JR-East Shinkansen Energy Consumption

Jiwon Lee
December 15, 2022

Submitted as coursework for PH240, Stanford University, Fall 2022

Introduction

Fig. 1: A modern Shinkansen in Japan. (Source: Wikimedia Commons)

The Shinkansen (shown in Fig. 1), also known as the bullet train, is a mode of transportation used in Japan to travel far distances across the country. This report aims to analyze the amount of energy consumed by the Shinkansen lines of JR-EAST, one of Japan's major passenger railway companies, measured in Joules per year.

Analysis

According to the JR-EAST Integrated Report 2022, JR-EAST's business operations collectively amassed 4.70 billion kWh in energy consumption in the fiscal year of 2022. [1] The breakdown is given in Table 1.

As shown in the table, the amount of energy consumed by JR-EAST's Shinkansen lines is 4.36 × 1015 J per year. We can compare this quantity to Japan's yearly total expenditure of primary energy, reported by BP to be 17.74 Exajoules ( 1.774 × 1019 J). [2] We find that the energy consumed by the operation of JR-EAST's Shinkansen lines is only a tiny fraction of the country's total energy budget:

JR-EAST Shinkansen Energy
Total Energy of Japan		 × 100% = 4.36 × 1015 J
1.774 × 1019 J		 × 100% = 0.02%
Component Energy Consumed CO2 Emitted
Offices, Buildings 0.07 billion kWh 2.52 × 1014 J 0.02 million t-CO2
Conventional Line Operation 2.51 billion kWh 9.04 × 1015 J 0.89 million t-CO2
Shinkansen Line Operation 1.21 billion kWh 4.36 × 1015 J 0.43 million t-CO2
Stations, Rolling Stock Centers 0.91 billion kWh 3.28 × 1015 J 0.32 million t-CO2
Table 1: Energy consumption breakdown of JR-EAST business operations. [1] (Converted at 1 kWh = 3.6 × 106 J)

Additionally, we can attempt to estimate the amount of energy consumed by oil-dependent transportation as another point of comparison. BP reports that Japan consumed 6.49 Exajoules (6.49 × 1018 J) worth of energy specifically from oil in 2020. [2] The U.S. Energy Information Administration reports that approximately 38% of Japan's oil is consumed by transportation. [3] Therefore, we can estimate that (6.49 × 1018 J) × 0.38 = 2.47 × 1018 Joules of energy was consumed per year by oil-dependent transportation. Once again comparing this quantity to the country's total energy budget, we can see that the fraction that oil transportation makes up is significantly higher than that of JR-EAST's Shinkansen lines:

Oil Transportation Energy of Japan
Total Energy of Japan		 × 100% = 2.47 × 1018 J
1.774 × 1019 J		 × 100% = 13.92%

With 13.92% being almost 700 times larger than 0.02%, it is reasonable to conclude that the JR Shinkansen energy budget is negligible compared to Japan's oil-related transportation energy budget as well.

Conclusion

The amount of energy consumed from operating the Shinkansen lines of JR-EAST, by far one of the most extensive railway companies in Japan, makes up only a negligible fraction of both Japan's total energy expenditure and Japan's energy expenditure from oil-dependent transportation. We can thus conclude that justifying the Shinkansen on its CO2 savings is not necessarily warranted, and that the original objective for creating the Shinkansen - to minimize energy consumed from transportation dependent on oil imports - is not necessarily achieved.

References

[1] "Integrated Report 2022," East Japan Railway Company, October 2022.

[2] "BP Statistical Review of World Energy 2022," British Petroleum, June 2022.

[3] "Country Analysis Executive Summary: Japan," U.S. Energy Information Administration, October 2020.