To me, this device looks far more sensitive to any movement as...

To me, this device looks far more sensitive to any movement as compared to those that operate hydraulically.

It would seem that it could generate electricity over the full range of movement that the platform is subjected to.

This is only a guess but I am thinking hydraulically operated power take off systems have a minimum sea state in which they will produce electricity.

Perhaps they could put a mast on the platform to accentuate the movement and increase output.