Currently, most of the energy demand in the world is met by fossil and nuclear power plants. A small part is drawn from renewable energy technologies such as wind, solar, fuel cell, biomass and geothermal energy [1] and [2]. Wind energy, solar energy and fuel cells have experienced a remarkably rapid growth in the past ten years [3], [4] and [5] because they are pollution-free sources of power. Additionally, they generate power near the load centres, which eliminates the need to run high-voltage transmission lines through rural and urban landscapes.
The cost of solar photovoltaic and fuel cell electricity is still high [6], [7] and [8]. Nevertheless, with ongoing research, development and utilization of these technologies around the world, the costs of solar cells and fuel cell energy are expected to fall in the next few years. As for solar cell and fuel cell electricity producers, they now sell power freely to end-users through truly open access to the transmission lines. For this reason, they are likely to benefit as much as other producers of electricity. Another benefit in their favour is that the cost of renewable energy falls as technology advances, whereas the cost of electricity from conventional power plants rises with inflation. The difference in their trends indicates that hydrogen and solar power will be more advantageous in future.
In the near future, the utility power system at a large scale will be supplied by renewable energy sources and storage device(s), i.e., hybrid energy systems, in order to increase their reliability and make them more effective. The specific properties of fuel cells and solar cells are as follows: