The correct option is C Its efficiency is less then conventional methods
In general, the chemical energy (heat of combustion) of fossil fuels (coal, gas, or oil) is first used for converting water into high pressure steam and then used to run a turbine to produce electricity.
In fuel cell, the chemical energy of combustion of fuels like H2, CH4,CH3OH etc. are directly coverted into electrical energy.
Advantages of Fuel cell:
1. They offer high energy conversions (almost 70%) compared to thermal plants whose efficiency is about 40%.
2. These cells have high energy density.
3. These cells use inexpensive fuels.
4. These cells are pollution free.
Fuel cells are used for providing electrical power in the
Apollo space program. The water vapour produced during the
reaction were condensed and added to the drinking water supply for the astronauts.