Could Future Cars Be Fueled by Hydrogen?
A century or so ago, the total number of vehicles available on Earth numbered a few thousand. But today, the situation has changed completely, with more than a billion cars being available—translating to one vehicle for every 7 individuals. Now, if you choose to think of Earth as a big gas station that has only been supplied with a limited amount of fuel, you will quickly realize that we are looking at a major problem down the road.
Peak Oil Point
Many modern geologists hold the opinion that Earth is soon headed to the ‘peak oil’ point. What this means is that in a few decades, gasoline supplies will fast decrease. If this comes to fruition, where will vehicles get their gas supplies from? At the moment, there exists only one viable short-term fix — enhanced fuel efficiency in existing automobiles.
But what about the long term? Manufacturers will need to start looking for ways to switch from diesel and gasoline engines to the use of electric fuel cells. These types of fuel cells are similar to batteries that have been powered using hydrogen gas that never go flat. The electric fuel cells are pollution free and silent. They also happen to be among the greenest and cleanest power sources that are yet to be manufactured.
Electric Fuel Cells — What Are They?
Are fuel cells everything they have been promised to be? Let us take a much closer look at the cells below and how they work.
There exist only two viable methods of powering a modern vehicle. Most automobiles running on today’s roads rely on the use of internal combustion engines for them to burn gasoline, produce heat, and be able to push the pistons up and down so as to drive the wheels and the transmission.
Electric vehicles function on a very different basis. Rather than use an engine, the cars rely on batteries. The purpose of these batteries is to feed power (electricity) to the motors that then directly drive the wheels. A hybrid car relies on both electric motors and internal-combustion engines. They, therefore, switch between the two power systems to meet the prevailing driving conditions. The fuel cells are like a mini-cross between battery power and internal-combustion engines. As is the case with internal combustion engines, the fuel cells generate power by relying on the fuel being supplied by a tank. But instead of the fuel being diesel or gasoline, the cars get to use pressurized hydrogen gas. However, unlike the case with engines, the fuel cells do not burn the pressurized hydrogen gas. The gas is chemically fused with oxygen obtained from the atmosphere to produce water. This is a process that closely resembles the activities that normally take place in a battery.
The end result of this process is that electricity ends up being released which is then used to power up the electric motors that can be used to drive the car. Here, the waste product happens to be pure water. This means that you can actually drink this water. As such, fuel cells can actually be thought of as batteries that will always keep running as they never go flat. Rather than slowly drain the chemicals that are in them, as happens with normal batteries, the fuel cells instead get to run on a steady hydrogen supply. The implication being that they will continue generating electricity as long as the tanks are full.
Features of a Fuel Cell
The activities taking part in this type of cell are known as an electrochemical response. The reaction is chemical because it involves the combination of two chemicals. Nonetheless, this reaction is also electrical in that electricity gets to be produced as the reaction progresses. You should note that fuel cells tend to have three main components, as is the case with modern batteries. They have positively charged terminals, negatively charged terminals, and an electrolyt e— which is the separating chemical.
The electrolyte has to ensure that the positive and the negative terminals remain apart at all times. The fuel produced by these reactions is often referred to as PEM fuel. There are different beliefs on what PEM stands for, with many claiming that it means proton exchange membrane while others claim that it stands for polymer exchange membrane.
Regardless of what you call it, the one thing you need to know is that the cell will keep running as long as it is supplied with oxygen and hydrogen. Given the fact that there is plenty of oxygen available in the atmosphere, it means that the sole limiting factor here is the total amount of hydrogen that is readily available in the vehicle’s tank.
Fuel Cell Stacks
One fuel cell is able to generate as much electricity as your ordinary single dry-cell battery — which is not enough to power up a simple laptop, leave alone a modern vehicle. This is the reason why fuel cells that have been designed for automobiles make use of fuel stacks that have been linked together in a series. The total electricity produced by the fuel stacks is equivalent to the available number of fuel cells, multiplied by the power produced by each fuel cell.
Fuel Cell Types
PEM fuel cells, which are in some cases referred to as PEMFCs are currently ranked very highly by many engineers when it comes to powering cars. However, you should note that they are not the only design currently available.
For instance, there is the Spacecraft design which has been said to be a bit primitive, in that it uses the alkaline fuel cell. The solid-oxide fuel cell is said to generate more power compared to the AFC. On the other hand, the microbial fuel cell happens to come with an extra feature — it uses a bacterial tank to digest organic matter as well as sugar in order to produce either hydrogen gas or an electric current.
An alternative would be to use a solar panel that has been placed on the vehicle’s roof. The panel would use the electricity supplied by the sun to split water into oxygen and hydrogen gases through the use of an electrolyzer. Once generated, the gases would, later on, be combined inside a fuel cell so that they can start producing electricity.
Using this option, as opposed to relying on the energy provided by the sun directly is beneficial, in that it becomes easier for you to shore up your hydrogen reserves during the day. These reserves can then be used to drive the fuel cells in the evening when there is no sun.
The Problem with Hydrogen
As much as relying on hydrogen seems to be beneficial, there does exist a problem with this solution. Hydrogen production through electrolysis uses energy, and lots of it. This is because electricity is required for the water to be split up. If normal solar cells are used to provide this electricity, they may prove to be about ten percent efficient.
This is as compared to an electrolyzer whose efficiency stands at seventy-five percent. The implication here is that solar panels will provide an overall efficiency of about seven point five percent. All things considered, this is a very poor start. Energy is also needed to transport the hydrogen as well as compress it, for it to be turned into liquid form from its gaseous state. This helps make it easier for vehicles to carry it in their tanks. This in itself poses another problem. This is primarily based on the fact that hydrogen’s density is only about a 5th of the normal gasoline.
What does this mean for you as a vehicle owner? It is that you will need 5 times more to travel as far as you would have gone with gasoline. And this is based on the assumption that your hydrogen-based vehicle is as heavy as the gasoline one —something that is not always true, taking into consideration that gasoline-based cars require heavier transmissions and engines.
Another problem comes in the form of storage. It is more difficult to store hydrogen for longer durations due to the fact that its small molecules can easily leak from many containers, and considering that hydrogen is easily flammable, even a tiny leak can cause a very bad explosion.
Hydrogen Plus Points
Although hydrogen seems to have very many disadvantages, its proponents also state that it also has its advantages. For instance, charging a battery powered vehicle can take anything from thirty minutes to a whole night, but it only takes 5 minutes to refuel a hydrogen-based automobile. Another bone of contention has been on the distance that can be covered by a single charge. Many manufacturers today claim that their vehicles can travel hundreds of kilometers on one-charge only, but the reality is that the range is likely to suffer as the battery starts to depreciate. On the other hand, fuel cell cars offer the same range as their battery-powered counterparts, but their range does not decrease with age. And where battery technology is favored in smaller vehicles, fuel cells can work well for both trucks and heavy commercial vehicles.
So Could future Cars Run on Hydrogen?
In short, yes. As seen above, and based on the current experiments being carried out in Japan and the United States by top corporations such as Honda Motor Company, Ltd., Nissan Motor Company, Ltd., and Toyota Motor Corporation, it is probably only a matter of time before they become a fixture on our roads.