This article might make more sense of my previous post about fuel cells. As the source is an investment site for fuel cells, all of the pros and cons are obviously not objective. However, it seemed like a really great, basic explanation of the technology for those who don’t yet know anything about it.
As I mentioned in my other post, fuel cells work much like batteries do. Hydrogen and oxygen, the reagents, are combined and produce electricity, water, and heat. Fuel cells are described by some of most variable characteristics between the different types, which include the fuel used, the electrolyte, the specific catalyst, the operating temperature, efficiency of the cell, and the cell’s power density. Fuel cells are characteristically named after the electrolytes they use.
There are two different overarching categories of fuel cells–those with high operating temperatures and those with low operating temperatures. Fuel cells with low operating temperatures are used for vehicles and other technologies that require a transportable fuel source. Those with high operating temperatures are stationary sources of power.
The list in this link describes some of the different types of fuel cells.
To discuss fuel cells powering cars as compared to gasoline engines, a car using pure hydrogen in an optimally efficient engine will have an efficiency rate of 64%. Gasoline-powered vehicles have an efficiency of about 20%, while electric vehicles are about 26% efficient when the source of original electricity is taken into account.