July 30, 2004

Understanding Fuel Cells

I just read this article on a breakthrough in fuel cell development, and felt the need to clarify a few things.

Fuel cells do not "produce" energy, and they're not going to "make cumbersome power plants virtually obsolete". The breakthrough mentioned in the article does not say they have created a new power source for fuel cells, but that they have developed more efficient and cheaper fuel cells. There's a huge difference.

Consider how a normal battery works. When you pop a few Duracels into that stupid bunny, it's not magically producing energy. The battery is just releasing the energy stored in it into a more convenient form (electricity). Fuel cells are similiar, but instead of releasing energy stored in acid, they combine hydrogen and oxygen, which perform a chemical reaction, producing electricity and water. As long as the fuel cell is supplied with hydrogen and oxygen, you have power. However, once it uses up it's fuel, you'll need to replenish it.

So what's the problem? Pure hydrogen and Oxygen are not as easy to come by as you'd think. Natural gas and propane can be processed to generate them, or you can start with water, add electricy and reverse the chemical reaction mentioned above. Of course, if we had electricity available in the first place, we wouldn't need a fuel cell, would we? Because we need to add energy to isolate hydrogen, it should be considered more as a reusable, clean storage device than an energy source.

This is why hydrogen fuel cells will not neccessarily lead to a cleaner environment. We need energy to generate the hydrogen for the fuel cells. This is critical, because what are we using to generate that energy? We're burning fossil fuels. Natural gas, petrolium, and coal are the top choices today. Even if Detroit starts rolling off hydrogen powered cars tomorrow, and even if we magically alter our gas stations to deliver hydrogen, we'll still have environmental issues to deal with.

Once energy is captured using renewable, non-polluting resources (solar, wind, water, geothermal heat), hydrogen may well be the ideal way to store it. Until then, fuel cells can be part of the answer, but they are not the entire solution.


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