The delta of the ice on stone speed between the sides is not dependent on the rotational speed but liner speed in relation to the rotational speed.
24 karma · joined August 28, 2014
The big empty box with water is an evaporative cooling tower used to cool the condenser side water.
The system in the article uses a pipe loop underground in place of an evaporator. This uses less water/energy but require a higher first cost and very specific location requirements which is why the cooling towers are still more popular.