Question:
What benefits do fuel cells offer?
One of the best characteristics of fuel cells is that they are a very clean energy source since the cell reaction with hydrogen and oxygen exhausts only water (H20) and heat. Also, compared with internal combustion engines, they have the potential to generate power very efficiently (see figure 1).
No matter what the type of fuel cell, we can convert at least 40% of the energy stored in the fuel to electricity. With alkaline cells that use pure hydrogen, or high-temperature molten carbonate and solid oxide cells, we can even obtain 45-60% efficiencies. But especially with high temperature types, we can use the heat produced by the reaction to drive a turbine, and achieve 65-75% efficiency in power generation. In this manner, waste heat from large area fuel cells can be reused for power generation, and waste heat from small area cells can be used for heat sources in homes. In other words, we can get more than 1.5 times the energy from a fuel that we have been able to obtain up to now (see figure 2).
Figure 2 Fuel Cell Types and Characteristics
