Wind power is a renewable source of energy that can reduce carbon and other toxic emissions. Land-based wind farms began production in the U.S. started the 1980s, and in the last 30 years, have significantly grown, not just in the number of them, but also in the size of each individual turbine, according to Alexis C. Madrigal from The Atlantic. As of 2011, the Roscoe Wind Farm in west Texas is the largest land wind farm in the U.S. It has turbines taller than the Statue of Liberty and can produce hundreds of megawatts, which is comparable to many fossil fuel facilities.
Moving turbines to the water where wind is more robust and consistent began in the 1990s in Denmark. Since then, the trend has grown immensely throughout Europe, and in July 2015, the first U.S offshore wind farm started being built off the coast of Rhode Island. The Block Island Wind Farm is being built by Deepwater Wind and has the potential to produce 30 megawatts of energy.
"We know the world is watching closely what we do here, and we're incredibly proud to be at the forefront of a new American clean-tech industry launching right here in the Ocean State," Deepwater Wind CEO Jeffrey Grybowski said in Eco Magazine.
Wind energy's potential on a large scale
Wind energy is typically calculated in gigawatts (GW). One GW of wind power has the potential to power between 225,000 to 300,000 average U.S. homes annually. According to the data collected by the Bureau of Ocean Energy Management, the East and West Coasts of the United States are the best locations, besides the Midwest, to harness wind power for electrical energy. In the U.S., over 53 percent of people live in coastal regions. Wind resources in these areas have the potential to supply a renewable, clean source of energy for thousands of homes.
The potential energy produced by wind turbines is directly proportional to the cube of wind speed. This means that an average increase of 1-2 mph in wind speed can produce up to 50 percent more electrical energy. The National Renewable Energy Laboratory (NREL) has developed maps of average wind speeds across the United States. It determined that although the Pacific Coastline has higher wind speeds, the Atlantic Coastline, Gulf of Mexico and the Great Lakes have more potential for successful wind turbines because of shallower waters.
"Building wind turbines on preexisting aquatic ecosystems can have negative impacts."
The effects of offshore wind turbines on aquatic ecosystems
Wind power is a wonderful source of renewable energy that has the potential to greatly decrease toxic emissions in the atmosphere. However, building wind turbines on preexisting aquatic ecosystems can have major negative impacts on many marine species. An article published in Aquatic Biosystems has determined that there are six major environmental concerns when developing an offshore wind farm. These include: increased noise pollution, risks of collisions, alterations to benthic and pelagic habitats, changes to food webs and an increase in pollution from vessel travel for maintenance or containments from the seabed during construction. Currently there are over 69 offshore wind farms in Europe; however there are still very few studies to determine the long-term impacts on both vertebrate and invertebrate marine species.
The construction phase and the activities involved with the pile driving will likely impact oceanic ecosystems the most. Currently, pile driving is the most common technique to secure the turbine foundation into the sea floor, although other techniques are being developed and tested for a smaller impact on marine organisms. The biggest concern with pile driving is sounds during construction. These disruptions could potentially cause permanent hearing damage as well as other social impacts on organisms that live in groups. There is also a risk to many of the marine mammals being displaced due to the increase in noise levels as well as getting injured by the larger number of vessels involved in the construction of the turbines.
After the construction phase, the noise level will no longer be impactful on the marine mammals or fish. However, ornithologists are concerned with the mortality rates of sea birds due to collisions into moving turbine blades. Offshore wind turbines also may affect the migration patterns of different species of sea birds as well as those that breed and feed in the vicinity of the wind farm.
Potential for positive environmental impact
Offshore wind farms are still in their infancy, and because of that, it is still unknown how they will impact the marine ecosystems in the shallow waters where they are being built. However, they do have the potential for positive growth. For example, the underwater structures may act as artificial reefs, providing habitats for many invertebrate benthic marine organisms such as coral and bivalves. Consequently, this may cause an increase in the population density of the organisms found in reefs, therefore increasing the number of fish and other marine mammals that feed on them. Wind turbines may also cause a sheltering effect in that the areas around them would no longer be accessed by boats. This in turn may create small-scale marine reserves.
To make the development of offshore wind farms successful, it will be extremely important for environmental consultants, water quality laboratories and aquatic ecological consulting services to work together with the Department of Energy, local government officials and the offshore wind farm developer to leave the smallest environmental impact possible. It is very important that officials collect data before, during and after construction of the offshore wind farm to monitor population densities, water quality and marine habitats. Research needs to be done to best understand the responses of marine species to offshore wind farm construction and operation, as well as the long-term impacts on these populations.