Waves are extremely strong
Waves can lift heavy ships, break thick dams and eat into the high cliffs along the coast.
There is much energy in the waves, and about 70% of the earth's surface is covered by ocean, so there is plenty space for them.
Wave energy can be utilized in wave power. It requires great technical facility. Wave powers are difficult to build because they must not be too heavy and expensive, but they must also withstand the extreme storms.
The energy content of waves varies from place to place. There is much more power in the waves at Hawaii than Hornbaek.
Wave energy can be "harvested" far out at the sea or close to the coast. In Denmark must one has to be far out on the sea because it only slowly becomes deep enough for large waves.
In Denmark the use of wave energy is still experimental.