Shore power, also known as cold ironing or Alternative Marine Power (AMP), is a technology that enables ships to turn off their diesel-fueled auxiliary engines while docked at a port and connect instead to the land-side electrical grid. Traditionally, ships must keep their auxiliary engines running to power essential onboard services, such as lighting, refrigeration, cooling, heating, and communications (known as the “hotel load”).
How Shore Power Works
- Connection: When a shore power-equipped ship berths, heavy cables are connected from the port’s power supply station to a dedicated connection point on the vessel.
- Conversion: The land-side power grid often has different voltage and frequency requirements (e.g., $50 \text{ Hz}$) than the ship’s systems (e.g., $60 \text{ Hz}$). The port must use specialized equipment, such as frequency converters, to match the shore power to the ship’s electrical system.
- Transfer: The ship’s crew performs a seamless transition process, gradually transferring the “hotel load” from the auxiliary engines to the shore power supply. This process allows the auxiliary engines to be completely shut down, or “cold ironed.”
Environmental Benefits
The primary driver for implementing shore power is the significant environmental improvement it provides, particularly in port cities:
- Air Quality: Shore power drastically reduces local air pollution by eliminating the combustion emissions from diesel engines at the berth. This reduces the release of harmful pollutants like Nitrogen Oxides , Sulfur Oxides, and particulate matter (PM) by up to 98%, directly improving air quality for nearby communities.
- Noise Reduction: Shutting down the powerful auxiliary engines substantially reduces noise and vibration in the port area, benefiting both port workers and residents.
- Climate Change: If the shore power is supplied by a clean or renewable energy source (like hydro or wind), it leads to a significant reduction in overall Greenhouse Gas emissions.
While the initial capital investment for both ports and ships is substantial, regulatory mandates (like the EU’s Fit for 55 and long-term operating cost savings are accelerating its global adoption.
