出典:Wikipedia
出典:『Wikipedia』 (2011/03/31 19:01 UTC 版)
Some Soviet era lighthouses and beacons were unique insofar as they were powered by radioisotope thermoelectric generators called the Beta-M. It was capable of generating 10 watts of electricity, almost enough to power a 12 watt fluorescent light bulb with light output equivalent to a 60 watt bulb. Those generators still in use are well past the point at which they should be retired, prompting environmental concerns.