Electric vehicles and hybrid electric vehicles which are able to be charged from mains power have potential to greatly increase the demand for base-load power from grid systems. Development of these depends critically on battery technology.
Radioisotope power sources have been an important source of energy in space since 1961. Fission power sources have been used mainly by Russia, but new and more powerful designs are under development in the USA.
Some 140 ships are powered by more than 180 small nuclear reactors. Most are submarines, but they range from icebreakers to aircraft carriers. In future, constraints on fossil fuel use in transport may bring marine nuclear propulsion into more widespread use.
Hydrogen is widely seen as a future transport fuel. Nuclear energy can be used to make hydrogen electrolytically, and in the future high-temperature reactors are likely to be used to make it thermochemically.