Our department’s chair and my adviser, Harvey Seim, talks to NPR’s Jared Brumbaugh about our research into the offshore wind energy potential in North Carolina. In the next few days, we will be able to launch two buoys that have been down for repairs for almost a year or so. Harvey describes some of the broader implications for the data these buoys collect, such as investigation into the offshore wind resource for electricity generation.
“The intent here is to take a closer look at what the offshore wind energy resource is like and to carefully document its structure to help define where and where not to consider deployment of offshore wind turbines.”
It might be your first instinct that a wind farm should be placed where the average wind speed is the highest. This instinct would be wrong. There is often very high variation in wind speeds, especially in coastal areas. Wind behavior follows daily and even seasonal cycles as well as responding to spontaneous weather changes. This could be disastrous for anyone attempting to use wind energy as their sole power source, or even for those being dependent in a small way on the power generated. If the wind dies down during the evening, when residents are all coming home and beginning to cook dinner, demand will quickly outpace supply.
One of the key factors in choosing a site for a wind energy farm, rather, is the consistency of the wind resource. As long as the wind at a particular location is constant, or at least predictable, it can be used for electricity generation. This way, utility management companies will be able to know how much power will be available at any given time, and whether they need to supplement it with energy from another source. The quantity available, therefore, becomes less important than the reliability. North Carolina seems like a place well suited for predictable winds due to its proximity to the Gulf Stream current, a strong Western Boundary Current that contributes to the strong wind speeds we typically see here. Our technology currently only allows for offshore wind development on the continental shelf, so a strong, steady current like the Gulf Stream so close to land could be just the combination we need.
The buoys mentioned in the interview above will give us a more accurate picture of how the wind behaves over the ocean as a function of time. This dimension is fairly unreported in many resource studies, as it requires long term observations over years or decades to determine the typical cycles associated with a specific place, rather than simply calculating an average. With the data obtained by the instruments on these buoys, we hope to answer a few questions that would be conducive to understanding whether North Carolina’s wind is fit for energy generation. Is it fairly steady? What speed would we expect to see? Does it display predictable characteristics during certain weather regimes? These buoys don’t just measure wind speeds and directions, they are also equipped to measure other physical properties of the ocean, such as temperature. We know that the temperature of the surface that wind is flowing over can affect the characteristics of the wind profile with height, so the launch of these buoys will hopefully provide some very interesting information that we can use to dissect the wind regimes in coastal North Carolina.