# Energy lost to hydrogen fuel cell

So I have a question about an experiment we did in class.

We used a fan to blow air at a little wind turbine to generate electricity, we connected the turbine to a reversible PEM fuel cell to electrolyse water and generate some hydrogen and oxygen. We timed this process and recorded the average power output from the turbine to calculate the total energy produced by the turbine: 59.4 J.

For the second part of the experiment we passed the hydrogen through another PEM fuel cell which would power a little electric motor until all the hydrogen was consumed, and measured the power and time it ran for with the same device. Again, calculated the energy consumed and it gave only 2.4 J.

Which would make it seem like a lot of energy was lost, mainly I guess during the electrolysis, the fuel cell and I guess the motor itself. But can so much energy be lost during this process? If so, how?

• Mathsie, it was wise of your teacher to show you this demo. Regardless of how "elegant" a technology is, it should also demonstrate a high efficiency. Your experiment didn't come close to doing that, and I note that hydrogen fuel cell technology is talked about, but the efficiency of that technology is usually not talked about. Mar 27 at 22:48