The world is changing, with lots of news in terms of vehicles, components, technology and infrastructure. We are creating conditions for cleaner and more sustainable urban mobility. The numbers are still low, but they show a new trend that I consider irreversible. I am sure that in the future it will be adopting a hybrid bus using the advanced biofuel HVO, as I explain below.
Last year, at an event on urban mobility in Brazil, a hybrid bus model was launched, aimed at sustainable public transport, with 100% of local technology. The vehicle has an electric motor and is powered by two energy sources – battery bank and diesel or biofuel generator set – which can operate together or independently.
How does the hybrid bus work?
It is important to understand that the operation of a hybrid bus is similar to that of a trolleybus – a vehicle powered by electric electricity through cables. The main difference is that the departure is made using a diesel engine, then the bus uses the electric motor to continue a journey.
In this case, to complement the process of sustainable efficiency, we must use the renewable diesel oil HVO (vegetable oil treated with hydrogen). It is an advanced “immediate delivery” biofuel that goes “straight to the tank” and completely replaces fossil diesel – perfect for the hybrid bus. The main advantage of HVO over fossil diesel fuel is that it pollutes less, preventing disease and saving lives in cities.
In electric mode, the bus’s engine-generator is turned off and the vehicle runs on battery power only. The shutdown can be triggered by the driver or by a GPS sensor on the public road, for example, when the vehicle enters a Zero Emission Zone.
During operation, the batteries are continuously recharged by regenerative braking technology (KERS), and may also have the contribution of the motor-generator. Switching modes can be repeated several times, depending on the operation profile. In hybrid mode, the motor-generator works in constant rotation (stationary), in the best efficiency curve for minimum consumption and emissions.
Hybrid in the world
The world’s first hybrid double-decker bus entered service on route 141 in London, England, in 2007. Currently, one of the places with the highest incidence of such vehicles in public transport is China. After being recognized as one of the most polluting territories in the world, the country has become a leader in hybrid technology, as a way of reducing the pollution emitted. The use of the hybrid bus in Brazil started in 2010, in the city of São Paulo.