Application of sustainable energy technology (solar) to electric transportation

Written by Dr. Arshad Salema, Senior Lecturer, School of Engineering

Malaysian transportation sector consumes about 40% of the total energy demand in the country that generates about 70 million metric tons of carbon dioxide (CO2) per year. Out of which 85 per cent of this carbon emissions comes from road transport. To change this, electric buses which run exclusively on electric batteries, were employed to align with sustainable transport system that can reduce the carbon emissions. Even though these battery electric buses are clean on the road and do not create pollution, but the battery needs to be charged regularly to operate these buses.

However, the Malaysian electricity grid is highly dependent on fossil fuel (coal and natural gas) with very small percentage of renewable energy mix. It means that indirectly the electric buses are contributing to carbon emissions. Moreover, charging the buses induces the maximum demand (MD) i.e. spike in electricity consumption that comes with increase in operation cost of the bus depot. So, the specific problems are:

i) electric buses consumes high amount of electricity to charge (that cause high MD),
ii) increases the operation cost of bus depot, and,
iii) ultimately it can indirectly contribute to the carbon emissions.

Electric buses charged using the grid are still not totally sustainable and therefore the aim of our research work was to apply solar energy to reduce the dependency of electric buses operation on gird that can also reduce both electricity consumption and carbon emissions in long run. Thus, by this way we can develop sustainable transport solution for the electric bus transport system in Malaysia using solar energy. The project will showcase a viable solution to develop an integrated low-carbon township in Bandar Sunway. We are closely working with Prasarana Bhd. and RapidBus. The project can be expanded to other bus depots and transport system in Malaysia.

The major outcome of the project is that solar energy is technically feasible and economically viable for electric bus depot. Under the Net Energy Metering (NEM) scheme, the electric bus depot can save about RM 15,000 (depends on the conditions) monthly on the electricity bill, with a pay back period of about 7 years and can avoid nearly 12,000 tonnes of CO2 over life time of solar system. At present we are in discussion with Prasarana Bhd. and Sunway Engineering Company for the implementation of the project.

The project is in direct line with the SDGs no. 7 (affordable and clean energy), 11 (sustainable cities and communities), and 12 (responsible consumption and production) that can impact both global and local society by reducing the carbon emissions and operation cost of the electric bus depot.