels ready for future battery retrofit or ready for battery operation today – pure battery or battery hybrid with diesel or LNG. Based on technical and financial feasibility studies, DNV GL helps you select the best option according to operational and environmental requirements. The DNV GL Guideline for Large Maritime Battery Systems is a reference document for this work. There are two options for making a vessel Battery Ready:

Option 1: Vessel ready for future battery retrofitBuild a vessel that will use a diesel or gas based power system that can easily be retrofitted with batteries in the future. This can be a good option for ships under construction or existing conventional designs.

Benefits ■ DNV GL validates that the system is optimized for easy retrofit

■ Minimum investment requirement ■ Cost-benefit assessment pinpoints when a full conversion is attractive

Electric and hybrid vessels with energy storage in batteries and optimized power control can provide significant reductions in fuel consumption, maintenance and emissions. Such solutions also enable improved ship responsiveness and thereby im-proved operational regularity and performance, as well as safety in critical situations.

BATTERIES – THE RIGHT OPTION?

BATTERY READY SERVICE


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1. Strategy – Power and energy system decision ■ Technical feasibility assessment: ■ Battery system location, sizing and range in battery mode based on the ship operational requirements/ profile

■ Estimation of operational life of the battery system ■ Engine/motor system location and sizing based on the ship operational profile

■ Outline of key requirements for a Battery Ready design

■ For future retrofit: High level list of technical changes that will be required

Financial analysis: ■ A high-level financial comparison of engine/motor options and battery options including both invest-ment cost and oper ational expenses

■ Sensitivity analysis for impact of fuel price develop-ment (and of battery price if future retrofit)

The path to become “Battery Ready”DNV GL’s Maritime Advisory can assist you all the way from planning, concept design, and approval in principle, to a final business risk and safety risk analysis as required by DNV GL Class requirements. This can be done in four phases as described below.

Strategy – Power and energy system decision ■ High level technical feasibility ■ Cost, payback time and sensitivity analysis

Concept capture ■ Detailed technical feasibility study ■ Concept design review / HAZID

Initial design ■ Approval in Principle

Risk management ■ Battery system safety risk analysis (mandatory if DNV GL Battery Power Class)

■ Battery system business risk assessment

THE PATH TO BECOME “BATTERY READY”


■ High level evaluation of strengths and weaknesses (e.g. SWOT analyses) of alternative solutions with respect to technical issues, environmental aspects and economy

2. Concept capture ■ Development of novel ship designs and detailed technical feasibility studies tailored to the specific design and technical challenges of your vessel

■ Advanced power system analysis (COSSMOS) ■ Hazard identification (HAZID) review of the concept to identify hazards which could lead to high risks in operation.

■ Assistance with design reviews of existing drawings at an early stage

3. Initial design ■ DNV GL offers verification of the design concept and confirmation of compliance through DNV GL’s Approval in Principle. Ships preparing for battery retrofit are ready to start the process as soon as the investment climate is right

■ DNV GL helps you to identify and mitigate the risks associated with a given design to ensure the development of a safe and cost effective system right from the beginning

4. Risk management ■ DNV GL will perform a risk analysis to identify, rate and manage safety risks and business risks

■ The DNV GL battery guideline state that a risk analysis shall be undertaken for any new or altered concept with the goal to document a safety level which is at least equivalent to a new, comparable diesel-fuelled vessel

■ DNV GL has the tools and competence needed to help in the qualification of battery related systems

Author: [email protected] costs and operational costs in a life cycle perspective. The analysis illustrates payback time and the value of the investment over the lifetime of the ship for relevant options.

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Break-evenpoint

Cumulative total cost compared to baseline

Baseline

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ENVIRONMENTAL AND SOCIAL ASPECTS

For hybrid applications, the answer is given by the energy and emission savings in the usage phase compared to the energy used in, and emissions from, producing and recycling the batteries.

Maritime battery systems are often designed for many hours of operations every day and a 10-year service life. Compared to an EV, the usage phase counts for many more hours in a ship installation. The energy used in, and emissions from, producing and recycling the battery are only small fractions of the energy and emissions saved by the reduced fuel consumption of the diesel or LNG engines.

Battery-powered ships that are charged from the grid and the environmental savings depend on the emis-sions created by generating the electricity. For the Norwegian electricity-generation mix, with close to 100% renewable electricity generation, the savings from all electric ferries are huge. Here too, the ener-gy and emissions related to producing the batteries are small amounts compared to the savings due to the many hours of operation. Again, compared to electric vehicles, the electrification of ships gives a much better life-cycle result.

In contrast to lead-acid batteries which contain poi-sonous lead, nickel cadmium batteries that contain even more poisonous cadmium and NiMh batteries

Questions are often raised about how environmentally friendly battery-powered solutions are in a life-cycle perspective.

Illustration of the distribution of CO2 emissions for a hybrid ship. The energy used in, and emissions from, producing the batteries are only small fractions of the energy and emissions saved. Source: DNV GL


that contain rare earth materials, the lithium-ion batteries contain no poisonous heavy materials and very little rare earth materials. Their main environ-mental footprint comes from the energy used in the production process, but as explained above the environmental benefits of maritime battery systems by far exceed the negative impact from the battery production itself.

Recycling All batteries independent of chemistry shall be recycled and in most countries importers of batteries have to sign up to a battery recycling scheme. Facilities for recycling of lithium-ion batteries are excisting and the value of the recycled materials more or less pays for the cost of the recycling.

Author: [email protected] and [email protected]

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STATIONARY ELECTRICITY STORAGE

There is at least 140GW of bulk energy storage currently installed in electricity grids worldwide. The largest volumes are delivered by pumped hydropower, compressed air and battery technologies. Many innovative technologies are at various stages of maturity – some are already deployed or in different demonstration stages.

Energy storage offers tremendous potential and opportunity for producers, transporters, distributers and end users of electric energy around the world. Key factors affecting the variable geographical de-velopment of stationary electricity storage are:

■ Solar energy will be a primary driver of the large-scale deployment of stationary energy storage, with PV installations growing at a rate of 15–25% per year.

■ The drivers for, and barriers to, the deployment of energy storage are almost unique to each country and market area.

■ Regulatory policies have a direct impact on the storage market but are complex and vary across states/countries.

Electricity storage in Li-ion batteries has already become established in markets such as automotive and maritime. The advancement of stationary energy storage and the related markets is expected to expand the utilization of multiple energy-storage

From the early days of the grid, organisations have sought ways to safely store energy in order to improve grid-power quality and reliability and optimise the matching of supply and demand. The increased penetration of renewable energy technologies and the stress they impose on the grid have contributed to the greater focus on electricity storage.

FACT BOX 1

DNV GL – Energy’s 2,500 energy experts support customers around the globe in delivering a safe, reliable, efficient, and sustainable energy supply. Our testing, certification and advisory services are delivered independent from each other.

With our dedicated electricity storage labs in Europe and the U.S., DNV GL – Energy has a long history of testing and demonstrating storage technologies for utilities.


technologies. Examples are pumped storage and compressed air energy storage, power devices (flywheels), energy devices (sodium-based and flow batteries) and hydrogen. Stationary energy-storage applications are also expected to generate alterna-tives to Li-ion technologies. The chart below shows a variety of requirements in the stationary market and that Li-ion batteries are not always the best choice for different stationary applications. No single technolo-gy is able to serve all the high-energy and high-pow-er needs. High-energy applications require storage

devices to discharge their energy at rated power for longer than one hour and high-power applications often need storage to discharge all their energy within an hour, or often a much shorter time. In addi-tion, storage technologies in the stationary-applica-tions sector will be required to perform multiple or bundled applications, such as a combination of load levelling, frequency regulation and backup power.


The relative feasibility of different energy-storage technologies for a variety of stationary and non-stationary applications. Green: High feasibility. Yellow: Medium feasibility. Red: Low feasibility. Source: Ali Nourai/DNV GL Energy

Energy storage technologies Feasibility for stationary applications Feasibility for non-stationary Applications

Energy storage technologies and abbreviations

Applications that call upon storage very

frequently

Applications that call upon storage

occationally Maritime propul-

sion

Oil and gas

Transpor-tationHigh-

energy application

High- power

application

High- energy

application

High- power

application

Valve regulated lead acid VRLA

Thermal storage (Hot) Heat

Pumped Hydro P-Hydro

Litium – ion – High power LIB-p

Ni batt. (NiCd, NiZn, NiHM) Ni-batt

Thermal storage (cold) Ice

Compressed-Air ES, cavern CAES-c

Sodium Sulfur NaS

Flywheel FlyWi

Litium – ion – High energy LIB-e

Advanced Lead Acid LA-adv

Hybrid LA and IDL-CAP Hybrid

Vanadium Redox Battery VRFB

Zink Bromide ZnBr

Sodium Nickel Chloride NaNiCl

Double Layer (super) Capacitors DL-CAP

Adv. Vanadium Red. Flow. Batt. A-VRFB

Zinc-Air Battery ZnAir

Compressed-Air ES, small CAES-s


OPERATION OF A HYBRID CRANE

To illustrate the benefits of hybrid power, its use for crane operations has been simulated on a Grieg Star 50,000dwt open-hatch vessel. The ship has four slew-ing-type cargo cranes and three auxiliary generator sets with nominal electrical power output of 960kW each.

The average hotel load (the electrical power used by the crew areas, bridge, etc) was stated by the owner, Grieg Star. In addition, Grieg Star provided the cranes’ estimated loading cycle and detailed information about the crane load, including the

DNV GL has performed a simulation study of a Grieg Star 50,000dwt open-hatch vessel with four cranes. The study reveals a fuel-consumption reduction of more than 30% during crane operations – now to become a reality.

CRANE LOADING CYCLE

Load on 60 s 20 kW

Hoisting of load 15m 45 s 372 kW

Luffing in + hoisting 5m 14 s 475 kW

Slewing 75 deg 27 s 80 kW

Lowering 10m 27 s -212 kW

Load off 10 s 20 kW

Hoisting empty grab 5m + Slewing 75 deg 15 s 125 kW

Luffing out + Lowering empty hook 15 m 30 s -89 kW

EXPERIENCES – HYBRIDIZATION WITH BATTERIES


duration of each part of the loading cycle and the electric power used by the cranes. As the cranes are fully electric, the electric motors can use regen-erative braking, where electricity is generated by lowering the crane. The power used by the cranes is taken from the ship’s alternating current grid, and in conventional ships the energy generated by regen-erative braking goes to waste. In a hybrid ship, how-ever, the power created by the regenerative braking is sent to the grid and battery.

Models of lithium-ion batteries, diesel generator sets, cranes and the ship’s hotel load were created and combined to simulate the crane operations. Using real data supplied by the ship owner to calibrate the models, DNV GL is in a unique position to accurately quantify the benefits of a hybrid installation.

The results of the simulation indicate that the ship could reduce its fuel consumption by as much as 30% and achieve yearly savings of USD110,000, with less than a one-year payback time for the battery installation. In addition, battery installations on ships using hybrid power significantly reduce emissions and fuel consumption.

Based on these analyses, Grieg Star will this year install a power optimized battery system from Gren-land Energy in order to achieve substantial environ-mental benefits and reap the cost efficiency benefits. The battery system will be fully integrated with the power management system from Kongsberg Mari-time.

Autor: [email protected]

HOW TO OBTAIN OPTIMAL LOAD, REDUCED TRANSIENTS AND REGENERATIVE BRAKING

Battery discharges when power demand is greater than the Diesel engine output:

Battery charges when power demand is less than the Diesel engine output:

We now have: ■ Optimal load ■ Reduced transients ■ Regenerative braking

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VIKING LADY – REAL-LIFE SHIP PERFORMANCE

Recent developments in ship electrification have made ship machinery hybridization and smart power management possible, leading to more efficient use of energy on board. High-power and high-energy density batteries are suitable for full or hybrid elec-tric propulsion, paving the way for near-zero emis-sion shipping. Battery technologies like Lithium-Ion (Li-ion) exhibit efficiencies of up to 98% at a currently estimated cost of about 600 USD/kWh.

The Viking Lady is the first merchant ship to be pow-ered by a battery-hybrid propulsion plant. She is a 92-metre-long DNV GL-classed offshore supply ves-sel owned by Eidesvik Offshore ASA and operates daily in the North Sea, Figure 1. Built in 2009 with dual-fuel engines and conventional diesel-electric propulsion, her energy system was gradually hybrid-ized with full-scale energy conversion and storage technologies within the FellowSHIP series of research and development projects.

The first phase of the FellowSHIP project (2003) was dedicated to investigating the feasibility of onboard Fuel Cell (FC) technologies, and resulted in the development of the first classification rules for maritime FCs. During the second phase, a 320kW

Molten Carbonate Fuel Cell (MCFC) was fitted on board the Viking Lady for supply of auxiliary power. In the third FellowSHIP phase, a 450kWh capacity Li-ion battery was added to the power train, convert-ing the vessel to a battery hybrid-electric propulsion one. FellowSHIP III was coordinated by DNV GL, with shipping company Eidesvik Offshore ASA and manu-facturer Wärtsilä as project partners. The project was co-funded by the Research Council of Norway.

DNV GL’s in-house modelling and simulation plat-form COSSMOS (COmplex Ship Systems MOdelling and Simulation) played a key role in the project. It was instrumental in performing early-stage feasi-bility and performance analyses of the integrated hybrid system. Advanced COSSMOS simulations identify the optimal power management strategies to maximise the energy gains while ensuring the vessel’s safety and operational capabilities. Figure 2 shows the COSSMOS model of the Viking Lady’s hybrid-propulsion plant. As the gen-sets provide the lower base loads, the integrated system consumes less energy and has increased redundancy, making operations safer and more efficient. Other benefits are lower levels of noise and vibration.

The Viking Lady is an offshore supply vessel (OSV) in daily operation in the North Sea and a full-scale real-life “test laboratory”: LNG-fuelled with battery-hybrid propulsion. The onward focus is on extensive monitoring of real-life operational conditions and performance to optimise operations and prove reliability and safety.


The battery-hybrid installation was tested in sea trials in 2014. The fuel cell stack was not operated. Figures 3 and 4 summarize the sea trial results for DP in good and bad weather, respectively. The hybrid operation is compared to the conventional one (only gen-sets). In both figures, the green columns (hybrid) show the benefit of switching off one gen-

set while operating on batteries. In hybrid operation, significant fuel savings and emissions reductions are achieved by the combination of appropriate battery sizing and optimal power-management strategies. An annualised projection of the results for all of the vessel’s operational modes (transit, DP, standby, harbour) show that a 15% reduction in fuel

Figure 1. The Viking Lady OSV: the first full-scale hybrid-electric vessel.


consumption, 25% reduction in NOx emissions and 30% reduction in GHG emissions can be realised in practice, with marked improvements in DP opera-tions in particular.

DNV GL has developed classification rules to ensure the safe installation and operation of large battery power packs on ships. The rules have been official since 2012, covering all of the significant aspects of using battery packs in a maritime context, from de-sign through to installation and verification. A new revision of the rules will be published in 2015.

Driven by such research and development, the num-ber of ship-electrification projects for small and large vessels are increasing, while a variety of DNV GL decision-support tools and services are becoming available, including the DNV GL Rules for Battery Power, the DNV GL Guideline for Large Maritime Battery Systems and the Battery Ready Service1.

DNV GL invests 5% of its revenue in research and innovation every year; investments leading to tech-nology development and better services. DNV GL has invested over USD 2.5 million in the FellowSHIP series of projects to improve the safety and sustaina-bility of our industry in practice.

Figure 2. COSSMOS model of the battery-hybrid propulsion system on board the Viking Lady. The battery acts as an energy buffer covering the intense demands that occur especially during DP and standby operations.

1 https://www.dnvgl.com/maritime/advisory/battery-hybrid-ship-service.html


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Figure 3. Sea trials: hybrid system performance in DP mode during calm weather.

Ongoing activitiesDuring the next two years, DNV GL will continue this work in the fourth phase of FellowSHIP. The main focus will be on the extensive monitoring of real-life operational conditions and performance – in particular those of the battery pack, in order to prove reliability, safety and operational benefits. The Viking Lady’s existing sensor network will be extended and ship motions due to wind, waves and currents will be measured. The focus will also be on improving further operations and the control strategy for the hybrid-energy and propulsion systems. The ad-vanced control system that makes use of our advanced COSSMOS model-based methods for the

power system combined with hydrodynamic model predictions are key enablers for such an efficient power-production system. Demonstrating this kind of control will be a breakthrough in efficient vessel operations.


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Figure 4. Sea trials: Hybrid system performance in DP mode during bad weather.


BATTERY FERRIES, A CRAZY IDEA?

A new green business caseThe battery hybridisation of ferries can provide fuel-cost savings of 10% to 30%, with a payback time of three to five years, while all-electric ferries can produce fuel-cost savings of 30% to 80% depending on the oil price. The payback time for all-electric ferries is, of course, largely dependent on the way in which electricity prices develop and the onshore investments necessary to provide sufficient power to the vessel.

The first large all-electric ferry in operationIn Sognefjorden, Norway’s deepest fjord, ferries run back and forth between Lavik and Oppedal. The crossing takes just twenty minutes, but is a vital link on the E39 route from Kristiansand to Trondheim. The connection is served by three ferries and now – for the first time ever – one of them is not using fossil fuels for propulsion. Norled’s Ampere, built by Fjellstrand, makes use of its ten tonnes of lithium-ion batteries and nothing else to ferry up to 120 cars and 360 passengers across Sognefjorden.

Ampere is an 80.8-metre-long catamaran propelled by two azimuth Rolls-Royce thrusters driven by two 450kW Siemens motors, one set at each end. During normal operation, only the aft thruster will be in

use. As from January 2015, it starts the working day with fully charged batteries and uses the frequent ten-minute stops on either side of the fjord for partial recharging. The batteries are fully recharged during the night. This regime is made possible by introduc-ing a bit of smart-net technology, boosting the local grid with batteries in each port for quicker recharging.

Ampere has the DNV GL class notation “@1A1 LC R4(nor) CAR FERRY C BATTERY POWER”. The most interesting part of this array of annotations is “Battery Power”. The battery power notation is mandatory for vessels that use batteries as one of their main sources – or the sole source – of energy for propulsion.

The battery power class notation is just one of many examples of how DNV GL promotes a safer, smarter and greener future. Innovation and environmentally friendly technologies are necessary, but insufficient when it comes to making an impact in the real world. When green measures can be designed in a way that makes them economically and/or politically attractive – then real and positive change is possible and even probable.


Ferries with Li-ion batteries are taking a pole position in the electrification process. Numerous small and large vessels are being retrofitted or built and several are already in operation.


Edmund Tolo, Market Director Fjellstrand AS, Narve Mjøs, Director Battery Services & projects, DNV GL, and Konstantinos Gagos, project Manager for the Ampere ferry at Fjellstrand AS just before completion

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HIGH SPEED CRAFTS

Recent developments in battery systems and ship electrification hold significant promise for improved vessel performance and the more efficient use of energy. Key industries, such as auto-motive and power, are driving the development of batteries that have increased energy density and cost less. What if this technology was applied on a high-speed light craft (HSLC)? Or even more interesting; what if it was applied on an HSLC Rescue Vessel? Together, NSSR1 and DNV GL want to find out.

The idea is by no means new. The car industry has sold battery hybrid cars for almost a decade and the plug-in hybrid cars that were introduced a few years ago are increasingly popular. Why is this? Is it the reduced fuel consumption? Is the improved performance? Or the environmental profile?

“For a rescue vessel, there are several elements of a battery hybrid power solution that are very interesting,” explains Rikke Lind, Secretary General of NSSR. “Obviously, the prospect of re-ducing fuel costs and our environmental footprint is important. For a rescue mission, the opportunity to run on battery power is very interesting. When arriving at a rescue site, exhaust gas and engine noise will both hinder the rescue personnel and be a problem for the people in distress. With batteries, this could be yesterday’s problem.”

“The operational profile of a rescue vessel is very promising for hybridisation,” states DNV GL’s project manager Sondre Hen-ningsgård. “With a lot of low-speed operation on patrol or dive missions, the use of batteries may greatly reduce not only fuel costs, but also maintenance costs, which are directly linked to the engine running hours. The varying loads at high speed are also ideal for a battery-supported power-production system.”

THE RESCUE VESSEL OF THE FUTURE – a joint effort initiated by the Norwegian Society for Sea Rescue (NSSR) and DNV GL

1 The Norwegian Society for Sea Rescue (NSSR – Norwegian: Redningsselskapet (RS)) is a humanitarian, voluntary member society working for a safe coastline. RS’s purpose is to save lives, salvage property, protect the coastal environment and carry out preventive work in order to improve the safety of people at sea. http://www.redningsselskapet.no/om-oss

Rikke Lind, Secretary General of NSSR

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The joint development project will investigate the feasibility of installing and using a battery hybrid system on a concept rescue vessel, and also the economics involved. The size of the battery, seagoing capabilities, retrofitting, newbuilding and risks in-volved in using batteries are all important elements. “Combining NSSR’s operational and rescue experi-ence with DNV GL’s expert technical knowledge will be a great step towards the use of batteries on high-speed light craft vessels,” says Henningsgård.

“This is the first phase of the project. In the next phase, we hope to involve more partners to further explore and detail innovations for the next genera-tion of greener power solutions. We have no doubts that the results will be a key step towards a safer, smarter and greener future for high-speed light craft vessels!” says Narve Mjøs, DNV GL’s Director Battery Services & Projects.



REQUIREMENTS FOR BATTERY SYSTEMS

weaknesses throughout the development of a new technology and was therefore used to develop the Guideline. The Technology Qualification process

applies a risk-based approach.

The Guideline includes recommendations for all bat-tery-project development phases. Separate sections consider the safety of the battery space, the battery system, the consumers – electrical distribution DC, automation – the Energy Management System and the power input. The Guideline is publicly available for download through the DNV GL Battery and Hybrid Ship service page2.

In DNV GL, we believe in continuous development and improvement. Therefore, and due to the speed of development in this field, we want to further enhance the Guideline. During 2015, DNV GL will facilitate a review and improvement process for the guideline that will include new knowledge and experience. Feedback from all Guideline users is welcomed in this process.


In March 2014, DNV GL published the DNV GL Guideline for Large Maritime Battery Systems. This is the most comprehensive guideline available for such large battery systems. While target applications include hybrid offshore vessels and all-electric ferries and passenger ships, the Guideline’s recommen-dations are also valid for mobile offshore units and most ship types using Li-ion-based battery power in hybrid and all-electric configurations.

The aim of the Guideline is to help ship owners, designers, yards, system and battery vendors, authorities and other third parties during all phases of battery projects. Therefore, the Guideline covers feasibility studies and outline specifications for, and the design, procurement, fabrication, installation, operation and maintenance of, large Li-ion based battery systems. It is consistent with the DNV GL Rules for Battery Power, which shall be applied directly for classification purposes.

Maritime batteries may be more than 100 times as large as electric-vehicle batteries. Their high energy content and extreme charging and operational pat-terns represent new challenges in relation to safety, reliability and service life. DNV GL’s Technology Qualification process1 has proven to be an effective methodology to identify and assess challenges and

1 DNV-RP-A203 Technology Qualification, July 2013: https://exchange.dnv.com/publishing/codes/docs/2013-07/RP-A203.pdf 2 https://www.dnvgl.com/maritime/advisory/battery-hybrid-ship-service.html

DNV GL GUIDELINE FOR LARGE MARITIME BATTERY SYSTEMS



DNV GL GUIDELINE FOR LARGEMARITIME BATTERY SYSTEMSJoint project between ZEM, Grenland Energy and DNV-GLSupported by Transnova

The Guideline was developed in close cooperation with ZEM and Grenland Energy and the extensive work was made possible thanks to financial support from Transnova, now ENOVA.


DNV GL BATTERY RULES

Battery certificationThe batteries on a classed vessel must be certified. The certification requirements are stated in the Bat-tery Power class rules. These rules cover the require-ments relating to battery safety, the Battery Manage-ment System (BMS), the environment and tests. In addition, DNV GL offers a type-approval service for battery systems. This type approval will on a generic level verify that the battery system fulfils the DNV GL class rules’ requirements, including those relating to applicable type tests (safety and environmental tests). The type approval does not replace the “case-by-case” certification, but will limit the scope of this.

Batteries and the Dynamic Positioning rules Yes you can use batteries in DP operations.

The new DNV GL Rules for Dynamic Positioning (DP) systems stipulate requirements for the use of batter-ies as a power source.

The batteries will represent a time-dependent source due to their limited stored energy. DP operations using batteries as one of the redundant sources are limited to operations that can be terminated within the timeframe represented by the batteries’ available capacity.

The battery with its battery management system (BMS) and energy management systems (EMS) must be so arranged that the actual available energy can be deter-mined and communicated to the DP control system.

The class rules cover the use of batteries as part of a vessel’s propulsion energy in either hybrid battery solutions or “pure” battery-driven vessels. The rules have been official since 1 January 2012. A new revi-sion of the rules will be published in 2015.

Battery safetyThe battery rules cover battery-installation safety re-quirements relating to the vessel’s arrangement and environmental controls, including of temperature and ventilation.

To prevent thermal incidents in battery spaces, the rules stipulate requirements as to fire integrity, detec-tion and extinguishing measures. The whole battery installation must be covered by a safety assessment that takes into account internal failures, ie, failures in the batteries, and external failures, like fires and flooding.

Battery powerWhen the battery is used as a main source of power (propulsion power), the redundancy requirements for “ordinary” ships apply. The rules stipulate the required location of the battery systems and asso-ciated electrical systems. An energy management system (EMS) must be installed and control the avail-able energy and state of health (SOH). In addition, the battery’s energy-supply time or range must be calculated and taken into account in the planned operation/voyage.

Yes, DNV GL has class rules for battery-driven vessels and large lithium-battery systems.

REQUIREMENTS


The DP control system (consequence analysis) is to consider the average power and thrust consumption. The calculations of available energy (and then back-up time) are to be based on the prevailing weather conditions and experienced operating pattern, for example the mean net power consumption during the relevant timeframe of the actual operation.

Any uncertainty in the accuracy of the state of charge (SOC) and state of health (SOH) must be accounted for by the use of “conservative” time estimates. In ad-dition, it should be evaluated at which level of charge the battery should be considered to be empty.

It must also be considered if the termination process will result in additional power consumption. In such cases, this additional consumption needs be taken into account as well.

A DP vessel that uses batteries as one of its redun-dant power sources must comply with the Rules for Battery Power and have the class notation BATTERY POWER.

Battery installations on DP vessels that are not used as an energy source, but only used for peak shaving, handling dynamic responses in the power system, etc, may not have to comply with these “battery DP” requirements.


The new DNV GL Rules for Dynamic Positioning (DP) systems stipulate requirements for the use of batteries as a power source.

Sverre Eriksen

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The content of this service document is the subject of intellectual property rights reserved by DNV GL AS (“DNV GL”). The useraccepts that it is prohibited by anyone else but DNV GL and/or its licensees to offer and/or perform classification, certificationand/or verification services, including the issuance of certificates and/or declarations of conformity, wholly or partly, on thebasis of and/or pursuant to this document whether free of charge or chargeable, without DNV GL’s prior written consent. DNVGL is not responsible for the consequences arising from any use of this document by others.

The electronic pdf version of this document found through http://www.dnvgl.com is the officially binding version.The documents are available free of charge in PDF format.

DNV GL AS

RULES FOR CLASSIFICATION

ShipsEdition July 2015

Part 6 Additional class notations

Chapter 2 Propulsion, power generation andauxiliary systems

The class rules cover the use of batteries as part of a vessel’s propulsion energy in either hybrid battery solutions or “pure” battery-driven vessels. The rules have been official since 1 January 2012. A new revision of the rules will be published in 2015.


DNV GL CLASSED BATTERY ELECTRIC AND BATTERY HYBRID VESSELS

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SAFETY ISSUES – A SAFE INSTALLATION

How to prevent critical firesSeveral measures can be implemented to prevent a thermal runaway that could lead to a fire. Passive fire safety, such as protecting battery systems from external loads and preventing thermal propagations between cells, should be provided. In addition, tem-perature control by the Battery Management System (BMS) and ventilation/cooling should be implement-ed. Keeping the environmental temperature con-trolled will also increase the battery lifetime.

To protect against external fires, the batteries could be located in a space with fire integrity that limits the external heat reaching the batteries. In addition, no high temperature and “high fire risk” equipment should be located inside the battery space.

When it all goes wrongMechanical ventilation that extracts possible gases should be considered. The ventilation duct should be able to extract hot gases directly to “free air”.

One of the challenges is to identify a suitable fire- extinguishing medium. The different lithium battery chemistries will produce different gases during a fire. Many of them will produce enough oxygen to main-tain their own fire. The optimal fire-extinguishing medium is one that can supress oxygen while also cooling down the batteries.

This should be documented by a Safety Assessment with the following steps:1. Identification of hazards, a list of all relevant accident scenarios with potential causes and outcomes2. Assessment of risks, evaluation of risk factors3. Risk control options, devising measures to control and reduce the identified risks4. Actions to be implemented

The safety assessment shall be based on the actual battery that is going to be used. Different battery types have different safety properties.The safety assessment should cover all potential hazards represented by the type (chemistry) of battery and at least include the:

■ gas development risk (toxic, flammable, corrosive) ■ fire risk ■ explosion risk ■ necessary detection and alarm systems (gas detection, fire detection, etc) and ventilation

■ external risks (fire, water ingress, etc) ■ loss of propulsion or auxiliary power for essential or important users

Measures are to be identified and implemented to reduce the risk of a hazardous situation to an accept-able level. A hazard can be reduced by lessening either its consequences or its likelihood. This is illus-trated in the figure: Consequence/unacceptable.

The arrangement of the battery spaces must be such that the safety of the passengers, crew and vessel is ensured.

REQUIREMENTS


The use of a portable fire extinguisher should be considered, but bear in mind that the battery installations are large and the extinguishers have limited fire-extinguishing capacity. In addition, large amounts of smoke/gas may be released into the battery space, so that one’s personal safety must be

considered before entering the room. The portable fire extinguisher should not be used as the primary extinguishing method.


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SERVICE LIFE ASSESSMENTS

This figure demonstrates the detrimental effects of keeping a battery at a higher SOC, as well as the devastating impacts that higher temperature can cause if it is not regulated. Understanding these types of relationships is key to selecting and de-signing an energy storage system that can meet the performance expectations for its intended life.

BatteryXT is a software tool that enables our custom-ers to better understand battery technologies and the capabilities those systems bring to their intended application. More specifically, it provides the ability to assess the likelihood of the battery meeting its intended specifications for the duration of its service life.

DNV GL has years of experience in the characteriza-tion and performance assessment of batteries, espe-cially those with modern chemistries such as lithi-um-ion. This experience has led to an understanding and appreciation of the key aspects driving battery capability. Often the most important factor regarding battery performance, yet also the most frequently overlooked, is battery lifetime. This question drives the value proposition and dictates the key insights necessary for comparing technologies.

The question of how long a battery will last depends heavily on a large number of interrelated factors including temperature, sizing, use profile, control system and the chemistry and manufacturing of the battery itself. DNV GL has engaged in both exper-imental and analytical efforts to understand these aspects and be able to provide the answers and solutions needed by customers. The figure to the right illustrates how the amount of battery capacity available after 5 and 10 years depends on two key variables – temperature and State of Charge (SOC).

Estimate the impact of temperature and cycling on battery lifetime and use this data to assess the likelihood of the battery meeting its intended specifications for the duration of its service life.

A snapshot of how much battery capacity would remain after five and ten years based on different temperature and State of Charge (SOC) values.

REQUIREMENTS


The relationship shown in the figure above is a snapshot of the effect of one subset of parameters on battery service life. The full spectrum of these parameters are brought together in the life estima-tion model BatteryXT. With its main interface window shown in the figure above, BatteryXT is designed to enable the evaluation and comparison of any given intended battery application. In order to effectively do so, any such tool must have the ability to:

■ Accept a range of duty cycle characteristics ■ Accumulate the effect of temperature on duty cycle on the total lifetime

■ Account for both calendar and cycling compo-nents of battery capacity fade

■ Provide inputs for battery sizing and a reference state of charge to be used for computing initial and final battery states for the duty cycle

BatteryXT was designed specifically to meet these requirements. Users can upload a use profile of

their own designation and then select the battery parameters they would like to evaluate – including battery chemistry, known temperature and cooling conditions, as well as sizing. This functionality yields a tool able to help system operators select technology and evaluate key aspects of design and operability. The model can be custom tailored by DNV GL to a given battery chemistry of interest and then used to evaluate any given range of use profiles.

BatteryXT provides a way for our customers to better understand this technology and what its capabilities are with regard to any potential use profile – allowing for innovation and a safer, more sustainable meth-od of operation. The end result is a battery system evaluated specifically for the particular application of interest and an owner that is confident in the system.


The main graphical interface window of BatteryXT shows inputs (on the left) enabling the definition of any operational parameters for an application, as well as the resulting profile and expected lifetime predicted by the model (right).


MARITIME BATTERY FORUM

The Maritime Battery Forum was established in April 2014, based on a DNV GL initiative. The 45 members are private companies, authorities and R&I organiza-tions within the maritime sector. The members’ am-bitions to cooperate on the development of battery competence and new solutions were key drivers for establishing the forum.

The members represent the whole value chain, from battery manufacturers to end users. They benefit from working together to develop new and improved stor-age solutions and applications. For example, battery suppliers need to know more about rig and vessel operations to understand how a storage system can add value for owners and operators. Owners and op-erators need a better understanding of the potential operational cost reductions that a storage system can give them. Maritime Battery Forum seminars and meetings create a meeting place and connect the members, facilitating cooperation and the develop-ment of new knowledge and solutions.

The forum works on several levels to achieve its vision of making the Norwegian maritime cluster world leading within battery-based value creation. In addition to being an important meeting place for the members, the forum works to improve incentives and mitigate barriers to storage technology uptake. The efficient communication of storage technologies’ potential for further innovation, emissions reductions and business development to politicians and policy implementation organizations is important. This is

in order to secure a public framework and financial incentives that favour the use of maritime battery solutions and appreciate the value of the environ-mental benefits.


■ Member meetings twice a year with knowledge sharing and discussions

■ Conference once a year ■ Database of ships with battery technology ■ Database of relevant battery accidents (ongoing project)

■ Web portal: - News service - Relevant documents - Presentations from member meetings

ACTIVITIES:

■ Egil Holland, Chairman of the Board ■ Ingar Skaug, Board member ■ Remi Eriksen (COO DNV GL), Board member ■ Jan Fredrik Meling (CEO Eidesvik Offshore), Board member

■ Synne Opsand, Managing Director

BOARD MEMBERS:

MAKING THE NORWEGIAN MARITIME CLUSTER WORLD LEADING WITHIN BATTERY-BASED VALUE CREATION


Synne Opsand, Managing Director Maritime Battery Forum.

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Our vision is to make the Norwegian maritime cluster world leading within battery based value creation.

www.maritimebatteryforum.com


DNV GLDriven by our purpose of safeguarding life, property and the environment, DNV GL enables organizations to advance the safety and sustainability of their business. We provide classification and technical assurance along with software and independent expert advisory services to the maritime, oil and gas, and energy industries. We also provide certification services to customers across a wide range of industries.

Combining leading technical and operational expertise, risk methodology and in-depth industry knowledge, we empower our customers’ decisions and actions with trust and confidence. We continuously invest in research and collaborative innovation to provide customers and society with operational and technological foresight. With our origins stretching back to 1864, our reach today is global. Operating in more than 100 countries, our 16,000 professionals are dedicated to helping customers make the world safer, smarter and greener.

DNV GLBrooktorkai 18, 20457 HamburgGermanyTel: +49 40 361490

DNV GL ASNO-1322 Høvik NorwayTel: +47 67 57 99 00

www.dnvgl.com

The trademarks DNV GL and the Horizon Graphic are the property of DNV GL AS. All rights reserved.© DNV GL 800/05-2015 Design: CoorMedia.com 1504-044 Print: CoorMedia.com

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Battery powered ships

Engineering