Wave power

Q: You talk about geothermal, solar and wind, but you never mention wave power. Got an opinion? – G.T.

A: I think wave power is cute – it looks like a power source, only smaller... No really, these buoys do generate power. But like solar and wind, they need a whole lot of space and a whole lot of expensive investment to approach anything like a real power plant.

Wave power extracts energy from the ocean using buoys. The rise and fall of the buoys on the ocean's surface generates a current, which runs by a cable to a power station on land.

It takes 30 acres of buoys to generate 1 megawatt. The U.S. has peak production capacity of about 1,000 gigawatts of electricity. A gigawatt is 1,000 megawatts. Therefore, to generate one one-thousandth (0.001) of the energy we need, you'd have to cover almost 50 square miles of ocean.

According to Unenergy, a blog that promotes alternative energy, geothermal is the cheapest alternative energy. A new geothermal plant will cost about $6.2 million per megawatt to build. A wind farm comes in around $6.75 million per megawatt. And a new solar plant runs about $7.9 million per megawatt.
Wave systems cost around $8.2 million per megawatt.


Compare that to a coal-fired power plant that can pull carbon dioxide out of its exhaust. It would cost about $2.9 million per megawatt to build. A new nuclear power plants costs about $3.75 million per megawatt.
So for coastal towns that want to supplement their existing power grids, wave power could be an expensive but "green" option. But it won't ever be a meaningful addition to the national power supply.