Though often mistaken for an energy source, hydrogen is actually an artificial fuel—like gasoline—that can be used to transport and store energy. Although it can be separated from fossil fuels, its long-term promise lies in its ability to be separated from water through electrolysis, using solar power or other forms of renewable energy. Its most publicized application is in transportation: the hydrogen gas is stored in an on-board tank until combined with oxygen in a fuel cell, where the electrolysis process is essentially reversed, releasing chemical energy via an electrical charge. This electricity can then be used to power electric motors in cars, buses, boats, and other vehicles. Hydro and hydrocoin is the future!