Hybrid buses for Seoul

Han-Young Choi, President of Hyundai Motor´s Commercial Vehicle Division, signed the agreement on June 9 at City Hall with Se-hoon Oh, the Seoul Mayor, to supply the city with 7,748 eco-friendly buses by 2018.

By securing the sale, Hyundai Motor will now be able to actively invest in the development and commercialization of low-polluting technology. Hyundai will begin supplying the city with mild-hybrid buses this year, then supply full-hybrid system buses from 2011 and fuel-cell electric buses ?which have zero pollution– starting from 2013.

A bus with a mild–hybrid system is one where the hybrid system is only partially applied. It works the same way as a full–hybrid system in that its engine automatically shuts off when the bus comes to a full stop, cutting back on the use of fuel. However, the mild system is just one–fifth the cost of a full–hybrid system.

The biggest difference between a mild–hybrid system and a full–hybrid system is that when a full–hybrid system comes to a stop, it transforms the heat created from the brakes into electricity and uses it as kinetic energy when accelerating. A mild–hybrid system uses this energy in its motor to cool the engine.

Furthermore, a mild-hybrid system bus has a 10-15 percent better fuel efficiency than a conventionally powered diesel or CNG (Compressed Natural Gas) bus. It also contributes to cleaner air by cutting CO©üemissions by 21 percent and nitrogen oxide emissions by 89 percent, compared with a diesel bus.

Hyundai Motor on Monday delivered two mild–hybrid system buses to an operator through the Seoul Metropolitan Government, and will handover 12 more by the end of this month.

Hyundai Motor completed the development of its mild–hybrid system, which is the company´s proprietary technology, in April. Since then, the buses have been undergoing fleet test operations with a number of local bus companies.

Credits: Jarvis