On-demand ocean hydropower

If solar or wind energy don’t float your boat, maybe generating power from waves will be more up your oceanic alley.

In an effort to create even more predictability from the ocean, Dartmouth Wave Energy, a British company has developed an energy converter called the Searaser, which is making waves. Literally.

The machine attaches to the ocean floor by a movable tether, which allows it to float up and down. Pumping is made possible by the motion of waves lifting the device as it rises and falls. This water is either pumped to shore to drive a turbine at sea level (the on-demand ocean hydropower part), or up a hill where it could be held in a reservoir and used as needed to drive a hydroelectric turbine.

So far the prototype has successfully pumped water up a 160 foot hill and the company expects a full-sized version to be able to pump water up a 650 foot hill and have the capacity to generate 0.25 MW per device. 

Looks like you would need  to corral a school of searasers to make this idea float.