Fuel Cells Pros and Cons

A fuel cell generates electric current through a source fuel. So let’s dig into fuel cells: pros and cons. Keep reading to also know its uses in industrial applications.

“Energy can neither be created nor destroyed. It can only be converted from one form to another” is what the law of thermodynamics states. Well, this rule is the Bible for most of the appliances and equipments used in commercial and industrial applications daily. But when it comes to converting an energy without polluting the environment, fuel cells are the most effective solution. So what is a fuel cell after all? One can term it as an electrochemical cell which derives electric current by converting chemical energy (from a source fuel) into electrical energy. But how is it different from other cells of the batteries which also do the same process? The difference lies in the utilization of the sources that generate the electricity.

Normal battery cells use metallic compounds like zinc, manganese and lithium. So once the chemical reaction is over, the battery life reduces and over a period of time, the battery either needs to be recharged or thrown away. But in a fuel cell, where sources like hydrogen and oxygen are used, the electrical energy is generated from the chemical process as long as the fuel supply is constant. The other difference is that the energy dissipated is again utilized as an additional source of fuel, thereby minimizing the wastage of energy. Now that we know something about these fuel cells, let’s understand fuel cells pros and cons along with its working.

How Does Fuel Cell Work?

Most of the fuel cells that are in use today, are hydrogen run fuel cells. So let’s understand how does hydrogen fuel work. The main purpose of a fuel cell is to convert the chemical energy derived from sources of fuel which is a combination of gases (like hydrogen, natural gas, gasoline, methanol etc.) and oxidants (like air and oxygen). It comprises of two electrodes: positively charged anode (which is the fuel) and negatively charged cathode (which is the oxidant). Both are separated by an ion conducting membrane. Say, the fuel is hydrogen and oxidant is oxygen. The chemical reaction takes place with the aid of electrolyte (potassium hydroxide), which is used for ionizing the anode where the hydrogen molecules are split into positive hydrogen ions and negatively charged electrons. The electrolyte further splits the direction of the ions and electrons, with the electrons traveling through an external circuit to cathode, thereby generating an electric current. Meanwhile the positive hydrogen ions on reacting with the oxidant (oxygen) at cathode forms water. So when many fuel cells are stacked, the surface area of each cell signifies current and the number of cells aggregated becomes the voltage. The electric power generated is the product of voltage and electric current. So this is how a fuel cell works. Now let’s see the pros and con of fuel cells.

Pros And Cons of Fuel Cells

Pros

• No recharging is required as the fuel requirements are simple. Hence no time loss is incurred.
• Constant power can be generated even in remote locations as long as there is an uninterrupted supply of fuel and oxidant.
• Fuel cells exhibit maximum efficiency even at low power levels. Practically, their efficiency is as high as 60%.
• Fuel cells do not pollute the environment. This is one of the major advantages offered by fuel cells. The only by product that is generated is water which is again a useful source of fuel.
• Fuel cells unlike their rivals – batteries (that run on internal combustion), are small and compact thereby fitting conveniently in systems (like power inverters and fuel reformers) which have space constraints.
• Unlike the sound pollution created by batteries used in vehicles and other industrial applications, fuel cells do not create any noise. Pertaining to this attribute and the heightened efficiency they offer, fuel cells are very much in use in electrical systems in residential areas and in automotive applications. Hydrogen powered cars are a good example of application of fuel cells.

Cons

• Fuel cells are quite expensive. A fuel cell system for gasoline powered vehicles approximately costs about USD 35-USD 73 per kilowatt. Also platinum which is an excellent electrolyte, used in fuel cells is a costly metal. There is an ongoing research to find an economical substitute for it.
• Fuel cells are sensitive to variations in temperature. The polymer exchange membranes used in fuel cells cannot operate at a temperature greater than 100 °C. Tolerance to this temperature is a requisite for a fuel cell in order to increase the tolerance to impurities in the fuel cell. So durability is a factor which needs to be worked upon for fuel cells as currently, they tend to degrade when the operating temperatures rise.
• The major issue with fuel cells is the infrastructure involved in making them. The regular fuel cells run on hydrogen. So the infrastructure involved in hydrogen generation plants, fueling stations, pipelines and truck transport are a way too complex and costly.
• Another hassle faced in fuel cells is the storage. Fuel cell vehicles are definitely environment friendly but the parameters like hydrogen storage, vehicle weight, costs incurred in vehicle infrastructure and safety measures are still being worked upon. Also the fuel supply has to be replenished continuously for a fuel cell to work.

Fuel Cells: Uses Some of the fuel cells worth considering are alkaline fuel cells, molten carbonate fuel cells and proton exchange membrane fuel cells. Fuel cells are of great use in aerospace applications. Fuel cells are also used in hybrid applications for providing base power load leveling and regenerative braking that involves batteries and booster capacitors. With a lot of ongoing research and development, fuel cells will find a laudable place in automotive applications. Although this avenue has been tried (Eg: hydrogen cars

), it is costly. So there is a research on how the costs can be cut down. Currently prototypes of fuel cells which are fueled by methanol are being studied if they could be used for mobile phone and computer applications.

Hope this article on fuel cells pros and cons was clear and concise. Fuel cells are definitely a better alternative to normal battery cells to sustain a pollution free environment. They are the nearly perfect solution for global warming and greenhouse gas emission problems.