Electric and Hybrid Cars - Report Example

Electric Cars Introduction Alternative energy is considered as any other energy source that is an alternative to fossil fuels. The precise definition of alternative energy has varied over time and until now, there is not a single discrete definition for alternative fuels. Generally, alternative energy is currently perceived as energy that is harnessed and recovered without harmful or undesirable effects on the environment, e.g. carbon dioxide emissions, or greenhouse gas effects. Alternative energy includes sources that are clean, renewable and sustainable such as solar power, wind, biomass, wave and tidal energy. Alternative energy sources have numerous applications across a broad platform. They are mainly converted to electric power in order to do useful work. This electricity can then be used to do various tasks like lighting homes, powering manufacturing industries, and in the automotive sector. This paper is going to focus on the role of solar power as an alternative energy source to power electric and hybrid cars. Electric cars and Hybrid cars An electric car is an automobile vehicle that is propelled by one or more electric motors. The electric motors are powered by electric energy stored in rechargeable batteries or capacitor banks or any other energy storage device. Electric cars have a competitive advantage over fuel-powered cars in that the motors provide instant torque, which creates smooth and strong acceleration. A hybrid car is a vehicle that is propelled by two or more distinct energy sources. Most of the hybrid vehicles feature a combination of an internal combustion engine and one or more electric motors. However, other methods to harness and use energy may be incorporated in the mechanism (Argueta, 2010). Hybrid cars have various energy sources, which include electricity from batteries, electromagnetic fields, hydrogen, fuel cells, solar power, and petrol, diesel, on board or out of board rechargeable energy storage system. Solar cars A solar car is an electric car completely or partially powered by energy from the sun. The cars are usually fitted with solar panels that feature photovoltaic cells to convert the suns energy to electrical energy. This electrical energy harnessed from the sun is used to power part or all of the cars propulsion drives, hence the term solar car. The solar power generated is used to power other features like the cars communication or control systems and various auxiliary functions (Craddock, 2008). Solar cars are usually fitted with measurement, and data collecting instruments like other convectional cars. The information is usually displayed on gauges and the driver has to keep monitoring them in order to keep the car running smoothly and recognize possible anomalies that may occur while driving. Wireless telemetry is sometimes used, in order to relay date between the car and the driver’s team. This makes the driver’s work a lot easier because the team takes responsibility in monitoring the car’s performance. The team monitors the cars energy consumption, the amount of solar energy harnessed and other parameters as the driver is left to concentrate with the driving. How solar cars work Solar cars run on solar panels that employ photovoltaic cells to convert the sun’s radiation directly to electricity. Unlike solar thermal energy, which converts solar energy to heat, photovoltaic cells transform sunlight directly to electric current. When radiation from the sun hit a photovoltaic cell, it excites electrons and causes them to flow which results in an electric current by the photovoltaic effect. The photovoltaic effect is a result of voltage or current being created from in a material upon exposure to radiation (Fletcher, 2011). Photovoltaic cells comprise of crystalline semiconductor materials like silicon or gallium. The solar panels are composed of several photovoltaic cells combined together to convert sunlight to electric current. The total number of photovoltaic cells used depends on the amount of power needed and design constraints used to make the car. The photovoltaic cells are connected together to form modules, the modules are then joined combined to form a panel. The solar panels can then be mounted on the car in several ways. The choice of geometry depends on several factors, which include, surface area exposed to sunlight, power output, aerodynamic resistance, weight and other practical possibilities. The optimization of these factors is a subject in the overall car’s design and efficiency (Fletcher, 2011). Once the solar energy has been harnessed and converted to electric current, the electricity can either be stored as chemical energy inside a battery or fed directly to the motor. The weight of the battery affects the overall weight of the car. Solar cars are purposely designed to be as light as possible in order to improve the efficiency and performance of the car. If other factors are kept constant, a lighter car will generally be faster than a heavier car. When the car is turned off, the solar power harvested will be used to charge the batteries. When the car is turned on, the motors will draw current from the battery and convert the electrical power to mechanical power using the motoring effect. The electric current drawn by the motor cuts through a magnetic field, the interaction between the current and magnetic field creates motion, which rotates the motor’s shaft (Craddock, 2008). The motor’s shaft is then coupled with the wheels hence transferring power which making the wheels rotate. Solar cars usually use relatively small motors and achieve speeds compared to a typical family car. To coordinate all this functions, solar cars have on board controllers. These controllers take signals from the driver and feed them to the motors. The controllers control the amount of power fed to the motors and the amount of solar power fed to the batteries. They also prevent the battery from over charging by cutting off the charging current once the battery has achieved its maximum capacity (Argueta, 2010). When the battery is full and the solar car is being driven, the controller sends the solar power directly to the motors. It is also the work of the controller to ensure that the motors do not draw excess current. The controller takes the driver’s commands, which in turn accelerate or decelerate the car depending on the commands sent by the driver. Optimizing energy consumption is very important, especially in solar car races. Drivers and teams have to keep monitoring and adjust the car’s energy parameters. When the vehicle is travelling fast, all the power from the solar panels is used, and at times when extra speed and acceleration is needed, power may be drawn from both the solar panel and the battery to optimize the motors performance. Choices of route and weather conditions are among the strategies considered by racing teams. Environmental aspects Electric cars are not considered as environmental pollutants mainly because they do not emit exhaust materials that pollute the environment. Cars powered by internal combustion engines emit exhaust gases containing carbon and nitrogen compounds that poison the atmosphere. These gases contribute to the green house effects experienced in urban areas that have numerous gasoline-powered cars. In terms of environment conservation, Electric cars have the advantage because they do not produce exhaust materials that pollute the environment (Pistoia, 2010). Electric cars are relatively quitter than gasoline vehicles; this is because of the electric motors used to propel them. Electric motors have less noise compared to internal combustion engines. Energy sources In terms of powering cars, electric motors have several advantages over other energy sources such as internal combustion engines. Electricity can be harnessed from a number of non-pollutant sources like wind energy, hydroelectric power, solar energy, geothermal energy which have no exhaust emissions that pollute the environment (Pistoia, 2010). Internal combustion engines depend on fossil fuels, which produce environmental hazards from their mining, processing, production and use. The main disadvantage of electricity over fossil fuels is storage and capacity. Electricity needs to be stored in heavy batteries that take a significant amount of time to fully charge. Once these batteries run out of power, the electric car has to stop and charge unlike gasoline cars that can just roll in a petrol station and get fuel instantly. Electric drives are much more efficient in terms of delivering power to the wheels. Electric motors provide instant torque unlike internal combustion engines whose torque varies. The torque in an electric drive can be varied directly in the motor hence eliminating the need for a gearbox. Impact on car manufactures Most of the car manufacturers in the world make cars that are powered by petroleum fuel rather than electricity. This is because of the availability and popularity of petroleum fuels. This dependence has grown over a long period from the past. Petrol is readily available to be purchased and used almost everywhere where a car can reach. The dependence on petrol has been so strong such that manufacturers are reluctant and skeptical to manufacture vehicles powered by alternative energy sources. Combustion of petrol fuels has low efficiency. Most of the energy produced is dissipated as waste heat by the engine. Converting this waste heat to useful work has been a big challenge to manufactures. Conclusion With the environmental awareness currently growing, cars powered by fossil fuels have been identified as among the major participants of atmospheric and environmental pollution. Growing concerns from governments and institutions have imposed policies on car manufacturers in order to mitigate and control the exhaust emissions produced by petroleum-powered cars. These policies intend to force car manufactures to improve work on their design in order to reduce pollution. The fluctuating prices of petroleum have also rendered petrol a bit too expensive. In response to this, manufacturers will consider pursuing alternative sources to power their cars. In addition, with the promising trends in electric cars popularity, availability of cheap electric power and the improvement of battery technologies, the future of automobile is going to be powered by electricity. References Argueta, R. (2010). A Technical Research Report: The Electric Vehicle. University of California Santa Barbara College of Engineering Craddock, D. (2008). Renewable energy made easy: free energy from solar, wind, hydropower, and other alternative energy sources. Ocala, Fla Atlantic Pub. Group. Fletcher, S. (2011). Bottled lightning: super batteries, electric cars, and the new lithium economy. New York: Hill and Wang. Pistoia, G. (2010). Electric and Hybrid Vehicles: Power Sources, Models, Sustainability, Infrastructure and the Market. Amsterdam: Elsevier. Read More