Rivers were used to turn watermills and the Romans even used geothermal water for heating. Until the middle of the 18th century renewable sources of energy were the only forms of energy available, but then, with the advent of the Industrial Revolution, fossil fuels began to be exploited.
The Sidereal Zodiac is the position of the sun referenced against the star background, as a measure of the flow of time. The framework for the star background is the constellations the sun passes in front of. This is the one astronomers use.
That's nothing new. People have known this for centuries.. The sidereal zodiac is the zodiac that's changing. If indeed you follow the sidereal zodiac, your sign may change. But CNN makes the point that if you follow your zodiac sign and you're a westerner, you likely used the tropical zodiac. For you it's status quo.