By using the hoist motors as generators when lowering containers the energy produced is stored until it’s needed. Similarly, under braking or decelerating conditions, energy can be produced from the electric drive system and stored.
The machine’s supercapacitor energy storage system draws on the saved energy before making further demands on the diesel engine for movement or lifting, thereby drastically reducing fuel consumption and emissions.
An in-cab display shows the machine’s energy flow, thus the driving style can be further fine-tuned to make the most efficient use of the straddle carrier.
The Pro Future hybrid technology package includes a Variable Speed Generator (VSG) diesel-generator package with temperature-controlled fan technology that optimises engine use by determining whether high or low engine power is needed, further reducing both energy consumption and pollution.
“The cyclical operation of straddle carriers in container terminals is the foundation upon why hybrid technology produces such good results,” said Ilkka Annala, vice president of Kamar’s straddle carrier product line. “This type of operation is very transient and has suitable positive and negative energy peaks that can be utilised to save fuel.”
“Genuine reductions in energy use also mean genuine environmental protection, as the emissions of harmful greenhouse gases, such as CO2, are reduced considerably. On an annual basis, more than 50 tonnes of CO2 emissions per straddle carrier can be eliminated while employing hybrid technology.”
The company says there is a possibility of applying various stages of the Pro Future hybrid technology package to future ESC W models.