They had to be fully autonomous, because they were situated hundreds and hundreds miles aways from any populated areas. After reviewing different ideas on how to make them work for a years without service and any external power supply, Soviet engineers decided to implement atomic energy to power up those structures. So, special lightweight small atomic reactors were produced in limited series to be delivered to the Polar Circle lands and to be installed on the lighthouses.
Searching for Doggerland. "For decades North Sea boatmen have been dragging up traces of a vanished world in their nets. Now archaeologists are asking a timely question: What happens to people as their homeland disappears beneath a rising tide?"
To a fisherman, all areas of the sea have names, just as a farmer will name his fields or streets have formal and informal names. For instance, there is the Witch's Ground, an area where the fishing is good, but the bottom is very rough and gear can easily be damaged or lost. Or if you're really unlucky, an undersea methane burst might make water less dense, and the sea could swallow your whole trawler. [more inside]