Why does it need to be 25 nm away? Why not build them closer to shore? A half mile offset from dwellings is considered generous in the Midwest, and the wind is pretty steady along parts of that coast.
It doesn't necessarily. My point is that it's a more challenging environment than on the east coast, and I'm not aware of any offshore wind projects in planning stages on the west coast. Perhaps there are some (but I wouldn't be surprised if the intention is floating turbines).
The offshore turbines tend to dwarf anything installed in the midwest. It's not really a great comparison for proximity.
Logistically the west coast is challenging too because at this point the US offshore wind industry is pretty immature, and it's European companies winning the contracts to build and install the foundations. Jacket foundations could be constructed in the Gulf but the larger monopile foundations are probably going to come from Europe. The east coast seems easier to tackle first.
