Regardless of these numerous advantages of fuel cells over outdated batteries, there are still various controversies around the notion of using fuel. Society does not like to change (maybe try using alter or modify instead of change) their conventions. People get attached to certain things or methods of executing tasks and they refuse to give them up. This phenomenon tends to slow down the progress in technology especially the ones that are radically different from its ancestral technology.
When considering fuel cells, one of the many doubts that arise in the minds of the general public is about the validity of fuel cells being environmentally clean. A controversy that revolves around fuel cells is the environmental impact caused during manufacturing. The production of fuel cells requires a massive and unique infrastructure that is inclusive of equipment and systems needed to produce, distribute, store, as well as dispense hydrogen as a fuel to use PEMFCs. Additionally, common methods used to produce hydrogen are expensive and leave huge carbon footprints on the environment.
A common way to isolate hydrogen is through fuel reforming [3]. Fuel reforming is done by reforming hydrocarbon fuel sources such as gasoline and natural gas to extract hydrogen to use as a fuel for fuel cells [4]. This method requires a catalyst (typically platinum) to separate electrons from protons. Water and carbon oxides are a result of reforming hydrocarbons, which can cause carbon monoxide poisoning [1]. Thus, employment of a subsystem to minimize those carbon footprints is a necessity. The use of catalysts and subsystems are an additional cost.
Using such a method for the purpose of hydrogen extraction serves no advantageous purpose. Fossil fuels are used directly for hydrogen extraction labeling fuel cells as inefficient and a pollutant technology Firstly, extracting any fuel demands external energy. Although it takes a higher than average energy to isolate hydrogen, one must realize that even extracting gasoline from a well requires an energy input [5]. Fuel cells can be made more efficient than their present state if isolating hydrogen could be made cheaper. A cheaper way to separate hydrogen is electrolysis.
Electrolysis includes using electrical current to split the water molecule into its main components – hydrogen and oxygen – and then containing those components as fuel. Here lies the misconception: when introduced to electrolysis, most people think that the electrical current will come from energy produced by fossil fuels. This, however, is far from the truth. Contrary to fuel reforming, electrolysis does not require the use of another fossil fuel to produce hydrogen. Renewable sources of energy can be used to power an electrolyser.
Thus, hydrogen separation will cause zero carbon footprints because the use of fossil fuel is completely eradicated. This allows PEMFCs to have a minimal impact on the environment because no greenhouse gases are emitted [6]. Even though batteries have advanced technically over the past few years, fuel cells present various distinct advantages over traditional batteries. One might argue that traditional batteries can also provide a consistent power, so why is there a need for a highly expensive fuel cell? In spite of this being true, traditional batteries are not as compact and therefore are hard to transport.
This is due the fact that batteries have a weightenergy ratio of at least one-fourth of hydrogen fuel cells as illustrated in Figure 2. Furthermore, batteries die when its stored reactants are depleted. Even though rechargeable batteries solve this problem, their size still imposes a problem. Moreover, batteries require significantly more time to recharge than a fuel cell. Having fuel cells as a backup energy source is advantageous over backup batteries. Contrary to a battery, fuel cells stay in a working condition until their external fuel supply is depleted.
Fuel cells do not rely on stored energy [7]. Fuel cells have longer run-time, rapid charging capability, as well as significant weight reduction potential relative to batteries thus making them a superior product [8]. Among the various uses of fuel cells, they play a very crucial role in one part of military-allowing remote missions to be carried out off the grid for longer durations. Fuel cells can be utilized to power up the telecommunication devices and servers such as Terrestrial Trunked Radio (Tetra) networks used by special task teams and emergency responders [9].
In such circumstances, the device must be compact and dense in order to carry out stealth missions in a tactical fashion for a long time without requiring a replacement. Furthermore, stationary fuel cell systems can be used to keep the internals of vehicles online for much longer than batteries. Moreover, fuel cells have no moving parts; thus, they emit no noise when in use which could be of high value in stealth operations [11]. Presently, fossil fuels are used in regular bases and batteries are used where stealth is needed. Fuel cells triumph over both of these technologies due to its compactness and the ability to operate quietly.
Output energy from fuel cells, unlike batteries, does not decrease as their charge falls. Where a battery would provide an everdecreasing power output until it dies, a fuel cell can provide a consistent and reliable output throughout its use. Their easy-toreplace mechanism makes them even more superior compared to batteries. A fuel cell has a significant advantage over traditional battery in most fields of usage. When external energy sources are inaccessible or scarce in remote missions, fuel cells can prove to be beneficial by energizing the essential services vital for survival and the operation of the mission reliably.
A system using fuel cells can prove to emit less green house gases compared to fossil fuels. They hold a great potential in the field of transportation in the military, specifically, cargo planes. In spite of not having the power to handle all operations of flight, fuel cells are capable of providing enough energy to power the internal systems of the aircraft: lights, air conditioning, communication to control ground base, and computers systems [12]. Although running small internal systems of the aircraft might not appear to be a huge cost, it will surely decrease a fraction of the load off the main engines.
Even a small decrease in energy requirements from the main engines will have a huge impact on the annual fuel cost. Additionally, PEMFCs produce water vapor as an end product along with electrical energy, which can be easily condensed and used on the aircraft. A little over two dozen gallons of water can be produced from three 255-pound PEMFCS [12]. Carrying less water will greatly reduce the takeoff weight of the aircraft and thus increase fuel efficiency per flight. Abovementioned functioning can be achieved by electrolysis powered by renewable energy.
Using such a method will reduce greenhouse gases emitted as aircrafts use less fossil fuel. Aforementioned features of fuel cells have already been exploited in a different sector of the military. They have been used to provide electricity, heat, and water for a military dormitory located in the base Barksdale Air Force Base (AFB), LA. Systems were also set up and available to support critical operations for emergencies [11]. This proves the reliability of FCs as they are already being used at areas that highly sensitive to power outage, such as AFB.
Fuel cells can also be used to run surveillance devices for longer that can essentially provide a safer environment for militants to work. A mini prototype fuel cell system was implanted into AeroVironment’s Raven UAV. A flight time of an impressive three hours was achieved which is double that of the highest performing battery in similar conditions. Subsequently, the Naval Research Laboratory (NRL) Ion Tiger UAV achieved an unofficial record of 26 hours and 1 minute while carrying a fivepound payload.
Using these dense FCs would permit militants to use their spy or surveillance equipment for longer. This grants them with the ability to scan a larger radius of land without far exceeding the boundaries of the base that might potentially compromise their security. The next big milestone for this project would be to increase the fuel cell power to 15 kW and to increase the payload in hopes of achieving even longer flight time. (DoD document page 31. Right side) This proves that even if hydrogen is produced through fuel reforming, it can provide substantial safety measures to soldiers.
The various advantages of PEMFCs presented and outweighing their controversy with strong evidence demand this technology to be pursued to the maximum capability. The advantages and applications outweigh the disadvantages drastically. The single disadvantage discussed in controversy can be overcome easily by using electrolysis powered by renewable energy. The applications of fuel cells in the military sector are of too high a value for the technology to be deprived of development. Fuel
Ils are marginally superior to the current technology being used in remote missions. The controversy can be settled by looking at the facts presented prior. Additionally, using fuel cells in military transportation not only disproves the controversy, but also signifies that the reverse if true; using fuel cells in cargo planes actually has less carbon footprints compared to cargo planes not equipped with fuel cells. Moreover, using fuel cells in surveillance units provides militants with a safer working environment as it provides a longer operation time.
Hydrogen fuel cells offer various advantages such as their long run time, ability to produce consistent power, and the ability to be refueled much quicker. Currently, Department of Defense in the United States of America mainly uses diesel-fueled generators and battery-powered backup systems to provide essential energy for its operational systems. However, the Defense Science Board Task Force has come to a conclusion that these methods of power delivery are lacking. [13] So the research for a better source of energy must begin now.
