Hydrogen fuel cell kits are devices that generate electricity by splitting hydrogen into positively and negatively charged particles to power a circuit. This process creates by-products of water and heat, making it environmentally friendly.
Applying electricity to separate water into hydrogen and oxygen is a process known as electrolysis. A hydrogen fuel cell does the opposite and generates electricity by combining hydrogen and oxygen. Before the hydrogen and oxygen are combined, the fuel cell splits the hydrogen atoms into electrons and protons. Inside the fuel cell is a polymer film that lets positively charged protons through while blocking the negatively charged electrons. The positive side of the cell attracts the electrons, but they are blocked by the film and redirected through a circuit, creating current and generating electricity.
On their way through the circuit, the electrons reform with the protons, and the resulting hydrogen gas then combines with oxygen, creating water. As of 2015, hydrogen fuel cell kits are limited to concept cars or smaller kits used in radio-controlled vehicles and science experiments due to the cost of running a hydrogen fuel cell compared to a conventional engine. The energy produced by the hydrogen fuel cell is often less than the energy required to run it, although some kits use solar power to do the initial electrolysis to provide the source of hydrogen.