A device that generates an electrical current by converting the chemical energy of fuel (for example, hydrogen) directly into electrical energy. Fuel cells rely on a chemical reaction. Therefore, they emit less carbon than fossil fuel based technologies, such as coal fired plants. In addition to being cleaner and more environmentally friendly, fuel cells are energy efficient and fuel flexible.

According to the Department of Energy (DOE), fuel cells have the potential to replace the internal combustion engine in vehicles and provide power in stationary and portable power applications. Despite these demonstrated benefits, there are many reasons why fuel cells are not yet widely used, including: