Full Report, Draft #1

1 Introduction

Singapore is ranked first in Asia, and second globally as the most sustainable city. However, Singapore accounts for 0.12% of global greenhouse gas emissions. Singapore aims to achieve 36% reduction goal in carbon emissions intensity by 2030 (Feng, 2015).

Singapore’s transportation sector contributes 15.32% to the total greenhouse gas emissions in 2016 (Feng, 2015). While usage of electric vehicle (EV) is one way to reduce greenhouse emissions, the country faces challenges to fully embrace the usage of EVs as the main means of commute. Challenges such as the high cost of EVs, Singapore’s limited EV infrastructure and the considerable safety aspects of plug-in EVs generally deter local consumers and Singapore’s public transport operators to consider the switch to EV. According to Kuttan (2017), EV drivers are afraid of travelling long distances with the risk of their vehicle batteries running flat. He added that by using the conventional EV, only the accessibility of fast chargers will encourage people to be more open to EV.

 

Today, Singapore’s buses dominantly run on diesel. With greater awareness on environmental sustainability, LTA will be buying 50 new hybrid buses which run on both electricity and diesel (CNA, 2017). When moving in electric mode, these buses emit no greenhouse gas emission or noise, thus reducing air and noise pollution. These buses, however, will run on diesel when the battery runs out and the pollution problem persists. It is thus important that public bus system converts to its electric counterparts.

 

E-buses as have zero emissions, run quieter than conventional buses, contribute less to the carbon footprint, require less maintenance, and are much cheaper in the long run, as compared to diesel buses. However, long travel distances, high turnover rate of buses in Singapore, limited charging periods, and heavy battery requirements make electric buses unsustainable in Singapore. To eliminate these problems, the usage of wireless charging technology in e-buses can be implemented.

2 Problem statement

The ideal for pure-electric buses in SG would not compromise on energy efficiency, range and infrastructure. An ideal electric bus system should be energy efficient, self-sustainable, and has good accessibility to charging points. According to Lim (2016), the K9 electric buses tested by Go-Ahead Singapore needs five to 10 hours charging time to travel 250 km, which is equivalent to six times Singapore’s longest bus route. However, the travelling distance will be reduced because of the warm and humid climate in singapore with additional battery power used for cooling. With the implementation of a wireless charging system, this will improve accessibility of charging locations around the island and reduces charging time. LTA needs to setup a pilot study to test the wireless charging system.

 

3 Purpose Statement

The purpose of this report is to outline to LTA the advantages of the wireless charging technology for electric buses which tackles the challenges in the current system, and propose to them to conduct a small-scale trial.

 

4 Proposed Solution

The solution to this problem is to use wirelessly charged electric buses. ‘Wireless charging technology’ or power transfer through magnetic induction has been tested since the early 2000s on electric buses in several countries like Italy, China, USA, Japan and Korea. Inductive charging requires a charging station which has an induction coil in it.  This then produces the electromagnetic field which transfers the energy across the gap to corresponding induction coil in the device.  The device then converts the energy from the magnetic field back into a useable electrical current which is then used to charge the battery (Thomson, 2014). These buses receive power without physical contact unlike the conventional usage of electric cables for plug-in EVs. This simplifies the charging process as busesor interchange and instead, charge on the go.

 

An example for this technology was tested by Korea Advanced Institute of Science of Technology (KAIST). This technology granted electric buses to be charged while in motion. It eliminates the need for remote static charging stations and introduces charging infrastructure embedded in the roads. As a result of charging on-the go, the company’s e-buses utilised smaller, inexpensive batteries which in turn reduced the vehicle weight. With a lighter load, the buses expanded less energy. Moreover, wireless charging plates could be built beneath the roads without having any impact on the cityscape.

4.1 Benefits of Solution

1. With the implementation of wireless charging system, it helps to simplify the charging process without the need of handling heavy charger cables and plugs.

 

1. The system basically can run 24/7 with wireless charging pads with accessibility to wireless charging pads everywhere that ensure the buses to be charged without the need of stopping. It also prevent chances of battery from running flat.

 

1. Once tested successfully on buses, this system can be a leading change in all sorts of vehicles including cars, lorries and etc. With the usage of wireless charging vehicles, this will reduce the amount of carbon emission making it more environmentally friendly.

 

1. With technology advancement, the cost of batteries will cheaper than conventional EV batteries and this will provide cheaper replacement cost.

 

1. OLEV weight of batteries will be lighter which causes the buses to use less power to move the bus and batteries will be more efficient which reduces the frequency to charge.

 

1. The need to build expensive recharge facilities can also be eliminated. This will reduce the space efficiency which can be put to other use.

 

1. This system significantly allows batteries to be smaller and reduces the amount of lithium used.

4.2 Limitations of Proposed Solution

1. Limited info from LTA on e-bus systems or trials conducted in Sg. Information that could be disclosed have already been published online. LTA representative could not disclose more information.

 

1. The exact proposed locations of charging plates on Sg roads have to be further considered and studied. Proposed locations could be the bus depots, bus stops and traffic junctions. These locations are ideal for charging e-buses, however traffic junctions necessitate the usage of the GLIDE system which detects the presence of vehicles and pedestrians at the junctions of major roads. Little is known about the effect of magnetic coupling on the GLIDE system’s wire sensors.

 

1. Bad traffic conditions might cause buses to run out of power before reaching the induction coil.

 

1. Countries that had tested out this idea are of non tropical climate but Singapore as a tropical climate country will be the first to implement this idea.

1. It is challenging to pick a suitable bus route to work well with the bus as it determines the distance of the bus stops and to obtain maximum efficiency.

 

1. It will be hard to ensure drivers do not sway while driving on the road as the induction coil will be placed at the center of the road.

 

1. With the current technology, battery prices are still expensive and bulky which might bring conflict to the project.

 

1. This idea can be implemented only if the government take this idea into consideration.

5 Methodology

5.1 Primary Research

Pending for interview with Telematics programme director.

5.2 Secondary Research

Online sources are used for the information of the different technologies available and tested in other countries and bus companies.

6 Conclusion

The implementation of wirelessly charged e-buses can be eliminated. It will, however, take time for the pilot study to be completed and evaluated before LTA decides to implement the system fully into Singapore’s roads, and observe large-scale benefits to the economy, environment and local consumers.