Technical 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 EVinfrastructure 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.
- 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.
- 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.
- With technology advancement, the cost of
batteries will cheaper than conventional EV batteries and this will provide
cheaper replacement cost.
- 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.
- The need to build expensive recharge
facilities can also be eliminated. This will reduce the space efficiency
which can be put to other use.
- 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.
2.
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.
3.
Bad traffic conditions might cause buses to run out of
power before reaching the induction coil.
4.
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.
5.
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.
6.
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.
7.
With the current technology, battery prices are still
expensive and bulky which might bring conflict to the project.
8.
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 can implementing the system fully into Singapore’s
roads, and observing large-scale benefits to the economy, environment and local
consumers.
References
Fischer, M., (2016). Scandinavia’s first electric bus
with wireless fast charging. Retrieved from https://news.vattenfall.com/en/article/scandinavia-s-first-electric-bus-wireless-fast-charging
Lim, A., (2016, 6 August). E-bus to
ply public route in trail lasting six months. The Straits Times.
Retrieved from http://www.straitstimes.com/singapore/e-bus-to-ply-public-route-in-trial-lasting-six-months
National Environment Agency, (2016). Singapore second
biennial update report 2016. Retrieved from http://www.nea.gov.sg/docs/default-source/energy-waste/climate-change/second-biennial-update-report-(16-dec-2016).pdf
One Motoring, (n.d.). Green Link
Determining (GLIDE) System. Retrieved March 08, 2018, from https://www.onemotoring.com.sg/content/onemotoring/en/on_the_roads/traffic_management/intelligent_transport_systems/glide.print.html
Suh, N. P., Cho, D. H., Rim, C. T., (n.d.). Design of On-Line Electric Vehicle (OLEV) [Conference proceeding].Retrieved from www.springer.com/cda/content/document/cda_downloaddocument/9783642159725-c1.pdf?SG
Thomson, K., (2015). Problems with Wireless Charging.
Retrieved from https://cambrionix.com/blog/problems-with-wireless-charging/
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