What are radioisotope thermoelectric generators used for?

Radioisotope thermoelectric generators (RTGs) utilize the heat generated by the decay of radioactive isotopes to produce electricity. Because these devices are highly reliable, resistant to radiation, and capable of providing power over long periods, they are ideal for remote or unattended applications.12

Common uses for RTGs include:

• Space Exploration: They serve as a primary power source for spacecraft, particularly deep-space probes that travel far from the Sun where solar power is less effective.13
• Remote Monitoring: They provide electricity for isolated weather stations and deep-ocean data collection systems.1
• Communication and Warning Systems: They are used to power various remote warning and communications infrastructure.1
• Medical Technology: Historically, low-power versions were developed to power cardiac pacemakers.1

Generally, these generators operate within a power range of ${10}^{-6}$ to 100 watts.1