On earth the star Algol is named "Daemon" or "Devil's Eye". The messenger from Algol, who calls himself Algol, too, appears from an abandoned mining tunnel called "Devil's Tunnel". He looks and acts like a demon. So yeah, he's the devil. Hell branched out into heaven.
There is no doubt that this is a religious tale. The authors had no interest at all in politics, economy or technics. The story being told affects the whole globe, but it could very well play in a village. Robert Herne (Emil Jannings), his girlfriend, his wife, his two kids and his rival Peter Hell (Hans Adalbert Schlettow) with a son who is played by the same actor - these are the only main characters. In some scenes there are hundreds of extras, this hasn't been a low-budget movie, but "Algol" is just a family drama.
Expecting any kind of science fiction will most certainly lead to frustration. The whole world starts using the energy supplied by Herne's Algol machine. The only reason for that could be that it is incomparably cheap. But au contraire, it seems to be even more expensive than coal. Logic is another thing that shouldn't be expected. The whole mindset of this movie is very disconcerting.
"Algol" is an important part of cinematic history (kind of). A fantastically restored version exists. An introduction "How to enjoy Algol" might be a great idea, would be very helpful. Not using the label "Science Fiction" is a good first step.
