Offshore Wind Farms

Sammy Gallagher
December 19, 2016

Submitted as coursework for PH240, Stanford University, Fall 2016

History of Wind Technology

Fig. 1: Offshore wind farm under maintenance. (Source: Wikimedia Commons)

Offshore wind farming was first used in Denmark in 1991. Since 1991 many countries have developed offshore wind farms in shallow waters off their shorelines. Wind farming, however, is nothing new. Humans have been utilizing the wind as source of energy for over 2000 years. Previously wind power has been harnessed by windmills to pump water, and today windmills are used to generate electricity. Countries are looking to increase the number of wind farms off the coast and are beginning to explore the technology's viability in deeper waters. [1]

How it Works

The technology surrounding wind turbines is specific to the placement of the wind turbine in the ocean. Monopiles are found to be the preferred foundation for wind turbines located in more shallow waters. The tower and the nacelle of the wind turbine are supported by a steel pile which is drilled into the seabed. The nacelle is the piece of the wind turbine that is mechanical, and in turn captures the energy of the wind. When wind is present, the nacelle faces the wind, generating electricity. Offshore wind turbines are much larger than onshore turbines. This is due to the increased strength of the wind on the water. Due to the increased size of the turbine, and the magnitude of the wind, the turbines are able to generate a much larger amount of energy than onshore turbines. All the power generated by the offshore wind turbines must be transported onshore to a power grid. Once arriving to the power grid the energy is then made into usable energy for electrical power use. [1]

Potential Setbacks

Like most modern technology, offshore wind farms are expensive to build and expensive to maintain. Their placement in the ocean, as shown in Fig. 1, adds further costs to maintenance. Off the east coast the water is much shallower than off the west coast, making the construction of the wind farms seemingly easier. Wind turbines can also be damaged by storms and high tides, posing an even greater cost to their maintenance. From a purely visual standpoint, many residents who live along the coastline have complained that the wind turbines are destroying their picture perfect ocean view. [2]


Wind turbines placed offshore are much more effective in generating energy than onshore wind turbines, for the wind reaches a much higher speed over the coast. It is also much more reliable that there will be wind offshore than there will be onshore. Many communities that sit along the coast have very high energy demands. This being known, installing offshore wind farms can effectively meet these needs and therefore lessen the need for onshore energy sources that may potentially be more harmful to the environment. The most important advantage of offshore wind farming lies in the fact that this source of energy is a renewable source of energy that does not further damage the environment. [2]

© Sammy Gallagher. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] "A National Offshore Wind Strategy: Creating an Offshore Wind Energy Industry in the United States," U.S. Office of Energy Efficiency and Renewable Energy, DOE/EE-07998, February 2011.

[2] W. Musial and B. Ram, "Large-Scale Offshore Wind Power in the United States," U.S. National Renewable Energy Laboratory, NREL/TP-500-40745, September 2010.