The development of a world population has forced the use of energy very fast in large quantities in order to preserve the continuity of human life. When this energy source is the most widely used oil and other mineral fuels such as natural gas and coal, exploitation of such materials as an energy source has caused various environmental problems such as increased air pollution, greenhouse gases cause global warming and Another problem leads to scarcity of fuel due to these energy sources are not renewable.
Using water as fuel are expected to overcome these question, besides there are also abundant in the earth's emissions of water-fueled vehicles do not cause environmental problems such as those caused by fossil fuels. Vehicles with solar photovoltaic systems and fuel cells are one alternative solution, where water can be directly converted into hydrogen and oxygen which it will be then flowed into the fuel cell system to generate electricity to drive the vehicle. One advantage of this kind of vehicle is not necessary to use hydrogen storage system so that the price of this vehicle production will be cheaper.
Fuel cells are electrochemical energy conversion device which those will convert hydrogen and oxygen into water, simultaneously produces electricity and heat energy in the process of electrochemical systems (Booth, 1993). The structure of the fuel cell device consists of an electrolyte layer that bergubungan with porous anode and cathode on both sides. Scheme of a complete fuel cell systems with reactants, products and ions flowing through the electrolyte is presented in Figure 1.
Figure 1. scheme of individual fuel cell system
In the fuel cell, hydrogen gas as fuel interacts continuously with the anode as the negative electrode and oxygen is consumed at the cathode as the positive electrode. Electrochemical reactions occur at the electrodes to produce an electric current. Characteristics and components of the fuel cell itself is similar to batteries in general, there is a difference only in some parts. Batteries are energy storage devices, the maximum amount of energy contained in a battery depends on how big your battery to accommodate as a reactant chemicals, electrical energy is produced when the reactants are consumed (discharged). For some types of battery used for this, the reactants can be regenerated with the re-filling (recharging) by using energy from other sources. On the other hand, the fuel cell is an energy converter device, where electrical energy will continue to be produced as long as there is still a supply of fuel to the electrode (Jacoby, 2003).
Currently in developed countries has been developed to be based on fuel cell vehicles, where vehicles are not mengimisikan CO2 and other harmful gases but emit only water vapor is in no way harmful to the environment.
Sensitizer Dye Solar Cell (DSSC)
Conversion of solar energy into electricity is done by applying the photovoltaic system. Today, the development of solar cell using semiconductor devices has been so rapid. It simply put photovoltaic solar cell consists of junction p-type semiconductor material and n (pn junction semiconductor) if sunlight will produce a flow of electrons or so-called electricity.
Dye sensitized Solar Cell (DSSC) is a third generation solar cell silicon-based solar cells and solar cells based on polycrystalline semiconductor as its predecessor. In a conventional solar cell, photons or sunlight interacts with the semiconductor which then produces electricity. While in the DSSC, dye (dye) placed on the semiconductor surface interacts with photons as light harvesters (Light harvesting). Theoretically, the resulting efficiency of DSSC is better because the dye works on the region of visible light to be infrared, the wavelength range (energy) is wider, while the semiconductor can only interact with ultraviolet (UV) that in fact most of the UV rays do not arrive at the Earth's surface because of being blocked by the ozone layer (Gratzel, 2001).
Compared with the previous two generations of DSSC, it has many advantages both in terms of efficiency and in terms of production cost. Within ten years of research for solar cell efficiency achieved by this type has to match the solar cell efficiency achieved prior to the study has been conducted for twenty-five years. In terms of production cost, DSSC is cheaper, with the ease of obtaining raw materials and fabrication process. One example of ruthenium complex compounds are presented in Figure 2.
Figure 2. Complex Rhutenium N3 dye (cis-RuL2 (NCS) 2 (Gratzel, 2003)