During radioactive decay allocated enormous amount of energy that can be converted into heat or electrical energy, and used as a power source where the use of conventional techniques uneconomic or impossible. This spacecraft, space probes, remote northern regions, and етс. Radioactive isotopes are used in such energy sources, must have certain properties, both in the technical parameters and economic indicators.
This paper discusses these energy sources and their possible application in various sectors of the economy.

Key words: radioisotope power sources, plutonium-238, uranium-232, a radioisotope thermoelectric generator, RTG.