Electric vehicles in Singapore
(Photo credit: Mitsubishi)
Electric vehicles (EVs) offer great potential for reducing energy consumption and emissions in the transport sector. Instead of a fuel tank and an internal combustion engine (ICE), EVs are propelled by an electric motor powered by a battery that is charged from the grid. An electric powertrain uses less energy to propel a vehicle due to fewer moving parts and fewer points of friction. For this same reason, an electric powertrain may reduce many maintenance costs. Instead of having an engine, lubrication system and a transmission that has losses due to friction, an EV has a battery that powers a motor.EVs can also have regenerative braking that captures kinetic energy from braking to recharge the battery; this further increases energy efficiency. Charged from the grid, the battery obviates the need for petrol and can be recharged from a conventional electrical outlet.
Rapid charging infrastructures
Furthermore, high-voltage rapid charging systems are deployed in Singapore (as well as other cities) to supplement the regular electric grid and to provide charging times of less than an hour. Charging at a standard 220V outlet can take over 6 hours. To achieve a reasonable driving range, the battery is higher capacity than a conventional vehicle's and utilises newer technology than that of a lead acid battery used in a conventional vehicle. This significantly increases the price of the battery and drives the cost of an EV higher than that of a comparable petrol vehicle.
Green Vehicle Rebate
The limited driving range of EVs relative to ICE vehicles and the longer time needed to recharge an EV's battery (compared with the time required to refuel a conventional vehicle) remain impediments to broader EV adoption by the public. To help offset the price premium of EVs in Singapore, electric vehicles are eligible for the Green Vehicle Rebate, which is equivalent to 40 percent of the vehicle purchase price.
An electric vehicle test-bed for urban living
The Singaporean government has put together a multi-agency EV Task Force (EVTF) to investigate the pros and cons of this technology via vehicle test-bedding. The test-bed is headed by the city-state's Energy Market Authority and Land Transport Authority. In this test-bed (discussed elsewhere on the SIEW Web site), corporate and government fleets will purchase and operate various electric vehicles for use in their day-to-day operations. The Energy Studies Institute at the National University of Singapore will conduct technical and economic analysis of these vehicles' performance and characterise Singaporeans' knowledge and perception of EV technology. The goal of the test-bed is to determine the suitability of EVs in Singapore and to quantify their benefits.
There are many characteristics that distinguish Singapore from other cities testing or deploying this new vehicle technology. Singapore is a dense, urbanised city-state and driving distances are shorter than in more suburban locales. This fits well with the limited driving range of EVs and allows for convenient siting of EV infrastructure such as charging stations.
Singapore's electric grid is the most reliable in the region and is fuelled largely by natural gas. Gas has lower emissions intensity than other base-load fossil fuel energy sources, as well as petrol used to fuel conventional vehicles. This results in lower greenhouse gas emissions and means that EVs are less detrimental to air quality relative to comparable ICE vehicles, even when accounting for electricity generation.
Certificate of Entitlements
Also, Singapore has unique transport policies designed to limit the vehicle population and its consequences: Traffic congestion and pollution. For example, one must purchase a Certificate of Entitlement (COE, currently over S$ 50,000 for 10 years) and also pay an Additional Registration Fee (ARF, 100 percent of the vehicle price) to purchase a vehicle.
These extra expenses, in addition to other increased costs, significantly change the economics of owning a vehicle. These higher ownership costs, coupled with an extensive and efficient public transport system, have resulted in very low rates of vehicle ownership and a relatively modern vehicle population.
Because EVs command a price premium over conventional vehicles, the ARF multiplies the premium. A principle challenge is to reduce energy consumption in the transport sector without promoting greater vehicle adoption, "green" technology-driven or otherwise.
Electricity cheaper than fuel
Operationally, energy (electricity) costs for an EV are much lower than fuel costs for a comparable ICE vehicle due to electricity costs being cheaper than petrol per unit of energy and lower energy consumption by EVs. However, this savings will not offset the higher upfront costs of EVs over the 10-year COE period.
For example, an electric Mitsubishi i-MiEV will have 17 percent lower energy consumption than its petrol variant Mitsubishi i based on average Singaporean driving patterns and manufacturer specifications. Due to the difference in electricity and petrol costs, the energy costs of the i-MiEV are one-third those of the petrol Mitsubishi i. The Mitsubishi i-MiEV is one of the electric vehicles being evaluated as part of the test-bed in Singapore.
The lower energy consumption and use of natural gas in generating electricity results in lower damage costs from various pollutant emissions, including criteria pollutants that reduce air quality and greenhouse gases. Using the same vehicle comparison, the i-MiEV reduces annual emissions of all pollutants considered in Singapore (criteria pollutants and greenhouse gases) when the electricity grid is fuelled by natural gas relative to the Mitsubishi i.
Valley filling and peak shaving
Other than energy usage and emissions reductions, EVs can offer benefits to electricity grid operators. Charging EVs at night will result in "valley filling"--creating demand for electricity when it is otherwise low and reducing the gap in peak base-load demand and off-peak demand. EVs can potentially provide regulation services to utilities to help keep electric voltage and frequency stable. Applications using EVs as an energy buffer have the potential to accommodate integration of intermittent renewable energy sources into the electric grid.
This sort of vehicle-to-grid technology is not yet commercially available, but EVs can assist in load balancing in the future by providing excess energy stored in their batteries back to the grid when electricity demand is highest (peak shaving). Providing energy from a vehicle's battery back to the grid would exacerbate consumers' range anxiety issues, however, and the added stress on the batteries due to additional charging and discharging is still unknown.
The potential of EVs
Although there has been much hype surrounding the potential of electric vehicles. They must undergo further technical advancements to allay consumer reservations and be cost competitive with more mature ICE vehicles. Specifically, the manufacturing costs of batteries need to decrease significantly to make EVs cost competitive with conventional vehicles. Furthermore, advances in battery capacity and durability need to occur to allay potential consumers' range anxiety.
The EV test-bed seeks to quantify the pros and cons of this disruptive technology to help guide the discussion regarding the suitability of these vehicles in Singapore.
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