Windmills at sea

The winds of change are blowing fast over the world's oceans, and energy developers intend to harness them with offshore wind parks which produces a lot more energy than windmills on land. With more energy production, it becomes much cheaper to produce these windmills. In these times of climate change and an increasing demand for oil, this new energy solution makes perfect sense. Offshore windmills will provide a reasonable, environmentally-friendly and economically feasible alternative to standard energy generation processes.
The windmills would use tethered systems, similar to the ones used in oil rigs, that holds a 200 meter tall steel tube with an attached turbine and three 60-meter-long blades. The windmills could then be located 50-100 miles off shore, and with a depth of up to 500 meters. With the further from shore you go, the wind speeds increase dramatically to have the ability to produce 5.0 megawatts (MW), compared to 1.5 MW for onshore units and help satisfy our energy needs without being eyesores from land.
Newer, float-able windmills are estimated to be a third of what it costs to install current offshore tower windmills. Another advantage of using floating platforms is that the windmills could be moved around if they were needed in areas that required more power.