Mr James Kwok explains the processes of the HIDRO+ World's First Sustainable Power Station.
By watching these several videos you'll glimpse the concepts.
Scientific Principles: Archimedes' Law, Pascal's Law
Archimedes' Law: Objects may displace fluids. If the mass of the displaced fluid is greater than the mass of the object, the object will float. If it is less, the object will sink. The density of an object is the mass of the object divided by its volume. Objects denser than the fluid they are in will sink, less dense objects will float.
Pascal's Law: Any pressure applied to a fluid is distributed uniformly throughout the fluid. This assumes that the fluids do not compress very much (like water).
Please be patient, it will magically rise Pascal's Law
Archimedes Gold Adventure Thermodynamics - all about Gases
When Archimedes stepped into a bath he noticed that the water level rose - he suddenly understood that the volume of water displaced must be equal to the volume of body submerged. This meant that the volume of irregular objects (like the King's gold crown) could be calculated with precision. He is said to have been so eager to share his realisation that he leapt out of his bathtub and ran through the streets of Syracuse naked shouting "Eureka Eureka!".
Classic Sumner Miller explains Archimedes' Principal Bernoulli's Principal
Archimedes was able to verify the Kings crown was solid gold (or not) without scratching it! Using this simple method requires no precision equipment: balance the crown against pure gold inside an empty fish tank, and then fill the tank with water to see if they are still balanced. Out of balance would indicate the crown was not solid gold.
THE ECOLOGY REVOLUTION 
THE ECOLOGY REVOLUTION 