One area of North Carolina’s Outer Banks designated as National Seashore

One of the most effective arguments against offshore energy developments (of many types – not just offshore wind) is the negative impact to the local viewshed. In North Carolina in particular, the Outer Banks are dominated by land designated as ‘National Seashore,’ and therefore under much greater effective protection from any sort of development than lands owned and inhabited privately by local residents. The National Park Service, the government office that manages federal lands like National Parks, Forests, and Seashores, recommends any offshore ocean energy development be at least 20 – 30 nautical miles (about 25-35 miles) away from any oceanfront national parkland (see Visualization Study conducted by BOEM). This removes any injurious impact to a landscape otherwise bereft of human development, both during the daytime as well as at nighttime due to the lights required for FAA regulations.

As current technology requires a seafloor mooring for many types of ocean energy conversion methods, any development is usually restricted to the continental shelf (in North Carolina, the shelf is around 50 miles wide). You can imagine these two qualifications in conjunction with each other greatly restrict any proposed projects off of North Carolina’s coast, in effect cutting any potential areas in half. It’s easy to say that the arguments for maintaining a coastal viewscape are superficial, or inconsequential in nature. But it’s also important to remember that local residents are the ones who will have to live with these projects, and even transient tourists, who might not live in these areas, still find value in the unobstructed view of the neighboring ocean. A vehement lust for taking any energy wherever we can get it is what got us into this mess in the first place.

It follows that in order to ameliorate these issues, we must either advance technology in floating turbines (and other methods capable of deployment further away from shore), or make these technologies invisible. While there is significant research being done on creating a feasible floating turbine design, I find the other option a little interesting as well. No, I’m not talking about actually turning a turbine invisible, though this guy has thought about doing just that. But as marine scientists know, the energy stored in oceans is not just tangible at the surface. Wind energy is transferred to the ocean creating surface waves, but we also know that these surface waves – and other gravity waves – are not restricted to surface motion. Their energy is continuously transferred through the water column and in shallow water, often results in wave motion at the seafloor – an area ‘invisible’ to communities onshore.

Enter Reza Alam, and his UC Berkeley team. His research group is proposing a “seafloor carpet” that converts ocean waves into electrical energy in the same way that I have described other types of surface wave energy converters do. Mimicking the wave dampening effect of naturally occurring muddy seafloor, Alam’s device consists of a rubber sheet on top of hydraulic actuators. Rather than creating electrical energy onsite, the hydraulic actuators create hydraulic pressure which is then piped onshore where it undergoes conversion to electricity. This idea has the benefit of not obscuring any viewsheds, as well as not posing a danger during stormy weather due to the buffer distance of water between the surface and the structure. Alam even says that the system works most efficiently during stormy seasons.

An artistic rendering of the proposed ‘seafloor carpet’ system.

In looking for energy alternatives to fossil fuels, there are several important lessons that need to be absorbed from both the scientific community as well as the economic and social groups involved. First, there is no one, easy answer. We have lots of good, and some fantastic ideas for creating cleaner energy systems for our world. But not one of these is the end all, be all of solutions. Like any successful financial investment, diversification is key. Second, the local communities, or “stakeholders” as BOEM likes to call them, should have final say-so in any potential project. No matter their unfounded opinions or evident biases, they are the ones who will have to live with whatever consequences this development ends up creating. Long after the area has been abandoned after a less than fruitful project, they will be cleaning up the mess (see: Appalachia and coal industry). It is crucial that they have agency in what happens to their land. Lastly, considering the two previous lessons, we shouldn’t be lazy when it comes to innovation! Offshore wind projects are undoubtedly perfect for certain areas. But for locations where maybe there are some downfalls, ideas like a ‘seafloor carpet’ might be the best of both worlds. The key to establishing renewable energy as a viable and beneficial alternative to fossil fuels will be to find a locally tailored solution in which every party can see a benefit.