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Shore to Ship Power

When container ships enter ports, they dock at berth for some time in order to be unloaded and loaded. While at berth, ships turn off their main engines, which are used for propulsion while in the open ocean. Ships will turn on their smaller, auxiliary diesel engines to power certain ship operations which keep running while the ship is docked (Figure 1). 

Figure 1 : Shore to Ship power graphic. Source: Solar Impulse Foundation[1]“ABB, Shore-to-Ship Power: A State-of-the Art Electrification Solution to Make Ports More Sustainable,” Solar Impulse Foundation, June 2019, … Continue reading

These auxiliary diesel engines emit large amounts of air pollution, including greenhouse gases and particulate matter, both of which adversely affect the health of nearby residents. These pollutants increase the rates of cardiovascular and respiratory illness, disproportionately affecting people of color who tend to live closer to the industrial areas at which these emissions are prevalent.[2]Raifman, Matthew. “Quantifying the Health Impacts of Eliminating Air Pollution Emissions in the City of Boston.” IOPScience, August 20, 2020. … Continue reading The reduction in emissions from moving to shore-to-ship power at the Port of Boston specifically are calculated using the data in Table 1 below and the EPA-provided shore power emissions calculator; results are shown in Table 2. 

Vessel typeContainer ship
Vessel fuelMDO (0.1% S)[3]“Maritime Environmental Fact Sheet – Massport.” Massport, 2015. https://www.massport.com/media/2507/maritime-environmental-fact-sheet.pdf. 
Auxiliary engine size (kW)3360
Load factor0.17
Number of annual vessel calls (2020)111[4]“Conley Terminal Monthly Summary – Massachusetts Port Authority.” Massport, 2020. https://www.massport.com/media/e4ykfywb/conley-terminal-monthly-summary-dec-20.pdf.
Avg. hotel hours/vessel call (estimate)20
Transmission losses0.06
Annual energy consumption1,268,064
Table 1: Calculation Assumptions. Source: EPA Calculator and Conley Terminal Data [5]OAR US EPA, “Shore Power Technology Assessment at U.S. Ports,” Reports and Assessments, March 20, 2017, https://www.epa.gov/ports-initiative/shore-power-technology-assessment-us-ports.
NOxSOxPM10PM2.5CO2CO
Vessel emissions (MT)17.630.510.320.29874.961.39
Shore power emissions (MT)0.280.1400348.050
Damage cost to UK (euros/tonne)63851302677511[6]Department for Environment, Food & Rural Affairs. “Assess the Impact of Air Quality.” GOV.UK, March 26, 2021. https://www.gov.uk/government/publications/assess-the-impact-of-air-quality.73403[7]“Air Quality Appraisal: Impact Pathways Approach.” GOV.UK. March 26, 2021, … Continue readingN/AN/A
Health/environmental benefit to South Boston (millions USD per year)57.32.4911.611.0N/AN/A
Table 2: Public health benefit in Boston due to switching Conley Terminal to shore-to-ship power. Source: EPA Calculator [8]OAR US EPA, “Shore Power Technology Assessment at U.S. Ports,” Reports and Assessments, March 20, 2017, https://www.epa.gov/ports-initiative/shore-power-technology-assessment-us-ports.

If container ships move to shore-to-ship power over continuing to use their auxiliary diesel engines, nitrogen oxide (NOx) emissions can be reduced by up to 98%, sulfur oxide (SOx) by up to 72%, and CO2 by up to 60%. Particulate matter emissions and carbon monoxide emissions are practically eliminated, as they are negligible for ships connected to shoreside energy.[9]Tanman, Arman. “Shore Power Technology Assessment at US Ports.” Environmental Protection Agency, March 2017. https://www.epa.gov/ports-initiative/shore-power-technology-assessment-us-ports. In one year, the public health benefit conferred to South Boston—the neighborhood surrounding the Port of Boston, and most directly affected by its emissions—from reductions in NOx, SOx, and particulate matter emissions sum to $82.4 million, as seen in Table 2. [10]OAR US EPA, “Shore Power Technology Assessment at U.S. Ports,” Reports and Assessments, March 20, 2017, https://www.epa.gov/ports-initiative/shore-power-technology-assessment-us-ports. This takes into account not only the decreased mortality rates from cardiovascular and respiratory illnesses, but also decreased incidence of hospital visits and increased worker productivity due to decreased time off for illness. The damage cost also factors in the impact of emissions on the ecosystem and damage caused by ozone (a byproduct of NOx) and SOx to materials.[11]“Air Quality Appraisal: Impact Pathways Approach.” GOV.UK. Accessed November 20, 2021. … Continue reading

However, the up front infrastructure costs for this are high. Both ports and ships must be retrofitted to supply and receive electricity. According to estimates made by the Massachusetts Port Authority in 2016, the capital cost of installing the appropriate electrical infrastructure for one berth is about $10 million; the cost to retrofit one ship to receive shore-to-ship power is about $1 million.[12]“Massport Shore-to-Ship Power Study.” Boston: Massachusetts Port Authority, August 5, 2015. Operational costs are also high for the port, as peak power demand for a container ship reaches about 3.36 MW, enough to power one entire terminal of the Logan International Airport.[13]“Massport Shore-to-Ship Power Study.” Boston: Massachusetts Port Authority, August 5, 2015.  Ports would need to improve their grid infrastructure in order to sustain this power demand. However, at low-traffic times increased power capacity would go unused, and ports must still pay for this unused capacity throughout the year. For Conley Terminal specifically, which services container ships for the Port of Boston, retrofitting all vessels, installing electrical infrastructure on berths, and upgrading the electrical grid would demand an upfront cost of $85 million.[14]“Massport Shore-to-Ship Power Study.” Boston: Massachusetts Port Authority, August 5, 2015. 

Considering the immense benefit conferred upon the port’s surrounding ecosystem and neighborhood as a result of switching to shore-to-ship power, however, it is well worth encouraging large ports to switch to shore-to-ship power. Those ports for whom upgrading grid infrastructure is desired and which consistently have high traffic volumes are especially good candidates for implementation of this policy, since the disadvantages are negligible for them. 

Federal or state grants should be provided to ports in order to subsidize the necessary upgrades and to prevent the increased electricity cost from falling on the shoulders of residents living near the port. If regional regulations are implemented, then upgrading will not make ports less competitive compared to regional neighbors, so they will be less reluctant to do so. When the California Air Resources Board mandated reduced at-port emissions in 2007, federal and state grants were provided to ports to assist with upgrading to shore-to-ship power.[15]“Massport Shore-to-Ship Power Study.” Boston: Massachusetts Port Authority, August 5, 2015.  Implementing upgrades gradually also helps to ease the financial burden on the port; for instance, the Port of San Diego initially only implemented infrastructure capable of powering one ship at the time, leaving flexibility for future upgrades.[16]“Port Planning and Investment Toolkit: Appendices.” American Association of Port Authorities. US Department of Transportation Maritime Administration, 2016. … Continue reading 

Despite the challenges associated with implementing shore-to-ship power, it is a promising solution to the problem of at-berth emissions, especially if ports receive federal and/or state financial assistance. Emissions from ships idling at ports can be essentially eliminated through this solution, improving quality of life for surrounding communities and benefiting the environment.

Shore to Ship Power Timeline

  • 2025: pass legislation (either in all US states with significant maritime trade or at the US federal level) that require the implementation of shore to ship power in large ports by 2040, and encourage ports to construct shore power facilities. Subsidize upgrading power grid.
    • California passed the legislation to implement shore to ship power in 2007 with the goals of 50% by 2014, 70% by 2017, and 90% by 2020.[17]“Massport Shore-to-Ship Power Study.” Boston: Massachusetts Port Authority, August 5, 2015. With this information, we will use a timescale of 15 years to match that implemented in California.
    • The port of San Diego completed the design, planning, and construction of shore power in under three years with federal and state grants (2017-2020).[18]“Port Planning and Investment Toolkit: Appendices.” American Association of Port Authorities. US Department of Transportation Maritime Administration, 2016. … Continue reading The current equipment allows for one cruise vessel to connect to shore power, and the current expansion aims to construct shore power that will allow two vessels to connect to power by September 2022.[19]Page, Brianne Mundy. “Port of San Diego to Double Shore Power at Cruise Terminals.” Port of San Diego Environment, April 26, 2021. … Continue reading Assuming that ports with electric grids that are feasible for shore power will be able to implement shore power for one vessel in three to five years, 15 years is a reasonable timeline for implementation of shore power.
    • Since shore to ship power is currently most feasible in large ports with a robust electric grid, and would take around $7-10 million to construct for one berth, the legislation will only require large ports to implement shore to ship power.[20]U.S. Department of Transportation Maritime Administration. “Appendices” In Port Planning and Investment Toolkit, … Continue reading[21]Massachusetts Port Authority. “Massport Shore-to-Ship Power Study,” August 5, 2016. www.web.archive.org/web/20161220223358/http://www.massport.com/media/403886/Massport-Report-Shore-Power.pdf
  • 2040 onwards: shore to ship power implemented everywhere it is required. Only big ports will implement shore to ship power.

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