This creates two problems when used in an internal combustion engine. First, a very large volume is needed to store enough hydrogen to give the vehicle adequate driving range. Second, the energy density of a mixture of hydrogen and air is reduced and therefore the power output. There are two main problems with a hydrogen internal combustion engine.
First of all, hydrogen isn't as energy dense as other fuels, which means it takes a lot of it to work a bit. Add to that the inherent inefficiency of a piston engine (at best, only about 30 percent of the fuel's energy is converted into forward motion), you get a recipe for disappointment. However, for industrial applications, the hydrogen fuel cell makes more sense for those who can afford the infrastructure needed to support it. The energy densities of hydrogen fuel cells and lithium-ion batteries are very similar, making them great options for busy operations that need equipment that lasts a full shift.
Hydrogen energy was popular in the 1990s and early 2000s, when many thought it would start a clean energy revolution, but the imaginary new world of hydrogen energy never materialized. Hydrogen compression requires approximately 13% of the total energy content of hydrogen itself and, if it liquefies, it loses approximately 40%. The only truly carbon-free way to use hydrogen fuel cell energy is to use solar or wind energy (which cannot be accessed in some parts of the world) to generate electricity for the electrolysis process. When considering fuel cells to power your forklifts, make sure you understand all of their pros and cons.
Hydrogen fuel cells work through a chemical reaction of hydrogen gas with oxygen inside a fuel cell, which generates electricity and water as by-products. This includes a huge hydrogen storage tank because the energy density of hydrogen is substantially low compared to gasoline or diesel. Organizations must work with the local government and the fire department to obtain approval, in addition to worrying about the costs involved in supplying hydrogen gas or building an on-site plant to generate hydrogen gas. Compared to refueling a forklift truck that runs on propane, the hydrogen fuel cell refueling process has an advantage.
These high pressures in storage tanks can pose a health and safety risk and therefore great care must be taken when handling hydrogen as fuel in a vehicle. While it is true that hydrogen fuel cells do not emit harmful gases during operation, the same is not the case with the production process for producing hydrogen fuel. Because the energy density of hydrogen fuel cells is very high, equipment that runs on hydrogen can operate longer and with less frequent refueling than with a propane cylinder.