What is the main function of a fuel cell?

The primary function of a fuel cell is to produce electricity chemically by combining hydrogen and oxygen. This process occurs within the fuel cell through electrochemical reactions, where hydrogen molecules are split into protons and electrons. The electrons flow through an external circuit, creating electrical power, while the protons move through an electrolyte to the other side, where they recombine with oxygen to generate water as a byproduct. This clean and efficient method of generating electricity is one of the reasons fuel cells are considered a promising technology for sustainable energy systems.

In contrast, the other choices describe different technologies and functions. Generating heat for homes pertains to traditional heating systems rather than electricity generation. Storing solar energy relates to batteries or other energy storage methods, which capture energy for later use instead of generating electricity on-demand like a fuel cell. Lastly, filtering and purifying water is a task usually accomplished by water treatment systems, not fuel cells. Thus, the focus of fuel cells on the chemical production of electricity distinguishes them from these other options.