The new environmental regulations present container terminals with the challenge of reducing their carbon footprint, while maximizing their return on investment.   To address such a challenge, the hybrid system has become the standard solution. The typical hybrid system consists of a battery (lithium iron phosphate type), a battery charge-discharge control system and a BMS (battery management system).
Those components work together with a lower HP diesel-genset. During the RTG normal operation, the battery supplies the system, while the engine will be kept off. When the threshold of 30%-35% of battery charge is reached, the charging cycle starts, using the diesel engine as the power supply. The system also converts potential energy into electric stored energy, during hoist down cycles. The stored energy is then used during the hoist up cycles, thus reducing the fuel consumption. 
Below, some advantages of a hybrid system:
◆Flexible operation 
◆Potential energy is not wasted. It is converted into electric energy and used to reduce fuel consumption.
◆Energy (fuel) saving of at least 50%-60%.
◆Lower carbon emissions
◆Battery lifetime: 8 years

◆Downsizing of the diesel engine

CASE: RTG hybrid system retrofit;