I came across a website www.lhup.edu which shows how and why many models will not work. Initially i read and left the webpage but later while thinking i thought what if we can achieve the position as mentioned in the website Buoyancy motor #1
This seems to be impossible but what if we can keep the liquid in "j" shape one in the colour image will it be able to generate electricity
reference:
http://jshapeliquid.blogspot.in/
https://www.lhup.edu/~dsimanek/museum/unwork.htm#buoy1