Technical Brief
Shore power in California: Impact on statewide grid and public health benefits
To reduce air pollution from ships, California Air Resources Board (CARB) implemented emissions control regulations for oceangoing vessels and commercial harbor craft. Shore power, which allows ships to plug into shore-based electrical power sources to operate their electrical systems while turning off their auxiliary engines, can effectively eliminate local air pollutant emissions, and has been identified as a key compliance strategy in CARB’s regulations. However, despite shore power’s role in California’s emissions control regulations and its growing adoption internationally, the magnitude of electricity demand from widespread shore power use and its implications for grid planning remain unclear.
To address this knowledge gap, this brief estimates the annual and hourly demand from shore power in California through 2050 under four scenarios, comparing these projections against statewide electricity demand forecasts. The study also quantifies air quality and health benefits from maximizing shore power use in California.
The analysis finds that shore power electricity demand would be less than 0.2% of California’s forecasted electricity deliveries in 2050 even under the maximum adoption scenario. Additionally, eliminating all at-berth auxiliary engine emissions through shore power could have avoided approximately 30 premature deaths annually in California, representing $321 million in economic benefits.
As technologies for the electrification of boiler functions mature, California could extend emissions control requirements to boilers, substantially increasing both air quality benefits and shore power infrastructure requirements. Such expansion would require coordinated planning between ports, utilities, and regulators to ensure adequate generation, transmission, and distribution capacity.