How Effective is a Hydrogen Fuel Engine: MPG, Fuel Cells, Maintenance, and Cost

A hydrogen fuel engine is one of the new alternative fuels available in automobiles. Several states used this type of engine in buses due to the fact there are no tailpipe emissions which can greatly reduce air pollution. The buses also are able to consume less fuel than when compared to a traditional diesel or gasoline vehicle.

How Does it Work?

The hydrogen fuel cell works through chemical reactions. As long as there is fuel and oxygen for the fuel cell then it can produce electricity indefinitely. Normally the fuel is hydrogen and oxygen is provided from air. The main outputs of the cell are water and heat. Basically, pressurized hydrogen gas enters the anode side of the battery and is forced though a catalyst, which splits the hydrogen into protons and electrons. There is a proton exchange membrane that allows the protons through, but blocks the electrons. The electrons then travel through a circuit as electricity and can be used as power. When the electrons reach the cathode catalyst they combine with oxygen, which then binds with the hydrogen and forms water.

Energy Conversion

The fuel cell is much more efficient than compared to a normal gasoline fueled vehicle. About 80% of all possible energy can be converted into electricity and used by the vehicle for power. However this 80% just refers to the cell itself. When the cell is placed in an engine, then the efficiency drops to 64%. This 64% efficiency is still much better than a gasoline car. Gasoline fueled cars only have a 20% energy conversion rate. So in terms of mpg of hydrogen fuel, that is about 93 mpg. This is almost triple what many vehicles get on gasoline, around 35mpg. This is also much better gas mileage then other hybrid vehicles.


Ultimately the maintenance costs are much lower for hydrogen fuel cells because there are less moving parts. The less moving, the less friction that is produced, and it is friction that tends to damage vehicles and require maintenance. The fuel cell engine is also much lighter than traditional engines, which have less wear and tear and also decreases maintenance costs. Additionally there is less shaking when the car is on, which provides a much smoother and quieter driving experience.

Main Costs

The main cost comes in the initial investment, as fuel cells cost more to produce than a typical gasoline engine. Additionally, one fuel cell is not enough to power a car. Several stacks are needed. Currently, enough fuel cells to fill a small suitcase will completely power a vehicle. Another large cost is the actual transportation of hydrogen to suppliers and from production facilities. A hydrogen pipeline is much more expensive to build and maintain than a gas pipeline. There is also not a huge infrastructure available for hydrogen fuel cells, so besides the initial conversion of a car that is costly, may also include an at-home filling station if local hydrogen filling stations are not available. Also, even though maintenance on the vehicle is less, finding someone to do that maintenance may be a problem. There are plenty of repair mechanics for gasoline vehicles, but it is quite rare to find someone to maintain a hydrogen fuel cell vehicle.