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Benefit Analysis

Benefit Analysis of Increasing the Number of Methanol Fuel Bulk Carriers

Outline

To estimate the potential benefits of increasing the number of green methanol fuel ships, an analysis was performed on green methanol-fueled bulk carriers. Bulk carriers were chosen as the ship type to analyze because they accounted for 28% of CO2 emissions from shipping in 2019, the second-largest share of emissions of any ship type.[1]Adamopoulos, Anastassios. “Shipping’s ‘Big Three’ Account for Almost 80% of CO2 Emissions :: Lloyd’s List.” n.d. Accessed November 17, 2021. … Continue reading They also account for the largest single share of deadweight tonne-nautical miles, a unit used to express a tonne of goods carried for one nautical mile.[2]Adamopoulos, Anastassios. “Shipping’s ‘Big Three’ Account for Almost 80% of CO2 Emissions :: Lloyd’s List.” n.d. Accessed November 17, 2021. … Continue reading

The basic outline of this analysis can be summarized as follows: 

  1. Project the total number of bulk carriers each year between 2019 and 2039
  2. Project the number of methanol fuel bulk carriers in a given year
  3. Estimate the direct CO2 emissions of an average bulk carrier ship, often called tailpipe emissions
  4. Estimate the CO2 emissions from the fossil fuels used by bulk carriers that occur before the fuel is burned (e.g., emissions from extraction and refining), often called upstream emissions
  5. Project the lifecycle emissions for fossil-fuel powered bulk carriers for each year between 2019 and 2039 assuming no change in fuel source
  6. Estimate the lifecycle CO2 emissions from a green methanol fuel bulk carrier
  7. Project the total CO2 emissions from all bulk carriers with and without an increase in methanol fuel bulk carriers
  8. Find the amount of CO2 reduction due to the increase in the number of methanol fuel bulk carriers
  9. Based on this reduction and social cost of carbon figures, estimate the benefit derived from reduced CO2 emissions

Detailed Description

Baltic and International Maritime Council (BIMCO), a shipping industry group, predicted in 2021 that the global shipping fleet will grow at 1.25% over the next five years.[3]Sand, Peter. “World Fleet to Grow by 6.4% over the Coming Five Years, down from 7.4% in Previous 5 Years.” 2021. June 24, 2021. … Continue reading While the growth rate for each type of ship will not be the same, this analysis applied a 1.25 annual compound growth rate to the number of bulk carriers for every year between 2019 and 2039 for the purposes of simplifying this analysis.

Projected number of bulk carriers 2019-2039. Graph produced from our analysis.

Next, the analysis estimated the number of methanol fuel bulk carriers in future years.  A target of 12% of all ships being methanol in 2030 was set, and the analysis assumed this would be the same across all ship types.[4]Gallucci, Maria. “Why the Shipping Industry Is Betting Big on Ammonia – IEEE Spectrum.” n.d. Accessed November 17, 2021. … Continue reading This analysis estimated the increase in the percent of bulk carriers running on methanol fuel is linear with respect to time. 

Projected number of diesel (blue line) and methanol (red line) bulk carriers from 2019-2039. Graph produced from our analysis. The number of diesel bulk carriers remains relatively unchanged, but the number of methanol bulk carriers increases with time.

Global maritime shipping emitted about 880 million tonnes, or metric tons, of CO2 in 2019.[5]Khasawneh, Roslan. “Maritime Shipping to Fall Short of Net Zero Emissions Target – IEA | Reuters.” 2021. May 20, 2021. … Continue reading Of these emissions, bulk carriers, also called bulkers, accounted for 28%,or 240 million tonnes.[6]Adamopoulos, Anastassios. “Shipping’s ‘Big Three’ Account for Almost 80% of CO2 Emissions :: Lloyd’s List.” n.d. Accessed November 17, 2021. … Continue reading With about 11,000 bulk carriers in 2019, each bulk carrier averages a total amount of yearly CO2 emissions of 0.022 million tonnes.[7]“Benchmarking Bulk Carriers: 2019-2020.” n.d. International Association of Dry Cargo Shipowners. https://www.intercargo.org/wp-content/uploads/2021/03/INTERCARGO-Benchmarking-Report_2019-20.pdf. To estimate the tailpipe emissions from bulk carriers, the predicted number of bulkers each year was multiplied by the estimated emissions per bulker to project the emissions from all bulkers in every year between 2019 and 2039.

While emissions from the direct burning of fuels on ships are important, they are not the only source of CO2 emissions from fuel usage. Fossil fuel extraction, transportation and refining all emit CO2 which must be accounted for to get a full picture of the CO2 emissions from using a particular fuel.

To estimate the total amount of fuel usage reduction as a result of using methanol-powered ships, this analysis estimated the amount of fuel used by bulk carriers in 2019. It multiplied the percent of ships that were bulk carriers in 2019, about 21%, by the total amount of marine fuel used in 2019, 210 million tonnes.[8]Placek, Martin. “Amount of Fuel Consumed by Ships Worldwide by Fuel Type 2020 | Statista.” n.d. Accessed November 18, 2021. … Continue reading This yielded a 44 million tonne fuel use estimate for bulk carriers in 2019. This used the simplifying assumption that a ship type’s relative abundance and percent of total fuel used were the same. The analysis then multiplied the predicted percent change in the number of fossil fuel bulk carriers by the amount of fossil fuels used by bulk carriers in 2019 to calculate the change in the amount of fossil fuels used by bulk carriers each year.

Projected change in the amount of fossil fuels used by bulk carriers. Graph produced from our analysis.

To estimate the total lifecycle emissions from bulk carriers in a year, this analysis used a multiplier that related the direct CO₂ emissions from burning fossil fuels to their upstream emissions. First, it estimated the amount of CO₂ emitted from burning a tonne of fuel, which was about 4.1 tonnes of CO₂ per tonne of fuel. Then, an International Council on Clean Transportation figure of .4311 tonnes CO₂ per tonne of fuel was used for the upstream emissions of heavy fuel oil.[9]Comer, Bryan, and Lludmilla Oslpova. 2021. “Accounting for Well-to-Wake Carbon Dioxide Equivalent Emissions in Maritime Transportation Climate Policies.” International Council on Clean … Continue reading This calculation assumed that all bulk carriers were using heavy fuel oil, which was the most commonly used type of marine fuel in 2019 and has the lowest upstream CO₂ emissions per tonne of fuel.[10]Placek, Martin. “Amount of Fuel Consumed by Ships Worldwide by Fuel Type 2020 | Statista.” n.d. Accessed November 18, 2021. … Continue reading[11]Comer, Bryan, and Lludmilla Oslpova. 2021. “Accounting for Well-to-Wake Carbon Dioxide Equivalent Emissions in Maritime Transportation Climate Policies.” International Council on Clean … Continue reading To obtain the multiplier, the tonnes of CO₂ per tonne of fuel were added together, then divided by the tonnes of CO₂ tailpipe emissions per tonne of fuel burned. This yielded the number 110%, which means that the total lifecycle emissions from bulkers are 110% of their tailpipe emissions. Each year’s estimated amount of tailpipe CO₂ emissions from bulkers was multiplied by 110% to estimate the lifecycle emissions due to bulk carriers in that year.

This analysis assumed that the methanol used by bulk carriers was green methanol, or e-methanol, produced from green hydrogen made with renewable energy and carbon from direct air capture, or DAC. Green methanol can approach carbon neutrality because, in theory, the carbon dioxide emitted during its use is the same amount as what is captured to produce it. Therefore, this analysis assumes that green methanol has zero lifecycle CO₂ emissions.

This analysis then compared the projected lifecycle CO₂ emissions from bulkers with and without green methanol adoption.

Projected CO₂ emissions from bulkers with methanol adoption (blue line) and without methanol adoption (red line). As time increases, the gap in CO2 emissions between the scenarios grows. Graph produced from our analysis.

CO2 emissions have what is known as a social cost. This means that they cause negative effects that affect not only the producer of those emissions but everyone in society. This analysis used an Environmental Protection Agency (EPA) estimate of the social cost of CO2 emissions.[12]Gallucci, Maria. “Why the Shipping Industry Is Betting Big on Ammonia – IEEE Spectrum.” n.d. Accessed November 17, 2021. … Continue reading Assuming a 3% discount rate, the social cost of carbon in 2007 US dollars was $42 per tonne for emissions in 2020, $46 per tonne for emissions in 2025, $50 per tonne for emissions in 2030, and $55 per tonne for emissions in 2030.[13]“EPA Fact Sheet: Social Cost of Carbon.” 2016. Environmental Protection Agency. https://www.epa.gov/sites/default/files/2016-12/documents/social_cost_of_carbon_fact_sheet.pdf. These figures were also used for the years in between each set of calculated years. For example, the social cost of CO2 in 2022 was said to be $42 per ton. Each year’s predicted reduction in CO2 emissions was multiplied by that year’s social cost of carbon to estimate the loss in benefit of those emissions.

Projected yearly benefit from methanol adoption in 2007 US dollars. The benefit from reducing CO2 emissions increases with time, both because the decrease in bulk carrier CO2 emissions due to methanol adoption grows with time and because the social cost of carbon increases with time. Graph produced from our analysis.

Overall, this analysis found that increasing the number of methanol ships by even a relatively small amount would have relatively large benefits. 

Limitations

This analysis did not account for the International Maritime Organization’s (IMO) Energy Efficiency Design Index standards, which sets requirements for the efficiency of new ships built starting in 2015.[14]“Energy Efficiency Measures.” n.d. Accessed November 17, 2021. https://www.imo.org/en/OurWork/Environment/Pages/Technical-and-Operational-Measures.aspx. However, this analysis showed that the impacts of these requirements on emissions from bulk carriers would be negligible, and thus these standards were not accounted for in the rest of the analysis. This analysis also did not account for the IMO’s Energy Efficiency Existing Ships Index, which aims to reduce CO2 emissions from existing ships. However, the standards are expected to have relatively little effect on CO2 emissions from shipping, and thus this analysis did not account for these standards.[15]“Potential CO2 Reductions under the Energy Efficiency Existing Ship Index | International Council on Clean Transportation.” n.d. Accessed November 18, 2021. … Continue reading Therefore, it likely overstated the emissions reduction from increasing the number of green methanol bulk carriers. 

In addition, this analysis did not account for any of the other pollutants emitted by ships and the production of their fossil fuels. For example, the Stena Germanica, a cruise ferry that was retrofitted to run on methanol, reduced its sulfur oxide emissions by 99% when it was converted to methanol fuel.[16]Balcombe, Paul, et al. “How to Decarbonise International Shipping: Options for Fuels, Technologies and Policies – ScienceDirect.” n.d. Accessed November 17, 2021. … Continue reading Sulfur oxide emissions also have social costs. For example, sulfur dioxide emissions in 2010 were estimated to have caused $42,000/ton worth of damages in 2007 US dollars.[17]Shindell, Drew. n.d. “The Social Cost of Atmospheric Release | SpringerLink.” Accessed November 20, 2021. https://link.springer.com/article/10.1007/s10584-015-1343-0. Therefore, the benefit of increasing the number of methanol bulk carriers is likely higher than what this analysis states simply because it reduces emissions of gases other than CO2.

In addition, the social cost of carbon numbers this analysis uses are from 2016. Since then, the estimated social cost of carbon has been revised multiple times. The Biden administration is currently looking to revise the estimated social cost of carbon. This revision is likely to increase the social cost of carbon.[18]Chemnick, Jean. “Cost of Carbon Pollution Pegged at $51 a Ton – Scientific American.” n.d. Accessed November 18, 2021. … Continue reading If a higher social cost of carbon were used, it would result in a higher yearly benefit from reducing CO₂ emissions than what this analysis reports.

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