I was thinking of hurling up a lasso.
I agree that harnessing the motion of water due to lunar gravity is compelling. Water has a lot of mass. Trying to stop a large body of water from moving is a difficult task. There is literally the power of the moon in the oceans - this is the lasso.
I also agree that millions of small, cheap turbines would be more effective than few, huge jobbies. Connecting all the nodes to a grid sounds like a challenge though. Considering that 99.99994%* of the volume of Earths waters are empty, it's a good idea to put them (it?) to work.
Yes, I made this up.
