What are the Power Supply Methods for Rubber-Tyred Gantry (RTG) Cranes?

1. Diesel Generator Set Power Supply (Traditional RTG)

Operating Principle: Features an onboard diesel engine that drives a generator to provide power for the entire machine.
Key Features
✅ Highest Mobility: Requires no external power connection, allowing for operations in any area of ​​the container yard with flexible dispatching capabilities.
❌ High Operating Costs: Subject to volatile diesel prices and high fuel consumption; annual fuel costs for a single unit can reach hundreds of thousands of RMB.
❌ Poor Environmental Performance: Generates significant exhaust emissions (NOx, particulate matter) and noise pollution, failing to meet low-carbon requirements.
❌ Cumbersome Maintenance: Involves numerous moving parts—such as the engine and transmission—resulting in high costs for periodic maintenance.
Applicable Scenarios: Older container yards, temporary operation sites, and environments with low environmental protection requirements.
2. Ground-Level Conductor Rail Power Supply (e-RTG / Electric RTG)
Operating Principle: Draws power from the electrical grid via ground-laid conductor rails, supplying electricity to the equipment through a current collector; some models retain a small-capacity battery to facilitate short-distance transfers between zones.
Key Features
✅ Low Operating Costs: Replaces diesel with electricity; electricity prices are stable, and energy consumption costs are only 30%–50% of those for diesel-powered models.
✅ Zero-Emission & Eco-Friendly: Produces no exhaust emissions and minimal noise, meeting the requirements for low-carbon upgrades in ports.
❌ Limited Mobility: The operating range is restricted by the layout of the conductor rails; transfers between container zones require reliance on auxiliary equipment or the onboard short-range battery.
❌ High Infrastructure Costs: Requires the installation of infrastructure such as conductor rails and cable trenches, entailing significant upfront investment.
Applicable Scenarios: Operations within fixed container zones, large-scale container ports, and regions with strict environmental protection regulations. 3. Lithium Battery / Supercapacitor Power Supply (Pure Electric RTG)
**Power Supply Principle:** Equipped with high-capacity lithium batteries or supercapacitor banks, the equipment is powered through charging (via battery swapping or fast charging).
**Key Features**
✅ **Zero Emissions + High Mobility:** Produces no exhaust pollution and is free from the constraints of conductor rails, allowing for unrestricted dispatching across the entire yard.
✅ **Low Energy Costs:** Electricity costs are comparable to conductor-rail models, and charging can be scheduled during off-peak hours to take advantage of lower electricity rates.
❌ **High Battery Costs:** Lithium batteries have a lifespan of approximately 5–8 years, resulting in high replacement costs; supercapacitors offer high power density but low energy density, leading to a limited operating range.
❌ **Charging Dependency:** Requires supporting infrastructure (fast-charging stations or battery-swapping stations); operational efficiency is subject to charging times.
**Applicable Scenarios:** Newly constructed "green ports," automated container yards, and scenarios where both high mobility and environmental sustainability are critical requirements.
4. Hybrid Power Supply (Hybrid RTG)
**Power Supply Principle:** A combination of a diesel engine and a battery/supercapacitor system; the diesel engine charges the battery, while the battery assists in providing peak power output or powers the equipment during engine idling/shutdown periods.
**Key Features**
✅ **Reduced Fuel Consumption:** Compared to pure diesel models, fuel consumption can be reduced by 20%–40%, thereby lowering exhaust emissions.
✅ **Retained Mobility:** Requires no external power connection, allowing for operations across the entire yard with flexible dispatching capabilities.
✅ **Transition-Friendly:** Requires no large-scale infrastructure modifications, serving as a practical compromise solution for ports transitioning from traditional diesel RTGs to electrified operations.
❌ **System Complexity:** Involves the integration of two distinct power systems, resulting in complex control logic and slightly higher maintenance difficulty compared to pure diesel models.
**Applicable Scenarios:** Retrofitting of existing diesel RTGs, and ports with limited budgets seeking to reduce fuel consumption. 
💡 Selection Recommendations
If prioritizing maximum flexibility with low environmental requirements: Choose Diesel RTG.
If prioritizing low costs + zero emissions within a fixed container block: Choose Conductor Rail e-RTG.
If prioritizing zero emissions + full-yard mobility with a sufficient budget: Choose Li-ion / Supercapacitor RTG.
If aiming to reduce fuel consumption without major infrastructure modifications: Choose Hybrid RTG (or retrofit existing Diesel RTGs into hybrids).