Transport today is mostly powered by fossil fuel. The reason for this is the ease of use and the existence of mature technologies harnessing this fuel source. Fossil fuels represent a concentrated, relatively compact source of energy. The drawbacks are that they are heavily polluting and rely on limited natural resources. There are many proposals to harness renewable forms of energy, to use fossil fuel more efficiently, or to use human power, or some hybrid of these, to move people and things.
The list below contains some forms of transport not in general use, but considered as possibilities in the future.
Transport portal
