Global warming is the steady heating of the earth's surface, atmosphere, and oceans, and scientists have attempted to find strategies to manage heating levels in order to mitigate the ever-increasing environmental threat. According to Environmental Protection Agency data, the earth's temperature has risen by 1.4 degrees during the last century. Temperatures are anticipated to climb faster in the next 50 years if no action is taken (King, 2015). The world’s scientific organizations have accepted that global warming is a world’s disaster that is majorly caused by human activity ideally leading to increased emissions of carbon dioxide. Interestingly, as Student from the School Of Arts and Technology, I have joined the initiative of adopting environmentally friendly vehicles by inventing cheaper green transportation modes.
The figure above shows changes in global warming over the past century due from the transportation sector.
Transportation is a vital aspect of the human operation to foster both the economic and social aspect in this day and age. However, the current system of transportation has fronted a variety of problem to the environment. Currently, the transport attributes to more than 23 percent of the world’s greenhouse gas emissions. Of the total emission percentage road transport takes up to 75 percent, and if the problem is unabated, it is projected to increase more in the future. Therefore, the immediate solution to this menace is by greening the transportation sector that is done by developing a source of electricity that can be economical and easily rechargeable.
So the main culprit for global warming is carbon dioxide that is emitted from vehicles that form ozone smog and other fine particles due to chemical reactions leading to what is referred to as black carbon in the atmosphere (King, 2015). These, in turn, possess a threat to human health hence explaining the rapid rise in respiratory complications facing human kind. That is why I have proposed an attempt to use a solar electric system to combat the rampaging rise of black carbon in the atmosphere.
The calculations from the NASA Goddard Institute for Space Studies using the global climate model on how the emissions from vehicle gets into the air where they experience chemical and physical reactions that eventually lead to the formation of smog and particles that lead eventual damage of the ozone system exposing human life to danger. The results are shown below. Governments, business, car manufacturers and human beings are affected by the ever rising global warming, but I will focus on car manufacturers to help in salvaging the human aspects since our lives are in jeopardy (King, 2015).
Figure 1. Climate impacts measured regarding radiative forcing from the global and U.S. on-road transportation (ORT) and power generation (PG) sectors. The CO2 radiative forcing shown is for the 20-year time horizon. The sum of total non-CO2 and CO2 forcing is indicated above each bar
The graph above shows the reason why I have targeted the transportation sector because as compared to others it emits the largest portion of black carbon majorly due to the combustion of diesel engines. According to the statistical estimates of the power generation sector contributes less into the atmosphere. This calls for the need to switch the transport sector to an era of zero emissions that is by using some form of an electric power source of either plug in hybrid electric or solar/ pure electric technologies (Giannouli and Yianoulis, 2012).
Direct electricity might be costly and cannot be accessed in every part of the world that is why I have directed my attention to the use of solar energy that is trapped in the solar panels. It then gets transmitted to the vehicle battery or directly to electric motors leading to the combustion in the engine hence the vehicle gets powered. So here we are having like a free ride and the imagination of how wonderful it can be to continue enjoying the ride without spending your money on purchasing gallons of fuel which are also not eco-friendly.
Driving a solar powered car will make most of us realize the dream of an auto ride. The solar powered cars have solar panels that can be fitted on the car carrier then it operates like the solar systems in homes where it harnesses the energy from the sun then the magnetic field is created due to the sensitivity of the waves in the panel leading to a generation of energy. The energy charges the battery that runs the car's motor. Since batteries can at times be prone to failure due to fluctuating acidity levels, the solar cars can be able to direct the power to the electric motor without the interaction with the battery.
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How the solar cells work from my experiment
The photovoltaic cells (PVCs) forms the component of the solar panel system that is responsible for converting the energy from the sun to the electric form. The cells are made up of the semiconductors braced with silicon that takes in light. This energy triggers the flow of electrons because the semiconductor has free electrons. The flow, in turn, generates the electric current that gets the battery powered or the car motor (Giannouli and Yianoulis, 2012).
Silicon has unique chemical properties that exist in crystalline form, and the atom of silicon has 14 electrons that can be mixed with other chemical components to rise to 16 electrons that can be placed in three different arrangements. The first two shell arrangements get full and hold two to eight electrons, and the outer shell is nearly half full with about four to six electrons. So the atom will always look for ways of filling up its last shell meaning holds hands with the neighbors forming a crystalline structure. The major problem is that a pure crystalline silicon is a poor electrical conductor but the silicon in the solar cell is mixed with impurities to facilitate its conduction of electricity (Giannouli and Yianoulis, 2012).
By Brett Belan, Apparent Energy
I know we have the imagination that impurities are always undesirable but for this case, the solar cells cannot work without them since we want to improve on the conduction and retention of the solar electric energy. Consider silicon composed of an atom of phosphorous, for instance, in this case, one for every a million silicon atoms. Five electrons form in the outer shell of phosphorous but not four electrons. The bonding with the silicon neighbor atoms still take place, but in reality, there is one electron within the phosphorous that is hanging. It does not become part of the bond, but in its place, there is a positive proton in the phosphorous nuclear.
The addition of energy to a pure silicon in the form of heat, for instance, can lead to breakage of a few electrons and leave their atoms in the bond leaving behind a hole. The free electrons (free carriers) the roams around the crystalline lattice in the hope of getting another hole to fall into and carrying electric current. This makes the pure silicon to need too much light to convert sun rays into the desirable electric form that is needed to power the car motors or charge the car batteries.
The reason why I have proposed for the use of impure silicon in the solar panels is that it takes a lot less energy to break the extra phosphorous electrons that are not held in the bond with any neighboring atoms. The result of these is that most electrons break freely leading to more free carriers compared to pure silicon. Doping is the prevalent process of adding impurities when it is done in this case with phosphorous it results to N-type silicon which is a much better conductor than pure silicon hence a lot of electricity is generated to power the car or the solar vehicles.
A typical solar cell is doped with some element of boron having only three electrons in the outer shell as opposed to four. The result of this is P-type silicon it has free carriers and openings instead of the free electron. The next segment now involves putting the N-type and the P-type together. This is to create an electric field that provides a point of contact for the two elements that will enable the cell to work. The free electrons from N-type will rush to fill the openings on the P-type side. The electrons do not fill all the free holes, and this makes the whole set up useful. At the junction box in the panel, the electrons from both sides mix and then forms something like a barrier restricting the electrons from the N side to freely cross to the P side. It eventually leads to equilibrium and then the electric separates the two opposite sides. The electric field so created acts as a diode and allows the flow of electrons from the P side to the N side but not vice versa.
Light can be in the form of photons, and when it hits the, it’s energy result into the breakdown of electron hole pairs. Each will free one electron bringing in a free hole again. And if this happens the electron will be sent to the to the N side, and the hole gets to P side. This further disrupts the electrical neutrality and provision of an external current path will make the electrons to flow to P side hence uniting the holes that were sent by the electric field. This electron flow gives rise to the current the electric field yields the voltage. Both current and voltage give us power needed to propel the car engines (Parent, 2016).
There is still another challenge before using this cell since the silicon happens to be shiny that can trigger the photons to bounce away before the intended job is done. In reducing the loss of photons, an anti-reflective coating is engaged in the system. The final step is by installing a glass cover plate that can protect the cells. Several individual cells are connected to give rise to PV modules that can enhance the attainment of the required level of current and voltage that can give us power.
The cell still cannot absorb a lot of energy. But compared to early solar panels which reached an efficiency of 12 to about 18 percent, this proposed solar panel can achieve an efficiency of 79 percent. In 2006, the most effective solar panel that year reached the bar of 40 percent (source: U.S. Department of Energy). So the challenge as we can see is how to the visible light into strong electromagnetic waves, but fortunately enough I have offered guidance into it. The electromagnetic radiation constitutes several wavelengths. The wavelengths can manifest in the form of a rainbow.
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Since light wavelengths have the different energy potential, not all will produce sufficient energy to alter the electron-hole pair. This creates the band gap energy. The extra energy created by the photon might be lost, but fortunately, the effect of this energy loss is not significant (Parent, 2016). The problem of using the material of a narrow band gap to enable the usage of more photons is that the band gap for this cell determines the strength of the voltage. So to minimize the losses, the cells need to be covered by the metallic contact grid that bridges the distance that the electrons used to travel. Now that the cell is working, it can be fitted on top of a vehicle which is usually flat to tap the energy from the sun.
In dealing with bad weather, I will encourage the adoption of an automatic battery system that can and retain energy and can also automatically pick power when the solar energy is not sufficient. The cars should also be fitted with less sophisticated motors that do not utilize an excessive amount of energy. The battery to use for the solar panel should be lithium packed. The pairing of the electric vehicle with the solar panel also will minimize our contributors to the global carbon footprint.
The hope of solar revolution to save on the environmental impact of other sources of energy have existed for decades. Even though it is not always readily available to find solar cars in many dealerships but we can build ours with the given technological advances we are experiencing in this digital edge. Ed Passerini successfully constructed his own solar powered engine car which he named Bluebird in 1997 receiving lots of nods from scientists. The 2006 invention by the Ford Company that gave rise to Ford Reflex installed solar panels in their headlights and Mazda bringing solar cars with fitted panels on the roof to help charge battery are some of the highlights of effort towards achieving this indelible dream (Schwanen, Banister and Anable, 2013).
Conclusion
The global warming emission from the transport sector can be when we adopt the production of these clean and most efficient vehicles powered by the solar energy. This is a very seductive promise since on a bright sunny day the rays of the sun offer close to 1000 watts of energy for every square meter of the earth’s surface. If we can tap into all these energies, then I assure you that we could easily power our cars without using fuels and this will fulfill the agenda of green transportation.
References
Bhattacharjee, P. (2010). Global Warming Impact on the Earth. International Journal of Environmental Science and Development, pp.219-220.
Giannouli, M. and Yianoulis, P. (2012). Study on the incorporation of photovoltaic systems as an auxiliary power source for hybrid and electric vehicles. Solar Energy, 86(1), pp.441-451.
King, R. (2015). Solar cars race for the future results of the GM Sunrayce USA and the world solar challenge. Solar Cells, 31(5), pp.395-424.
Parent, M. (2016). New Technologies for Sustainable Urban Transportation in Europe. Transportation Research Record: Journal of the Transportation Research Board, 1986, pp.78-80.
Schwanen, T., Banister, D. and Anable, J. (2013). Scientific research about climate change mitigation in transport: A critical review. Transportation Research Part A: Policy and Practice, 45(10), pp.993-1006.
Xu, T., Shen, Y. and Zhang, W. (2016). In-Situ Steering Dynamics Analysis of Skid Steering for Articulated Motor-Driven Vehicle. SAE International Journal of Passenger Cars - Mechanical Systems, 9(2).
