New design for offshore wind farms

Despite some organisations opposition to them, it is obvious that wind farms are the future for energy production. The UK has renewable energy targets to meet, and now new designs are being drawn up for 'supersize' wind farms that maximise on energy production.
Thanet wind farm was opened last year as the world's biggest offshore wind farm, but even at 300 megawatts it is nowhere near enough for our country. It is hoped that Thanet alone can generate 1/3 of UK electricity by 2020, but this is a big ask.
Now there is a rush to draw up plans for even bigger offshore wind farms - not only designs, but fixing problems that current offshore wind farms have. Due to the strong wind and wave power at sea, the turbines break down often and are difficult to fix. At what point do they become cost-effective?
Watch this space...