How does energy from an ocean wave power stuff in a house?

The density of the energy that is transported under the waves under the ocean surface is about five times higher compared to the wind energy 20 meter (about 65 feet) above.  In other words, the amount of energy in a single wave is very high. However it turns out that when they tried to make the high power of the waves to power things in a house it only made it past the first few stages there were very few that made it to some stages. This started taking place in around 2001. hope this helped if not let me know and i could explain more:)