The Environment Impact of Electric Vehicles - Essay Example

?Assessment of the Environment Impact of Electric Vehicles 541791) Introduction With the increase in consumption of fossil fuels it is but inevitable that this would get depleted in the times to come. Alternate sources of energy that can fuel cars and other vehicles are always on the forefront of innovations. New Hybrid cars have emerged in the market along with the electric cars which run on electricity. (Markel Tony, 2007) These are now also being patronised by traditional car companies that over the years have been designing cars having internal combustion engines. Source: Shim et al, 2009, Electric car-Tesla Roadstar Structure and Layout of the two vehicle systems In an electric engine the numbers of components is fewer in number and are simpler in configuration. If one were to trace back the line of components starting from the tyres, the wheel axle connected to the tyres is driven by a motor. Similar to controlling speeds by regulating the quantity of fuel, the accelerator controls the voltage input into the motor which thereby controls the speed of the vehicle. The whole setup is powered by a battery and which can be charged from an external power source by simply plugging on to it. (Markel Tony, 2007) Compared to the IC engine which had power sources taken from the same shaft drive it is essential that power for operating the air conditioner and water pump are taken from individual separate motors. The battery should be connected to the motor using a controller so that large starting torques is avoided. (Electric and Plug-in Hybrid Vehicles, 2010) This can also bring a certain amount of automation in the working of the motor in regulating speed and bringing forth forward or backward motion. It also protects the motors from being subjected to high loads. A number of batteries are arranged in two slots and must be capable of generating 300V DC. (Basic Electric Car Engine Overview, 1999) The Internal combustion on the other hand has a number of components that are required for its efficient working. A four stroke combustion cycle in an Internal Combustion engine follows the Otto Cycle. (Basic Electric Car Engine Overview, 1999) The combustion and the power thus generated takes place in an enclosed space. This cycle has four strokes which namely are 1. Intake stroke- As the piston contained in the engine begins its downward stroke, the inlet valve opens admitting fresh air that has been mixed with gasoline in a certain ratio, into the system. 2. Compression- The cylinder moves up and compresses the air thereby increasing both its density and temperature. 3. Combustion – A spark plug located at the top introduces a spark into this charged mixture. The leads to the downward motion of the piston creating the power stroke. 4. Exhaust- The piston moves back upward thereby expelling the burnt gases outside providing space for fresh intake. Electric vehicles and aerodynamics It is true that the number of components of an electric car is lower than a traditional car and the profile of the electric car can be readily modified to increase its aerodynamic efficiency. However a point of concern is the weight of the batteries that would otherwise increase drag and lower aerodynamic efficiency. By installing an effective nose grille at the front of the car, the air that remains stagnated in the frontal region of the car around the motor and gearbox is rerouted to flow past these areas and thereby reduce drag. The La Chevrolet Malibu has shutters in the lower grille region that are controlled electronically and automatically. (Industry, Research and Energy, 2010) As the speed of the vehicle increases the shutters close to allow the air at high speeds to flow past the vehicle. This reduces drag and also gives an impetus to the aerodynamic quality of the vehicle. Fuel efficiency is also increased. (Markel Tony, 2007) In the Honda Civic which has a Hybrid variant has aerodynamic hubcaps that are fixed to the rear end spoilers. This has lead to a reduction of aerodynamic drag from 0.3 to 0.27. The overall effect of such a drag reduction is that power requirement has reduced by 1.6%, storage capacity requirement has reduced by 2.2% and the overall energy consumption has decreased by 3.2%. (Markel Tony, 2007) Climate and noise control in electric engines Climatic control and reduction in noise form an important parameter in a potential customer selecting an electric hybrid car over a traditional car working on an internal combustion engine. The Battery Electric Vehicle (BEVs), Plug-In Hybrid Electric Vehicles (PHEVs) and the Hybrid Electric Vehicles (HEVs) are all electric vehicles powered by motors. In these concepts there are no separate drive shafts since the drive motors are placed inside each wheel. (Industry, Research and Energy, 2010) These motors are responsible for providing both the driving force and the braking force. This therefore has a great significance in reducing the amount of noise that is generated. Source: Shim et al, 2009, comparison of 2 hybrid models The other significant criteria are the amount of amount of heat that is generated during the working of the fuel cells. While it is still less when compared to the conventional internal combustion engine, the use of Ni-MH batteries for most hybrid cars poses challenges in controlling the amount of heat discharge. The next variant in improving engine performance is the Li-Ion battery which has a higher energy density compared to Ni-MH batteries but produce even more heat during charging and discharging. (Marcos J et al, n.d ) Fully digital smart and lead-acid battery charging system is being improved and its salient features include short recharging time. The battery life also increases and the heat during discharge is reduced considerably. Source: Shim et al, 2009, Comparison of Ni-MH & Li-Ion battery Life Cycle assessment of an electric vehicle A Life Cycle assessment of an electric vehicle is done with respect to two other vehicles namely a CNG vehicle that runs on compressed natural gas and a diesel bus which is an internal combustion engine. The output from each system to the environment is assimilated and fuel efficiency ascertained. (Electric and Plug-in Hybrid Vehicles, 2010) The net impact on the environment is tabulated using a set of factors that determine the net impact of these different modes of transport on the environment. 1. Global Warming Potential or GWP – The Global Warming Potential of three modes of transport are carried out. The Fuel cell which is advancement to the electric vehicle takes lesser time to get charged but poses of maintenance. The production of hydrogen for the fuel cell leads to large amount of greenhouse emissions due to the energy spent during crude oil extraction in the initial phases. (Ally Jamie, 2008) The Fuel cell buses have therefore a net greater GWP than the current buses that run on diesel. However significant improvements are on the anvil to reduce this effect. 2. Photochemical Ozone Creation Potential (POCP)- While it is true that emissions from a electric vehicle running on a fuel cell is less at the urban centres where the vehicle is operating the amount of emissions that are produced in the refinery to build this fuel cell system is quite significant. The emissions from a diesel based engine are in the form of nitrogen oxides, carbon monoxides and carbon dioxides. However in the case of fuel cells these emissions are in the form of Non-methane Volatile Organic Compounds (NMVOCs) that are generated during crude oil extraction. (Ally Jamie, 2008) The amount of emissions of a CNG vehicle is less compared to both the diesel and Fuel cell forms and is mostly in the form of methane emissions. Source: Shim et al, 2009, Car Comparison 3. Acidification Potential (AP)- The acidification potential of fuel cells is quite significant due to the amount of amount of sulphur dioxide emissions that are generated during the extraction of platinum.( Ally Jamie, 2008) These emissions are quite harmful for human consumption. 4. Eutrophication Potential (EP)-Comparing this is insignificant since both the forms; the diesel engine and the fuel cell have the same amount of eutophication potential. While one has a the Nox emissions occurring at the areas where the vehicle is operating the Fuel cell for the electric vehicle produces these emissions at the refinery. (Ally Jamie, 2008) It could be argued the immediate effect of the pollution is caused by the diesel vehicle due to its proximity to human existence around it but the net impact of both these forms on the environment are almost same. Source: Ally Jamie, 2008, Life Cycle Assessment 5. Primary Energy Demand- The demand for Fuel cell powered vehicles are on the rise die to the simplicity of the internal engine parts and also due to the ecological balance it provides to the environment. (Ally Jamie, 2008) Source: Shim et al, 2009, comparison of electric cars with other IC engine models Since noise and pollution in the form of emissions are absent at its area of service these have great demand in urban centres having high population density although on assessing the total impact of these on the environment, there is lot of scope for improvement. Reference List 1. Marcos J et al, n.d, A fully digital smart and fast lead-acid battery charge system 2. Markel Tony, 2007, Platform Engineering Applied to Plug-In hybrid electric vehicles, National Renewable Energy Laboratory 3. Ally Jamie, 2008, LCA of the Hydrogen Fuel Cell, natural Gas and Diesel Bus Transportation Systems in Western Australia, Department for Planning and Infrastructure 4. Industry, Research and Energy, 2010, Challenges for a European Market for Electric Vehicles, Directorate General for internal Studies. 5. Shim et al, 2009, The Emergence of New types of power train and the impact on the Insurance Industry, Motor Insurance Repair Research Centre 6. Electric and Plug-in Hybrid Vehicles, 2010, Available at http://www.etsap.org, [accessed on 31st May] 7. Basic Electric Car Engine Overview, 1999,Available at http://www.carsdirect.com, [accessed on 31st May 2010] Read More