Offshore wind farms, currently proposed or in development from the Gulf of Mexico to Massachusetts - including one massive proposal for the Great Lakes - could rescue America from Mideast oil energy dependency and provide enough energy to power the entire country from one renewable resource. The question is: who will rescue the fish and large mammals impacted by such proposals? That answer is still blowing in the wind.

In a November paper published in the Journal of Marine Systems, Norwegian meteorologist Goran Brostrom reports that winds blowing at as little as 11 miles per hour can be disrupted by large wind farms and cause downwind ocean upwelling. Brostrom's study presupposes wind turbines in about 300 feet of water, which is deeper than most offshore wind farms currently go, primarily because maintenance costs rise exponentially with each mile from shore.

The change may seem small (about 3 feet per day), and the wind farms have to be large - about 2 square miles - to produce the agitation and subsequent upwelling, but the same was once said about carbon dioxide emissions, which are currently generating climate change on a scale never anticipated a few decades ago. As one writer pointed out, everything affects everything.

At first glance, this potential upwelling in the lee of wind farms looks like it might actually be beneficial to marine ecosystems. By bringing nutrient-rich waters toward the surface, fish populations are enhanced. The phytoplankton, by being moved closer to the surface and the effects of sunlight, are also encouraged to spread, and the resultant "blooming" feeds more marine species.

Some blooms, like the notorious "red tide", are harmful, producing natural poisons like brevetoxin that kill marine species and birds and deplete the water of oxygen. Other plankton are beneficial, delivering oxygen to ocean waters through photosynthesis, fixing free carbon atoms to reduce the effects of climate change, and serving as part of the ocean's food chain by feeding krill, the staple food of some species of whale. Wind farms are fairly common in Europe, notably Denmark, the UK, Sweden and the Netherlands. In the United States, offshore wind is a dream and a hope, but nothing has actually been built. Because of the location of U.S. wind farms, the nation became the world's largest producer of energy from the wind in mid-2008, but all the installations are inland, primarily in Texas and California.

Offshore wind proposals are meeting opposition from environmentalists and the NIMBY factor. The Cape Wind project of Massachusetts - opposed by none other than Senator Edward Kennedy, whose home in Hyannis Port is about 8 miles from the proposed site - is composed of about 130 turbines likely tall enough to be visible from the shores of Cape Cod.

Other projects, by Bluewater Wind (Delaware), Galveston's offshore wind project for Texas,  and proposed offshore wind farms for Delaware, New Jersey and New York, are finding slow going, even though the Interior Department's Minerals Management Service expects to finalize its proposed rule governing leasing of offshore acreage by the end of this year.

Environmentalist's concerns revolve around aquatic inhabitants, as well as birds and bats. Though studies have shown the impact on birds to be much less than supposed a few years ago, there is abundant evidence that the drop in air pressure behind wind turbine blades does kill bats, albeit without impact. Another concern is that wind turbines may have an effect on such sea-oriented birds as whooping cranes, either by interfering with migration patterns or directly. 

Why offshore wind in the first place? It's not like there isn't plenty of land in the U.S. The first answer is, again, the NIMBY factor. The second is that wind blows faster directly off the coasts of oceans than almost anywhere else, making wind energy more effective.

The subject of ocean currents is too complex to visit here, but you can study it yourself. Suffice to say, scientists, meteorologists and wind energy experts don't know yet what the real effects of wind turbines on ocean currents will be. Those in Europe (specifically Denmark) have only been around since 1991, and were small (at 5 megawatts) to begin with. There's no way to extrapolate the effects of 450 megawatts in 200 feet of water.

On a positive note, a paper written by marine biologist Gero Vella in 2002 suggests that wind farms may be a "fish magnet", since swarms of fish tend to cluster and feed near stationary objects. Additionally, Vella anticipates no adverse impacts from the noise and vibration of wind turbine towers, which may cause larger sea mammals like whales to avoid them but are not likely to cause physical damage.

I'm skeptical, given the recent reports on the effects of U.S. Navy sonar devices on whales, but willing to adopt a ‘wait and see' attitude. Vibrations are not sonar, and whales have been adapting to oil rigs - if not oil spills - for decades.

Related Reading:
Delaware's Offshore Wind Farm
New Energy Economy Emerging

Image Credit:
.Martin