It is highly fascinating to imagine a vehicle completely devoid of the bulky internal combustion engine, and instead, powered by the natural solar energy. Obviously, such recommendations are bound to be bombarded with a series of valid questions from the other side. These would be regarding the quality and comfort trade-offs associated with the switch to solar power, the capabilities of a solar car, the costs involved in the purchase of such a vehicle, the maintenance pre-requisites and above all, the comparison to a conventional fossil fuel driven car.
The black cloud that looms large over all our natural resources like coal and petroleum has forced all of us to seriously look at alternatives for our present energy utilization trends. People are appreciating the idea of a car that derives all its energy needs from the inexhaustible source of heat – the Sun. Not only would a solar powered vehicle overcome the polluting nature of petroleum and diesel driven vehicles, but also the reduced running costs of such a vehicle makes the prospects of full fledged solar cars a particularly exciting one. Thankfully, the bottlenecks generally associated with such a far fetched idea have been tackled to a great degree by researchers and developers all across the globe. The concept of solar cars is alive and kicking in automotive quarters of the world, and actual solar cars are quickly bridging the gap between the high tech science exhibition stalls and the actual road they are meant to be driven on.
Solar cars use the heat energy from he Sun as fuel. This sounds bedazzling at first, but actually, the transformation of solar energy into an equivalent of fuel is a step by step logical process. It is anybody’s guess that the first and foremost requirement in the prototype of a solar car would be a device that transforms energy from the sun into some form that can drive the vehicle. Such a device is called a transducer. The transducer that transforms solar power into current, or electrical energy, is a solar photovoltaic cell. Thus, a solar car actually uses the solar energy as a raw material for the eventual driving force. Coming back to the point of solar photovoltaic cells, a heavy assembly like a car would obviously need a lot of electric current, implying a lot of energy transformation, which further implies a large assembly of small photovoltaic cells that perform the task of large scale energy conversion. This is achieved through the installation of solar panels, which are nothing but a congregation of many photovoltaic cells arranged in an array. This panel is mounted on the car roof, so that maximum sunlight falls on it. Sunlight instigates the motion of electrons among the layers of solar cells, and the resultant electric current becomes a useful energy form for the car. Electrical energy may be stored in a battery, in the form of chemical energy. Otherwise, it may be directly coupled to electrical motors.
In a solar car, a battery pack replaces the conventional fuel tank. The battery stores the radiant solar energy in a chemical form when the motor of the vehicle isn’t running. Among the different sorts of batteries used in a solar vehicle, the most prominent ones are include lead acid battery, nickel metal hybrid (NiMH) battery, nickel cadmium (NiCad) battery, lithium ion battery, and lithium polymer battery. Though lead acid batteries continue to be more popular, but ongoing research is directed towards tapping the higher efficiencies of nickel metal hybrid solar cars which are somewhat demanding on the maintenance front.
The solar panel constitutes the gist of the energy transformations involved in a solar car. However, there is a lot more mechanical, electrical and electronic engineering behind a successful solar vehicle. The electricity flowing in the motor driving system requires persistent monitoring, and this purpose is solved by the power electronic segment of the vehicle’s architecture. A sophisticated power electronic system for a solar car comprises a motor controller, peak power trackers, and a data acquisition system. The peak trackers play a particularly important role in the functioning of a solar vehicle, as they are responsible for supplying appropriate power to the motor balancers of the car for highest possible efficiency, and for retaining the excess electricity produced from the solar panel in the battery. The batteries run the risk of being damages due to reception of unpalatably high content of current, but the peak tracker provide for the monitoring of the electrical energy received by the battery. The number of such trackers in a car design may vary from one model to another, but they remain at the heart of every power electronic assembly inside a solar car.
As the name suggests, a motor controller or motor balancer controls the electrical energy being fed to the motor of the vehicle, as necessitated by the acceleration demands of the driver. With the advent of times, the trend of automatic gear shifting cars has caught the fancy of people, and the same has reflected onto solar cars as well. The power electronics of the solar car become a lot more complex in such a scenario, but the basis of the concept still remains the transformation of solar energy into an electrical form.
With their pollution free and economical working, solar cars make a strong case for themselves. In an ever aggravating energy crisis, the endorsement of solar cars becomes an unavoidable proposition. Diligent research activity in all corners of the world aims at improving in the prototypes of solar cars so that major car manufacturers can launch commercial versions of such vehicles for public use. Although the present day breed of solar cars exhibits impressive performance, but there is still scope for up-gradation, so that consumers overcome their inhibitions. Obviously, anybody would opt for a ‘green’ vehicle as it would let the buyer participate in the movement aimed at improving the environmental health of the planet, apart from giving him/her value for money.