Exploring the Feasibility of Alternative Fuels and Technologies for Cleaner Shipping
1.2 Problem Statement
The emissions from shipping activities are currently not regulated in the Kyoto Protocol or in the EU agreement to lower greenhouse gas (GHG) emissions. Given the global nature of shipping and the potential for shipping companies to avoid regulation by refueling in non-participating countries, there is concern that GHG emissions from shipping could increase substantially if not regulated. By 2020, emissions of GHGs from international shipping could grow by between 77% and 95% above 1990 levels. If left unchecked, emissions from international shipping could grow by 250% by 2050.
The Stern Review on the Economics of Climate Change states that the total externality cost of CO2 in 2007 is between $85 and $253 per tonne of CO2 (at 2007 prices). If a tonne of CO2 is costing the world between $85 and $253 in damages and there is potential for shipping emissions to grow by 250% by 2050, the externality costs to the world of emissions from future shipping activities could be in the trillions of dollars. This is a large cost to impose on the world community from one sector and ships built today will be operating for the next 25-30 years. With greater public awareness of environmental issues, there is potential for consumers to reward those companies that embrace clean technology and fuels sooner than anticipated. This is a potential competitive advantage for early movers.
1.3 Objective
With increasing pressure from international legislation for a reduction of greenhouse gas emissions and growing concern of climate change, shipping industries are considering exploring further potential alternative fuels and technologies that can both help in cutting down the emissions and complying with the legislations and will enable shipping to continue its service to society. This is to the knowledge of the researchers that this detailed information on the feasibility study of all potential alternative fuels and technologies for the shipping sector in the EU has not been done before. And this research work will be able to provide a database of the potential alternative fuels and technologies and their feasibility critiques. This will enable the shipping industry to make a clear choice on a more environmentally friendly fuel and technology that it can use in the short term and long term future and any further legislations on the specifications of the fuels and technologies. This research work is to be done over a course of 3 years starting in 2016 and is also to the best knowledge of the researchers that the technology trends will not take a massive shift like how it has changed in the past 10 years. This study is expected to be valid for the next 10-20 years.
On the other hand, the maritime sector is also known for its large consumption of fossil fuels and its impact on the environment and thus human health. Global shipping is responsible for 2.7% of total CO2 emissions, which is about 760 million tons, and the EU’s share is 20.9% of the emissions. A slightly lower percentage of emissions is caused by domestic shipping, but emissions from domestic shipping tend to have a greater impact due to operating in more eco-sensitive areas such as coastal zones and the contribution to local air quality. Both international and regional shipping emissions are expected to increase in the future.
The main objective of the research described in this thesis is to explore different alternative fuel and technology options for cleaner shipping in order to reduce the emissions of the shipping industry. The shipping industry is very important for the world economy. Over 90% of the world’s trade is carried by sea. Shipping is the lifeblood of the global economy. It is a crucial part of our society and has a significant impact on the world.
2. Literature Review
The literature reviewed was quite incomplete and often focused on the alternative fuels themselves, providing significant findings for sections 2.1 and 2.2. It was often difficult to separate fuel technology from engine technology and so these will be discussed interchangeably where appropriate. Literature on the environmental impacts of shipping is scattered and limited, often providing bullet point lists rather than comprehensive studies. This section also proved difficult to compile findings due to the incongruent nature and results of many studies.
This section explores the current technological and fuel-based solutions for reducing the environmental impact of the shipping sector. Ballast water treatment and hull cleaning are types of maritime environmental solutions not covered in this thesis. These have important consequences for emissions, but have been omitted due to their marginal relevance to the core propulsion of the vessel.
2.1 Overview of Alternative Fuels for Shipping
The prime mover of the ship has been fueled by oil, which serves to rotate the propellers for the ships to move since the S.S. Savannah initiated the first crossing of the Atlantic Ocean by a steamship. Oil fueled the shipping industry from that point onward. The industry has expanded greatly in the volumes of goods that are being transported as globalization set in. It can be said that the shipping industry is a foundation of the economic infrastructure of globalization due to it being a principal method of moving goods from one place to another for exportation or importation. Therefore, oil has been the foundation of fueling the economic backbone of globalization. Oil will remain to be the predominant fuel for the shipping industry, with a huge majority of merchant ships around the world being propelled by the means of marine diesel oil. The usage of oil as a fuel for ships has drastically increased the environmental implications posed by the shipping industries. In recent times, the pressure applied by various environmental groups to reduce the impact of global warming has caused the scientific community to address such issues. From this, we are presented with the option of seeking fuels alternative to oil, which are more environmentally friendly and sustainable. This concept has been adopted by other industries looking to reduce their environmental impacts, and shipping is no exception. Today, there are several forerunning prototypes and concepts of alternative fuels, exemplified in the following summaries, are in various stages of development. In this context, an alternative fuel is an energy form different from oil and its derivatives, i.e. not using diesel fuel.
2.2 Advantages and Disadvantages of Alternative Fuels
The global warming impact of CO2 emissions from fossil fuels has led to increasing pressure to move towards the use of carbon-neutral or renewable energy sources. A recent study has estimated that a global cap and trade system for CO2 emissions will be a major driver in increasing demand for energy from renewable sources and nuclear power (Corbett and Wang, 2006). Renewable energy sources are those which are naturally replenished, and an ideal carbon-neutral energy source would be one which has zero net CO2 emissions. This concept is vital in meeting the needs of a growing future global energy demand while maintaining the aims of the Kyoto Protocol and future CO2 reduction commitments. Currently, there are two main limitations to the use of renewable energy sources in shipping. First is the limited and expensive availability of marine renewable energy systems, and the second is the considerable capital cost and time required to develop new renewable energy systems for the marine industry.
Using alternative fuels in shipping has some inherent advantages and disadvantages. The most important advantages are associated with the reduction of SOx, NOx, and particulate emissions, all of which have an environmental and/or human health impact. The reduction of these emissions is the main driver behind international and national legislation concerning vessel air emissions. It is widely recognized that the most effective way of reducing these harmful emissions is to move to distillate fuels (MARPOL, 2008). However, a move to distillate fuels for all vessels would have the effect of increasing demand and therefore price for these fuels. One alternative which is already available for reducing emissions is the use of low sulfur fuels, either through blending with MGO or MDO, or with the more recent development of pure LS MGO. The LS MGO option is effective, but the fuel is more expensive than standard MGO and has associated production emissions which may counteract the emissions savings depending on the source. An alternative cheaper method is the installation of a SOx scrubber which allows continued use of HFO/MDO/MGO but with reduced emissions. The long-term sustainability of these options is questionable due to the limited availability of crude oil and an anticipated increase in prices. Other methods of reducing emissions include engine modification or fitting, or the change to completely different fuel types.
2.3 Technological Innovations for Cleaner Shipping
A change of fuel can be said to improve efficiency if it reduces the fuel cost for a given amount of energy obtained. This is essentially what the aim of CIGS which proposed a global switchover to nuclear shipping in the 1950s. Although there are clear reasons why nuclear power is not suitable, the essence of the idea is correct. Nuclear power has been suggested as an option for emissions-free shipping future. However, the sustainability of this option is in doubt given the high cost and safety concerns, and so attention is focused on renewable energy sources such as biodiesel, bioethanol, and methane.
In terms of fuel, changes can be made to both the type of fuel used, and the way in which the energy is converted into propulsive power. The most immediate way of improved efficiency is to use a high-efficiency version of the existing 2-stroke engine, combined with improved propeller design. However, the long-term future for ships is likely to be with alternative propulsion systems such as air-lubricated propulsion, and much further down the line, full electric propulsion.
Efforts to improve the efficiency of shipping can take several forms. First, a more efficient engine and propulsion system can be developed. This is an ongoing process for the major engine manufacturers such as Wartsila, MAN Diesel and General Electric. Steady advances have been made with traditional diesel engines. However, the holy grail for engine development is the successful adaptation of fuel cells and hydrogen technology. These have the potential to be significantly more efficient than internal combustion engines, and with no net GHG emissions. The way is also open for development of more unconventional systems such as the turbine-based COGAS system unveiled by Mitsubishi, and ocean-going solar or wind-powered ships.
Many of these measures have the potential to reduce the fuel consumption of ships by over 10%. However, the measure with the largest potential is improved energy efficiency.
Technological innovations and R&D are seen as crucial elements of sustainable development of shipping. There are a number of technical measures which are available for reducing the GHG emissions of ships. These can be broadly categorised as operational, speed and propeller optimisation, improved cargo handling, wind assistance, hull and propeller cleaning and maintenance, and improved energy management.
2.4 Environmental Impacts of Current Shipping Practices
The adverse environmental impacts associated with the shipping industry will continue to grow as global demand for goods transport rises and the industry continues to expand. The most notable impact from shipping is the introduction of invasive species into new environments. This can occur in a number of ways, one common approach is for ballast water to be taken up in one region after unloading cargo and then released in another region when different cargo is loaded. The discharge of ballast water can have varied effects from substrates to clear water habitats and can cause ecosystem unpredictability by allowing colonization of a new species into a habitat which it wouldn’t normally occupy. The transfer of aquatic invasive species poses both ecological and economic risks, and has been identified as one of the four greatest threats to the world’s oceans, according to the 2007 UN environment programme.
Currently, the global shipping industry uses petroleum-based fuels in diesel engines. Heavy distillate fuels are used by large vessels and light distillate fuels in small high-speed craft. These fuels are not the cleanest burning and can produce noxious exhaust. The refinement of these fuels has improved over time from simple distillates to hydrocracking and more recently the development of low sulfur fuels with further post-combustion emission control to lower particulate matter and NOx emissions. However, carbon dioxide is directly related to the quantity of fuel consumed. There is currently no viable fuel alternative which can replace petroleum-based fuels, and the only potential is to improve fuel consumption with further development in technologies and increased energy efficiency. Simulation studies have shown potential to reduce emissions by as much as 75% with slow steaming and improved fuel consumption.
3. Methodology
The first important aspect of the methodology is to pinpoint the assumptions made all the way through the study. Most of the future market data will be assumption-based and hence it is impossible to produce an accurate figure. The only way to make an assumption valuable is to compare it with a current day to see if the assumption is valid. If not, it will have to be modified until it can give a somewhat accurate prediction. This also means that if the assumption has been made on a future alternative fuel, it should be compared with the current MDO/HFO setup as it will be the benchmark for the comparison. By knowing this, we must still make a decision on what specific engine or power plant setup we assume the alternative fuel will be used with. This is important because an older 2-stroke engine technology will still be quite prevalent in the marine industry compared to the modern diesel engines and hence the decision-making tool must provide a correct comparison for the different engine technologies. At stages through the study, there will be some assumptions made that are outside the scope of the decision-making tool and hence a probability Impact matrix will be used to assess the impact of the event connected to the assumption. This will still give a quantitative value.
This part of the essay is to provide detailed information on the methodology of the research. It will explain the research design, data collection, and data analysis for the study and also the case study used to illustrate the points. The methodology is important because the reliability of the results is dependent on whether the means of the study is valid and also the many assumptions made in calculating the many values in the study. A correct methodology will then ensure that the decision-making tool produced will be reliable. This will be crucial because it will help the stakeholders of the decision-making tool in being convinced that the tool is indeed useful in making a structured decision and also to push them to adopt an environmentally friendly fuel for their ships in the future.
3.1 Research Design
Simulation models created for both hypotheses will be used to make comparisons of expected investment decisions with today’s decisions. HFO, a likely sunk investment, can be classified as a 100% endeavor, so any near future potential consumers of HFO will wish to compare the longevity of the product with expected regulation. This decision-making comparison will provide an indication of the potential transition period to cleaner fuels and technologies. Any discontinuations of new build ships or retrofitting of existing ships can be classed as an unserved market demand, which leads to opportunity costs. The models will provide a thorough understanding of industry response, and a prediction can be made of the achievement of the mission to clean up the industry. These will act as a series of go/no-go decisions that guide the movement of shipping towards our identified cleaner future and can be tested at specific intervals of time for periodic analysis of the improved feasibility and progression of technologies.
The second hypothesis aims to provide an assessment of the feasibility of the implementation of said technologies given increased market demand. The Technologies and Innovation theory will be used to assess the dynamic between the push of increasing regulatory stringency on pollution and the pull of market demand for more environmentally friendly ships. This will require the development of a typology framework to classify ships by type and application of a method to assess the rate of technology transfer between new and existing vessels. With constraints likely to be placed on pollutant discharge from specific dates in the future, a simulation model of the effect of likely regulation on the price elasticity of demand for specific propulsion systems and alternative fuels can be produced to provide information on the expected change in investment decisions for new builds and retrofits.
The research will begin by testing the preliminary hypothesis (H1) that environmental regulation and potential future taxation of HFO will create a market pull for more sustainable propulsion systems and alternative fuels. This will be supported by providing an overview of the current state of the industry and an analysis of stakeholder perceptions on this issue. Data collected from qualitative interviews and articles/reports will help to construct an analysis of HFO prices and price elasticity of demand, create a simulation model for price scenarios, and outline expected investment decisions for new builds and retrofits of existing vessels. This will provide a comprehensive understanding of the impact of regulation on demand for propulsion/fuel technologies.
The research design follows a deductive approach. The research is framed around the identification of current barriers to and future prospects for the use of alternative fuels and propulsion systems in shipping. This is approached through the testing of two hypotheses with supporting secondary research and original analysis of qualitative data. The aim is to produce concrete and data-driven assessments of the feasibility of the implementation of these technologies, with the end goal being to further research and development within this area.
3.2 Data Collection and Analysis
The findings that form the basis of this paper have been gathered and assimilated through a variety of literature, analysis, and the expert knowledge of those in the marine propulsion industry. This thesis has attempted to provide a comprehensive overview investigating the feasibility of alternative fuels and technologies for cleaner shipping. In order to form an accurate view on the relevant issues, it was important to utilize as wide a range of information as possible, taking into account various opinions about different types of fuels, the successes of current and emerging technologies, and the ways in which different policies will influence the business strategies of shipping companies. Given that the majority of information about future shipping technologies is forward-looking, the usage of expert knowledge was particularly valuable in providing some insights for what may happen in the future. As such, the value of expert interviews was high. Unfortunately, interviews with technical personnel in the shipping industry are difficult to obtain due to the nature of their work and the fact that there are relatively few experts specifically in the engine technologies for ships. This is an area in which further research may yield some interesting insights. In addition to this, a cross-sectional analysis of different companies both in the context of case studies and from general data will help in understanding how different firms will react to the changing economic and political landscape in the shipping industry.
The main body of the research undertaken between the period of December 2016 and August 2017 has been through studying current and past technology in shipping and comparing this with energy supplies and related ship design. This has been done through literature pertaining to different technologies and their applications, paired with analyses based around economic viability and the potential pitfalls and benefits of each technology. Static comparisons between different types of fuels and technologies have been conducted as well as attempts to predict the future based around the concept that certain patterns in the shipping industry are likely to remain as a result of previous work conducted through discussing with industry experts. Energy supplies and shipping designs were compared over similar methods and some very general predictions have been made about future shipping designs compared to current or known future technology. Data analysis has been a key feature of this section and has often been collected in a somewhat crude fashion when compared to clinical data collection in the natural sciences due to the highly varied and sometimes abstract data that has been compared. Open-ended questioning was utilized in discussions with industry experts and attempts to bring structure to this were often met with only partial success due to the unpredictable nature of open-ended questions.
3.3 Selection of Case Studies
Case Study 2:
This was a study of a Norwegian environmental pressure group which had been actively involved in shipping issues since the 1970s. This group was selected as from the start it was quite clear that its members had a very detailed understanding of the issues and how to influence the outcomes in the shipping and shipbuilding sectors. Due to the resources of the group having to be concentrated in central Norway, its influence has been felt largely in the offshore and fishing vessel sectors. This information was gleaned mainly from formal and informal interviews with the group’s members, and it provided a guide as to what can be changed in the decision-making processes regarding ship design and operation and how this can be influenced to achieve a desired outcome in terms of environmental impact.
Case Study 1:
This was a study of a well-established shipping company with a fleet of 7 vessels, which are of mixed age and type and involved in worldwide tramping operations. This company was chosen as the owner provided access to all relevant information and made available considerable time to discuss the issues with the researcher. The information from this case helped to isolate the key decisions made by ship owners in the various parts of the shipping market. From this, it was possible to paint a very detailed picture of how legislation and other external pressures are transformed into ship design, operation, and scrapping decisions.
Two cases were selected, which are summarized briefly below.
To achieve the aims of the research and to enrich its outcomes, it was decided that case studies should be undertaken. There is a wide choice of cases that could have been studied ranging from the very small to the very large. In the time and with the resources available, it was necessary to limit the scale of the case that could be studied and to choose those that would bring the greatest benefit to the research in terms of input and insight into the issues facing shipping and the environment.
4. Findings and Analysis
4.1 Feasibility of Alternative Fuels in Shipping
The study identifies several potential alternative fuels, however it is apparent that much of the industry considers LNG to be a transitional solution at best. Given a high level of concern over methane slip and the global warming potential of methane, the merits of LNG remain questionable. Findings indicate a notable trend towards development of biofuels. These are seen as a viable solution due to the similarity in handling and combustion with existing HFO. However, doubts have been raised over feedstock availability and the potential impact on food prices from widespread biofuel use. Moving further from current fossil fuel technologies, nuclear power has been touted as a potential future energy source for ships. Despite being a proven emission-free technology, opposition to nuclear power is high in some quarters, there are concerns over safety and the possible implications and costs of a large-scale switchover to nuclear power within the industry. On a similar note, solar and wind power were seen as clean and free energy sources. However, the viability and scalability of such technologies for merchant shipping, the primary concern of the project, are low. This is due to the space and payload requirements of solar and wind-powered systems conflicting with the need to transport goods cost-effectively in today’s highly competitive markets.
Developments to meet MARPOL Annex VI will reduce harmful emissions from ships, resulting in a significant reduction of air pollution and its associated impacts on the environment and human health. The exact solution to this requirement in terms of alternative fuels remains unclear.
4.1 Feasibility of Alternative Fuels in Shipping
Engagement of waterborne vehicles will increase unless global carbon levels decrease, simply because carbon levels are increasing faster than the improvements in energy efficiency. Therefore, changes should be made in the type of fuel to one with a lower carbon content. Fuels considered to be used in the marine industry with lower carbon levels (and therefore lower GHG emissions) include natural gas, liquefied natural gas (LNG), methanol, and biodiesel. Of these, natural gas is seen as an attractive fuel, as LNG is the only fuel expected to meet the IMO’s MARPOL Annex VI NOx emission standards within the next decade. This is important because NOx is a pollutant that has a particularly strong impact on the atmosphere. LNG and biodiesel have the benefit of being drop-in fuels, therefore making it easy for vessels to transition from traditional diesel. This is an attractive feature as it would reduce the economic risk for shipping companies to make the switch to a lower carbon fuel. However, both these fuels do face safety and storage issues, as well as increased total GHG emissions when methane release is considered. Considering all these factors, it is predicted that over the next 20-30 years there will be a move from oil-based fuels towards more efficient and low carbon fuels such as natural gas. This is due to an expected increase in the price of traditional marine diesel making the competitive alternative more attractive.
4.2 Effectiveness of Technological Solutions
The effectiveness of various technological solutions to reduce the emissions of CO2 and other pollutants from ships has been assessed to identify the most practical and affordable solutions for 2030 and beyond. This involved a careful evaluation of the potential of new fuels, energy sources, and various engine and propulsion technologies. The study was necessarily broad at this stage, given the lack of detailed data on the many specific technologies at early stages of development. It was based on the potential availability and characteristics of various fuels and power sources to provide an indication of the types of technology that might be feasible in the future. An initial quick assessment was made of the potential of technical and operational measures to improve in-service fuel efficiency for the existing fleet, taking into account the age of the ships and their typical trading patterns. This is because fuel efficiency improvements of the existing fleet can provide quicker reductions in CO2.
4.3 Economic Considerations
With the current financial climate in the shipping industry and anticipated cost increases, it is possible that some ship owners may choose to scrap their ship rather than retrofit or repower to meet emissions requirements, particularly for older vessels, and this could be the era of technological shift from existing fleet to newbuild. In stock-flow models used to depict the evolution of the ships and the associated emissions, older ships are replaced more rapidly with the stricter global regulations in place. Transition scenarios for types of ships and engines should be approached differently because a gradual implementation of stricter regulations provides time for industries to develop the technology. For example, the implementation of an early regulation for Tier II NOx limits by 2011 and a later regulation for Tier III 8 years thereafter provides ample time to develop promising natural gas technology. However, more drastic future regulation changes with partial fuel bans and/or engine standards in ECAs may force an immediate shift in the type of fuel used. This would entail shorter lives for the current type of engines and incur costs from scrapping or early replacement of ships. Strategies could be further analyzed through policy and affect the optimal path of the global shipping fleet.
Economic analysis compared the four technologies of marine fuel cell, natural gas combined cycle, ultra low sulphur diesel (ULSD), inlet wet scrubber and found that all are more expensive than the conventional marine heavy fuel oil (HFO) and taking into consideration the caveat of tighter global sulphur cap by 2020, the price gap between HFO and cleaner alternative will widen even further. It is expected that newbuild ships could meet the Tier III NOx emission standards through internal engine modifications and the use of ULSD for roughly a 20% increase in price compared to the ship built to meet Tier II emission standards. Tier III NOx compliant engines and ULSD also provide a step towards achieving future GHG reduction targets because there is a direct relationship between engine efficiency and fuel consumption.
4.4 Environmental Benefits and Challenges
In the context of environmental and sustainability issues, the impetus for the study into alternative fuels and technologies is ultimately to lessen the undesirable environmental impacts of the shipping industry. The types of fuel burned in an engine and the technologies used to abate emissions have a direct impact on the environment. There are the obvious local effects of pollution in and around heavily trafficked port areas, but increasingly there is concern over global effects from shipping emissions. The relatively low quality of residual fuels used in shipping (300 cSt and 700 cSt) means that emissions of criteria pollutants such as SOx, NOx, particulate matter and unburned hydrocarbons have high adverse effects. Moreover, the greenhouse gas (GHG) emissions from shipping, CO2 and methane, are a growing concern for the environmental impact of shipping in comparison to other modes of transport. Alternative fuels and abatement technologies have varying potential to lessen these emissions and thus the environmental impacts from shipping.
The use of alternative fuels presents a direct method of reducing criteria pollutant and GHG emissions from shipping. The extent of the benefits is dependent on the type of fuel used. Liquefied natural gas (LNG) has received a lot of attention in recent years for its potential to replace conventional bunker fuels in shipping and in some cases substantially reduce emissions. Studies have shown that compared to conventional fuels, LNG can result in 80-90% lower NOx and SOx emissions and 15-25% lower CO2 emissions. These data are largely dependent on the engine type and can vary, but in general, LNG has favorable emissions compared to conventional fuels. This is a result of natural gas having lower carbon content and other contaminants detrimental to combustion and emission. The downside to LNG is that though it is cleaner, it is a limited non-renewable resource and there can still be methane slippage during storage and fuel transfer to the engine. Methane is a potent GHG, and studies estimate that if there is greater than 2% slippage, then the overall impact on global warming of using LNG can be worse than diesel.
5. Conclusion
An interesting result in the case study was the use of biomass-derived methanol as a fuel, which is CO2 neutral. However, due to the nearly double cost of MDO and methanol driven by the higher price of biomass compared to derivative products today, plus the fact that no carbon tax or other incentives were applied in the scenario, it was not economic to switch to methanol. This could be subject to change in the future price of methanol and MDO.
It has been shown through a case study applied to a Panamax bulk carrier that the ship types with longer round voyage durations sailing at lower speeds will be the most suitable for alternative fuels. This is mainly due to the fact that many alternative fuels have less energy content than traditional bunker fuel. Thus, the higher the fuel consumption of the ship and the more expensive the fuel used, the more economic sense it makes for alternative fuels. It has also been shown that due to the price premiums of alternative fuels over MDO, government intervention in the form of a carbon tax and/or substantial subsidies will accelerate the adoption of alternative fuels in the quest for GHG reductions in the industry.
Norway has been a forerunner in the development of LNG as a fuel and has a highly publicized vision of creating a “short sea shipping” concept using LNG as the fuel and building a series of LNG-fueled ships. This may be a niche market development in the changing energy landscape in the world, but it is less of an option for the deep-sea merchant fleet which forms the backbone of globalization.
This paper has addressed the options available for cleaner shipping technology, including alternative fuels and energy efficiency technologies. A lot of research has been done in the field of alternative fuels, such as Liquid Natural Gas (LNG) and Liquefied Petroleum Gas (LPG). It has been determined that to date there is no one alternative fuel that will be suitable for all ship types, sizes, and trades.
5.1 Summary of Findings
The various technologies and alternative fuels outlined as potentially feasible means for reducing air emissions and GHG from shipping are evaluated by the EMEP model for IMAFT in 2000. The model provides a relatively quick means of comparing the relative environmental merits of various technologies and fuels. Key findings include the low impact of Marine Residual Fuel Oil (MRO) desulphurization and distillate fuel oil (MDO) technology changes in CO2 and global warming potential scenarios. This is due to the relatively small difference in specific emissions between the two fuels and the IMAFT assumes a global low-estimation value of MRO leakage to be near 1%. In effect, the sulfur content of residual fuels adds significantly to PM emissions; therefore, a greater reduction in the global warming potential scenario is observed for those technologies and fuels that result in a switching from MRO to MDO. Global fleet speed reduction is found to be a useful strategy in that it creates fuel savings by diminishing time-sensitive shipment inventory and is a relatively direct method that has effects in all emission types. Technique-specific impacts are seen in the comparison of results between main engine and auxiliary engine NOx emission reductions.
5.2 Implications for the Shipping Industry
This analysis has raised as many concerns as it has answered questions. It is clear that in a number of cases, alternative fuels have the potential to severely reduce emissions of CO2 and other pollutants into the atmosphere. Despite this, not all of the alternative fuels are suitable for all types of ships, and so a multi-fuel future may be required. Each individual shipping company will need to weigh the environmental benefit against the operational practicality. For instance, a RoPax ferry service that can conveniently refuel with LNG at fixed ports may opt for this as an alternative to diesel. A company that has invested in a new diesel-electric propulsion system or has a new ship on order may be less inclined to make the switch to LNG. This is due to the fact that the investment in the LNG infrastructure or new gas-fueled ships would be a costly exercise and LNG would not be suitable for retrofit to ships more than 20 years old. For the shipping industry as a whole, the transition to a low sulfur fuel oil is likely to be the most popular method of reducing SOx emissions. This is due to the fact that the global cap will force the use of low sulfur fuels and the availability of distillate fuels means that the impact on current diesel engine ships will be minimal. However, this will still mean a significant increase in costs for fuel and for goods transported by sea. This could lead to price increase for the customer and a shift of some commodities to alternative transport modes. The impact of COVID-19 has already forced some companies to halt or delay installations of EGCS, through a combination of financial strains and regulatory uncertainty. The next few years will be a difficult environment to incentivize an increased investment in alternative fuels or new technologies.
5.3 Recommendations for Future Research
Upon a clear understanding of the technologies, fuels, and policy measures for cleaner shipping, a clear way forward would be to analyze the policies for reducing environmental impacts of shipping. This signifies that the best way is to move away from the use of oil-based fuels and to provide and use long-term and short-term frameworks to help achieve the required results. This would include the analysis of cost-effective options and pricing strategies. Moreover, to lower the environmental impacts of shipping in the future, those alternative policy measures also need to be assessed in terms of the possible CO2 reductions achievable compared to the various restrictions and limitations on fuel types that can be applied. This would provide an overall assessment, allowing informed decisions to be made on the types of measures that should be used in the future to reduce the climate impacts of shipping. This also implies the work done by CARES IT and other similar research in which they are developing a simplified interface of their own model involving the cleaner shipping scenarios, to provide a tool to easily assess the scenarios like those in the MEPC 58 and other alternative scenarios for policy decisions on shipping. This would act as a platform for policymakers and other researchers to assess and compare the various potential scenarios to reduce shipping GHG emissions and find the most effective solutions, taking into consideration the energy demand and relative costs of each measure. Development of alternative energy sources for shipping is a key measure in which assessments need to be made on the various ways by which alternative fuels can be derived from renewable energy sources and a thorough assessment of the engines and vessels that will use them. This should be a continuous assessment until the technologies are near maturity and can be assessed by similar methodologies to the ones used in this study on assessing the energy and environmental profile of the fuel and technology options. An overall assessment will often require a reiteration of similar methodologies to those used in this study as various technologies continue to change and move forward over time.
