What are the advantages of fuel cells?
1. Continuous source of energy: There is no electrode material to be
replaced as ordinary batteries. It runs continuously to produce power
by feeding the fuel in it. This is the reason H2 – O2 fuel cells have been
used in spacecraft.
2. High efficiency: These cells convert energy of the fuel directly into
electricity. Therefore these are more efficient. Efficiency is about 60 to
70% as compared to those of conventional methods of production of
electric energy that involve combustion of fuel with efficiency of 40%
3. Pollution free working: Since no objectionable by - products are
formed by the fuel cells they don’t cause pollution problems.
Fuel cells provide a range of critical benefits that no other single power technology can match.
Fuelled by pure “clean” hydrogen, fuel cells produce only pure water as exhaust. Even when powered by fossil fuels, they produce far less pollution than conventional technologies. Releasing the energy in a fuel through high-temperature combustion (as in an internal combustion engine) results in the creation of polluting nitrogenous and sulphurous oxides.
Fuel cells extract more energy from a fuel due to the increase in efficiency of electrochemical conversion over combustion. There are no moving parts in a fuel cell stack itself so there are no mechanical inefficiencies (compared with the Carnot Efficiency that limits normal engine efficiency). However, it should be well noted that the balance of plant introduces a large parasitic load. Furthermore, the heat produced in a fuel cell stack can often be used rather than wasted – a process known as Combined Heat & Power (CHP) generation or Combined Heat, Cooling and Power (Tri-generation). Generation of electrical power close to the electrical load (this is called Distributed Generation) allows the more efficient use of electrons and heat energy. Fuel cells also provide high efficiencies at partial loadings and at small sizes – both are important advantages over traditional energy converters. Many of these efficiency benefits are due to the modular nature of fuel cell design.
With no moving parts, fuel cell stacks themselves are silent and vibration-free. A fuel cell system needs pumps, compressors and other moving parts that do produce vibration and sound, but these are on a different order of magnitude than the sound and vibration produced by traditional combustion engine technologies.
A fuel cell is a cell that produces electricity from oxidation of a fuel contained within the cell. Both the fuel and the oxidise are contained within the cell and the oxidising reaction takes place between two electrodes in the cell producing electricity directly. Thus the fuel cell combine features of traditional power thermal power plants as well as cells.
In thermal power plants the electricity is generated by first burning the fuel to generate heat energy, which is then converted to electric energy. In the process of converting the available energy of fuel to electricity, considerable amount of heat energy is wasted. In comparison, energy cells can theoretically generate electricity with 100% efficiency, although in practice some heat energy is lost in fuel cells.
The difference between fuel cell and traditional cells is that in traditional cells the electrodes directly take part in the reaction to produce electricity, and in the process, whereas in fuel cells the the reaction takes place between the fuel and the oxidant. The electrodes of fuel cells do not get depleted during the process of generating electricity.
The main advantages of fuel cells over other means of generating power is:
- High efficiency.
- Light weight.
- They have no major moving parts therefore these are more reliable.
Because of there reasons fuel cell are used for remote applications and applications requiring high reliability. Most popular applications of fuel cells are in space stations, remote weather stations and military applications.