system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are wave farms and other sea-powered stations so uncommon and experimental, compared to other renawable sources of energy?
gpt
Waves are pretty hard to harness energy from. Most of our systems of producing power involve spinning turbines. This is a nice and fairly straightforward way to make electricity. The spinning gives a smooth flow of power. Waves go up and down, so now you need to convert that up and down motion to rotary motion, which isn't particularly hard, but it's a pain in the neck. Plus the wave height and position will vary a lot with weather and tides. 

The ocean is also a terrible environment to build anything, especially complex moving machinery. For one, salt water is extremely corrosive to most metals. Your options then are very expensive alloys of stainless steel, or constant maintenance and repairs. And then there's debris and ocean life to worry about getting into your machines. And ocean front property tends to be pretty expensive. It's very desirable for housing if it's pretty, or for ports if it's not. For all that time, effort,  and money, you could put windmills in fields or solar panels on roofs.