"Offshore windfarms" refers to large groups of wind turbines that are installed in bodies of water, such as the ocean or lakes. They harness the power of wind to generate electricity. Full definition
This investment will allow The Crown Estate to gain firsthand knowledge of the challenges facing the development of wind turbines specialised for deep water marine deployment as the process of engaging industry to develop the next phase of offshore windfarms begins. (metaefficient.com)
The first offshore windfarm in the USA is being built off of Rhode Island's Block Island. (earthday.org)
I've been sitting on this for a long time, but California received its first offshore windfarm application last fall that sounds pretty interesting to me. (rabett.blogspot.ru)