Andy Burns wrote:
Nightjar wrote:

In the 1970s, the Soviet Union built a series of remote lighthouses
along their northern coast, which ran off individual subcritical
reactors.

Yes, but with enough juice for a light bulb ...

https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Terrestrial


These were used in desert regions where solar panels with back
up batteries suffered from dust problems. I went to a lecture on them in
the 60s. Also used in spacecraft for deep space long journeys where
solar panels could not generate enough power.