Last updated on March 10, 2026
Where shore power works, where it falls short, and how emissions capture and control serves as an alternative for immediate emissions reductions.
Shore power, also known as cold ironing, allows vessels to connect to land-based electricity while docked at berth, instead of running onboard auxiliary diesel engines. Also known as cold ironing or onshore power supply (OPS), shore power reduces emissions of particulate matter (PM), nitrogen oxides (NOx), sulfur oxides (SOx), greenhouse gases, and noise pollution at port.
Shore power has become a cornerstone of port emissions reduction strategies, with the market expected to expand from roughly $1.6 billion today to $2.3 billion by 2030.
But despite its value, shore power remains limited. Today, only roughly 3% of ports have the infrastructure required, and many vessels still cannot use it due to compatibility issues, retrofit costs, or grid constraints.
The reality is clear: shore power is essential, but not sufficient on its own. Ports and operators need complementary emissions reduction solutions that can reduce pollution immediately, across diverse vessel types, while long-term electrification continues. Mobile emissions capture and control systems offer one such path.
Why shore power is expanding — and where it works best
Shore power has become a leading emissions reduction strategy because it’s an infrastructure-driven solution that aligns with global public health and environmental commitments. When available and compatible, shore power can significantly reduce at-berth emissions and cut noise pollution for surrounding communities and waterfronts.
For policymakers, shore power also offers something visible: a clear signal of climate ambition and a concrete step toward long-term port electrification. As a result, it is increasingly reinforced through international policy:
- California (CARB): The At-Berth Regulation requires container, reefer, and cruise vessels to plug in or use equivalent emissions control systems.
- Europe (FuelEU Maritime): Mandates shore power for large container and passenger ships at major EU ports by 2030.
- China: Enforces shore power requirements as part of its Marine Environmental Protection Law.
- South Korea, Japan, Canada: Expanding shore power deployment through subsidy programs and pilot projects.
But policy pressure alone doesn’t make shore power universally viable. It works best for ships with long dwell times (to support connection and disconnection), predictable schedules, and modern onboard electrical systems—typically found on newer or larger vessels.
As a result, adoption has concentrated in a narrow set of vessel classes such as cruise ships, ferries, and major container lines. The cruise sector, in particular, is moving quickly: 72% of vessels from the industry’s leading trade organization are expected to be shore power capable by 2028. Shore power fits best in regions with the resources and vessel profiles to support it.
The limits of shore power
Shore power delivers real emissions benefits where it can be deployed, but its limitations are significant—and they prevent most ports and vessels from using it today. Technical, economic, and grid-related barriers make large-scale adoption unrealistic in the near to medium term, even in regions with strong regulatory pressure.
Vessel readiness and compatibility
One of the biggest bottlenecks lies on the vessel side. As of May 2024, only about 2.4% of the global commercial fleet was equipped with shore power connections, underscoring how limited ship-level readiness truly is. Several issues contribute:
- Lack of global standards: Variations in voltage, frequency, and connection types make interoperability difficult. A ship equipped for one port may not be compatible with another.
- Maintenance and safety demands: High-voltage equipment near water requires rigorous safety systems and continuous maintenance.
- Vessel lifecycle considerations: Older vessels nearing retirement often cannot justify the multimillion-dollar retrofits required.
High costs and economic barriers
Shore power requires major investment on both the vessel and port sides, and the economics often don’t align with operational realities.
- Vessel costs: Retrofit expenses typically start around $1 million per vessel. And for older vessels, the return on investment may never materialize.
- Port infrastructure: New substations, switchgear, transformers, trenching, and cabling can immensely drive up project costs.
- Operational costs: In some markets, electricity can be more expensive than marine fuel. Staffing, inspections, and ongoing maintenance add further expense.
Grid constraints and energy supply limitations
Even in regions with strong regulatory and financial support, the local grid may not be available. Large vessels draw enormous amounts of power: a large container ship, with refrigerated containers, may require about 1,450 kW of power. Key challenges include:
- Limited grid headroom: Many ports sit in dense urban or industrial areas where grid headroom is already limited. Seasonal demand spikes and local consumption pressure can further reduce availability.
- Slow, costly upgrades: Grid expansions require complex permitting, multi-year construction timelines, and significant investment—often beyond what ports or utilities can support.
- Grid reliability concerns: Power outages or instability can interrupt operations and force vessels back to onboard generators, undermining emissions goals.
- Upstream emissions: Shore power is only as clean as the grid supplying it. In regions still reliant on fossil fuels, this solution may simply shift emissions upstream rather than eliminate them.
- Boiler emissions: Critically, shore power does not address emissions from boilers used for steam and heating, which remain a significant source of PM and NOx.
Emissions capture and control: A faster, scalable path to cleaner ports
Given these constraints, ports are increasingly pursuing complementary solutions that can deliver immediate emissions reductions while long-term electrification continues. Mobile emissions capture and control systems, like STAX, offer a practical, scalable alternative that works across vessel types without requiring retrofits or grid investments.
These systems capture pollutants directly from vessel exhaust, including PM, NOx, SOx, and other harmful emissions. They operate independently of a vessel’s configuration, schedule, or age. Key advantages include:
- Lower upfront investment: No need for substations or large-scale electrical upgrades.
- Rapid deployment: Installations can be completed in weeks, not years, allowing ports to reduce emissions immediately.
- Universal vessel compatibility: Works across all ship types, including older vessels unlikely to ever adopt shore power.
- Operational resilience: Keeps ports compliant during grid outages or unexpected downtime. For example, the Port of Hueneme deployed STAX to mitigate the impacts of the damage incurred to the port’s shoreside power system.
- Comprehensive impact: Captures boiler emissions that shore power cannot. Compared to shore power, systems like STAX can capture 12% more pollution on containerships and 4% more on ro-ro vessels.
For ports seeking real progress on emissions, combining shore power with emissions capture and control technologies offers the most practical, scalable path to cleaner operations and regulatory compliance.
Learn more about STAX’s technology, and how emissions capture and control can support your port’s compliance roadmap.
Frequently Asked Questions About Shore Power
What is shore power for ships?
Shore power allows ships to plug into land-based electricity while at berth instead of running auxiliary engines. This reduces emissions of particulate matter (PM), nitrogen oxides (NOx), sulfur oxides (SOx), greenhouse gases, and noise. Shore power is most effective for vessels with compatible electrical systems and predictable schedules, including many cruise ships and large container ships.
What are the pros and cons of shore power for ports?
Pros:
- Significant reductions in at-berth emissions and noise
- Supports regulatory compliance and climate targets
- Advances long-term port electrification strategies
Cons:
- Limited global availability (~3% of ports)
- High costs for vessel retrofits and port infrastructure
- Compatibility issues with older or diverse fleets
- Dependence on local grid capacity and reliability
- Does not eliminate boiler emissions
Are there alternatives to shore power?
Yes. Ports can reduce emissions without shore power or in addition to shore power through mobile emissions capture and control systems like STAX that remove pollutants directly from vessel exhaust at berth. These systems operate independently of grid capacity and do not require vessel retrofits, making them suitable for older or diverse fleets.
Other options include alternative marine fuels, onboard exhaust treatment systems such as scrubbers, and operational measures like speed optimization. However, these approaches often require vessel modifications, new fuel infrastructure, or long transition timelines, which can limit their near-term impact.
For many ports, a hybrid strategy combining shore power with emissions capture technologies provides the most scalable and immediate emissions reduction pathway.
What solutions exist for older vessels that can’t use shore power?
Older vessels that cannot use shore power due to cost, technical limitations, or remaining service life still have options.
Emissions capture and control systems like STAX provide a practical alternative to shore power by connecting directly to a ship’s exhaust at berth and removing PM, NOx, SOx, and other pollutants. Because these systems do not require onboard modifications or grid access, they allow ports to reduce emissions from older vessels immediately and maintain compliance with air quality regulations.
