SUMMARY
Global warming is a serious issue that threatens the survival of future generations. Various methods are being devised to reverse the effects of global warming such as the use of green energy. Motor vehicles running on fossil fuels produce greenhouse gases which are a major cause of global warming. Therefore, it’s almost impossible to address the issue of global warming without considering emissions from the transport industry. Electric vehicles are a viable and environmentally friendly alternative to internal combustion engine vehicles that combust fossil fuels. The vehicles are powered by a rechargeable battery that drives an electromagnetic motor. Electric vehicles produce no emissions as they do not combust fossil fuels but are instead recharged through electrical outlets. It is possible to make electric vehicles carbon neutral by recharging them through solar power. Solar photovoltaic energy is a clean form of renewable energy that converts the sun’s radiation to electricity.
INTRODUCTION
Vehicles are an essential component of the modern life as they ease transportation and movement from one place to another. However, motor vehicles have a negative impact on both the environment and the economy. The environmental impact of vehicles emanates from the combustion of fossil fuels in internal combustion engines. Fossil fuels are essentially hydrocarbons with high amounts of carbon and hydrogen. During combustion, the carbon-hydrogen chemical bonds decompose to form carbon dioxide and carbon monoxide. Also, impurities in fuel cause the release of other toxic gases such as methane and hydrogen sulfide (A blanket around the Earth par.2). These gases accumulate and form a blanket like layer above the atmosphere. Radiation from the sun manages to penetrate the toxic gas layer to reach the earth surface. However, radiation reflected from the earth’s surface have large a wavelength and hence low amounts of energy. As a result, the reflected radiation is unable to penetrate gas layer and escape to space leading to accumulation of heat in the atmosphere, otherwise referred to as global warming.
As the word becomes more developed, more vehicles will continue to be manufactured. Hence, more tons of greenhouse gases will be emitted. Global warming, which is characterized by rising global temperatures leads to the melting of polar ice, which further leads to rise in sea levels. Rising sea levels can displace communities living in coastal and low lying regions that are below sea levels. Also, melting of polar ice can alter the flow of ocean currents that move from equatorial regions towards the pole (Causes of Climate Change par.5). Such change in current flow can lead to changes in weather patterns, which can be detrimental for people who depend on farming. Also, toxic gases emitted from vehicles can accumulate in the atmosphere and cause chemical fogs, which cause respiratory diseases in human beings (Cause and effect for global warming par.4). From an economic aspect, overdependence on fossil fuels has a huge impact on global economies due to oil’s high correlation with the cost of living.
Also, electric cars can be categorized based on the type of battery used, such as a lead acid battery or a fuel cell. Finally, electric vehicles can be classified according to the type of motor used, either an alternating current motor or a direct current motor (Hamilton par.4). This report will discuss how electric vehicles can be used to mitigate the effects of greenhouse emissions from internal combustion engines. As an engineering student, I possess in depth knowledge on internal combustion engines, electric vehicles, and electrical systems. Also, I understand the impact of emissions from vehicles and how electric vehicles can be used to mitigate these effects.
CURRENT SITUATION
How internal combustion engine vehicles cause global warming
All internal combustion engines produce toxic and greenhouse emissions. These emissions are partly due to unburned hydrocarbons, which lead to the formation carbon monoxide and other byproducts of the combustion process such as carbon dioxide. Fuel impurities constitute the toxic gases in engine emissions. Such gases include nitrogen dioxide (NO2), nitrogen oxide, sulfur dioxide (SO2), and methane (Causes of Climate Change par.6). Also, internal combustion engines emit particulate matter, such as carbon particles or soot, that gets suspended in the atmosphere and can therefore be inhaled. Hydrocarbon emission from internal combustion engines on the other hand includes gases such as benzene, frormadehyde, acrolein, acetaldehyde, and polycyclic aromatic hydrocarbons.
Greenhouse gases, up to a certain extent, are beneficial to the environment as they raise the earth’s temperature to a point where it can support life at around 15 degrees Celsius. However, increased accumulation of greenhouse gases raises the global temperatures to a point where they are no longer beneficial for the survival of earth as a planet (Hamilton par.5). The increased rise in the amount of greenhouse emissions in the atmosphere has led to rise in global temperatures in the last 200 years as shown by figure 1 below.
Figure 1: The rise in global temperatures due to the presence of greenhouse gases. Source: Timeforchange.org, http://timeforchange.org/cause-and-effect-for-global-warming
Since the earth is not a perfect reflecting surface, some of the radiation energy is absorbed by the earth’s surface while only a small portion is reflected. The reduced energy in the reflected radiation results to higher wavelengths in the radiation. As a result, the radiation is trapped in the atmosphere by the layer of greenhouse gases in the upper levels of the atmosphere (A blanket around the Earth par.4). The trapped radiation is then emitted in various directions whereby it heats up the lower layers of the atmosphere and the earth’s surface as shown in figure 2 below.
Figure 2: An illustration of how global warming occurs due to presence of greenhouse gases in the atmosphere. Source: NASA's Jet Propulsion Laboratory, http://climate.nasa.gov/causes/
Available solutions for motor vehicle emission
Electric vehicles are a possible replacement to the fossil-fuel-driven vehicles. Pure electric vehicles are powered solely by a battery and driven by a motor. As such the battery in the vehicle have to have neough capacity to drive the vehicle fro the required distance range. When the battery charge runs out, it has to be recharged again from an external power source. Pure electric vehicles normally have a 100 miles drive range. The pure electric vehicles do not burn any fossil fuel and therefore have zero emissions (Hamilton par.5). Figure 3 below illutrates a siplified power train of an all electric vehicle.
Figure 3: Power train of pure electric vehicle. Source: Bureau of Labor Statistics, http://www.bls.gov/green/electric_vehicles/
However, pure electric vehicles face severe limitations and operational inefficiencies such as the limited mile range and dependence on the availability of charging stations. To counter these limitations, vehicle manufacturers developed the hybrid electric vehicles. Hybrid electric vehicles are driven by both an electric motor and an internal combustion engine. An electric car can have the engine as the primary power source and the motor as a backup. According to Halderman, the vehicle can be configured to run primarily on the electric motor and an internal combustion engine to complement it when the charge state runs low (19). Figure 4 below shows the power train of a hybrid electric vehicle.
Figure 4: The power train of an electric vehicle with both an internal combustion motor and an electric motor and a battery. Source: Bureau of Labor Statistics, http://www.bls.gov/green/electric_vehicles/
Hybrid electric vehicles are able to overcome the limitations faced by pure electric vehicles. This is because the engine in the vehicle is coupled to a generator that charges the battery while driving the vehicle at the same time. As such, the vehicle exhibits a longer mile range as the battery takes over when the fuel runs out (Hamilton par.6). Also, the vehicle can venture to areas without charging outlets as it can be fueled at traditional petrol stations. Finally, both types of electric vehicles benefit from a phenomenon referred to as regenerative braking. Regenerative braking converts kinetic energy lost by the vehicle to electric energy, which is then used in charging the battery with further increases in the mileage range.
Limitations of electric vehicles in reducing global warming
Electric vehicles are designed to mitigate the greenhouse effects of fossil powered vehicles. However, the vehicles to do not completely eliminate the carbon footprint of the transport industry. This is because the vehicles are charged using electric energy generated in power statuins that burn fossil fuels such as coal, natural gas, or diesel (Halderman 45). As such, the electric vehicles only eliminate the decentralised emissions from discharged from individual vehicles but increase the power load on the power generating stations, which further raises their carbon footprint.
Proposal for mitigating the shortcomings of electric vehicles: Solar charging stations
Solar charging sustems can be designed for private use whereby the solar panels are mounted on rooftops. Such systems are optimised to charge a single car overnhitght. Also, solar charging systems can be optimised for public use, such as along highways and in public facilitis such as colleges (Demont-Heinrich par.3). Electric vehicle charging systems designed for public use are enhanced for high speed charging so that a high number of vehicles can be recharged within a short time. Figure 5 below shows the proposed design of a public solar electric vehicle charging station.
Figure 5: A public solar electrical vehicle charging station. Source: Solarchargeddriving.com, http://solarchargeddriving.com/2016/04/12/quebec-gets-new-solar-ev-charging-station/
CONCLUSION
Motor vehicles burn fossil fuels in their internal combustion engines to create mechanical energy for propulsion. Combustion of fossil fuels leads to the emission of greenhouse gases such as carbon dioxide, methane, sulfur dioxide, and nitrogen oxides. These gases accumulate in the atmosphere and trap radiation reflected from the earth’s surface leading to global warming. Electric vehicles offer a plausible solution for the reduction of the carbon footprint of the transportation industry. The vehicles are powered by an onboard battery, which eliminates the need for internal combustion engines. However, electric vehicles are charged using electricity generated in power plants that combust fossil fuels, which negates emission reduction by electric vehicles. Solar charging stations offer a carbon neutral option for vehicle charging applications. The solar stations can be put up in homes, along highways, and on public facilities such as colleges. The use of solar to charge electric vehicles can improve the efficiency of electric vehicles as a means of mitigating the effects of greenhouse emissions emanating from the transport industry.
Works Cited
“A blanket around the Earth.” Earth Science Communications Team. NASA's Jet Propulsion Laboratory, 19 April 2016. Web. 20 April 2016. <http://climate.nasa.gov/causes/>
Hamilton, James. “Careers in Electric Vehicles.” Bureau of Labor Statistics. United States Department of Labor, n.d. Web. 20 April 2016. <http://www.bls.gov/green/electric_vehicles/>
Demont-Heinrich, Christof. “Quebec gets new solar EV charging station.” Solarchargeddriving.com. n.p., 12 April 2016. Web. 20 April 2016. <http://solarchargeddriving.com/2016/04/12/quebec-gets-new-solar-ev-charging- station/>
“Exploring New Energy Sources: Solar Electric Vehicle Charging Station.” Facilities Management. The University of Iowa, 2009. Web. 20 April 2016. <http://www.facilities.uiowa.edu/uem/renewable-energy/solar-energy.html>
“Causes of Climate Change.” United States Environmental Agency. United States Environmental Agency, 24 February 2016. Web. 20 April 2016. <https://www3.epa.gov/climatechange/science/causes.html >
“Cause and effect for global warming.” Time for Change. Timeforchange.org, 14 January 2007. Web. 20 April 2016. < http://timeforchange.org/cause-and-effect-for-global-warming>
Halderman, James D, and Tony Martin. Hybrid and Alternative Fuel Vehicles. Upper Saddle River, NJ: Pearson Education/Prentice Hall, 2011. Print.
