Offshore wind farms are becoming part of America and the world's renewable energy landscape.

And now the Gulf of Maine is being considered a possible site for offshore wind development.

In this series of stories, you'll learn about this emerging technology and what it might mean for you, our coastal communities and the Gulf of Maine's natural environment.

In this story, part three of 11, we'll dive into how power makes its way from offshore wind energy arrays to the grid.

The Gulf of Maine is just one of many areas in the United States that is being looked at now for the development of offshore wind turbines.

There are five turbines off the coast of Rhode Island.

They sit in shallow water and are fixed directly to the ocean floor.

What's proposed in the Gulf of Maine is different.

The wind farm would be farther off shore and in deep water.

Those turbines are six megawatt machines.

The machines that will probably go into the Gulf of Maine will be probably twice as big, and they'll be on floating substructures.

The turbine spinning blades produce the power.

It is then gathered at a substation beneath the surface of the water.

From there, it's sent to shore through cables that are buried along the ocean floor.

The wind turbines are devices that extract kinetic energy out of the wind field and convert it to electricity, so that all that power gets gathered into one spot.

And then there's usually like 1 or 2 export cables.

That's a big cable about this big in diameter and it moves the power from the wind farm all the way to a point of interconnection that goes right into the land based grid.

And that's where the power gets used immediately.

There is existing infrastructure in Maine, New Hampshire and northeast Massachusetts, where there's transmission lines that run down close to the seashore.

And, could be potentially good, places to host injections from offshore wind.

Subsea power cables are not new.

They have been around for quite some time.

In fact, how we connect with Europe, the internet.

That's subsea cable.

How other areas like Martha's Vineyard and Nantucket get their power?

That subsea cable.

There are subsea cables already running underneath parts of the ocean.

A lot of times they're connecting, telecommunications.

So basically fiber optics versus electrical power.

But we have electrical power cables as well.

Most islands that have any kind of electricity that's generated from onshore sources, the chances are if it's far off that it's a subsea cable that's connecting that power to the mainland.

Projects that are being built now are anticipating that, though the cables might be quite long.

So maybe it's 50 miles or so that, that goes from the wind farm to the point of interconnection.

And if it gets long like that, then there's a technology shift that has to happen.

So you might start out if you're doing a project that's close to shore, you might be using a high voltage AC line which is alternating current.

But if you get further and further away, you have to shift to, direct current.

And the reason we do that is because the, the the losses along the cable are a lot less if you shift to high voltage DC, but it's more expensive.

So it's designed to transmit a lot of power long distances and, and with renewable energy, that's kind of what we need to do.

To keep the power cable from moving, it is either buried in the ocean floor or covered with a protective shield if it can't be buried.

So basically, the methods used and the type of armoring are all dependent on what type of habitats and sediment are found along the cable pathway.

So it's all site specific, all project specific.

And hopefully part of that, if it's submerging it, it's sinking into the substrate or putting it on in part as not only to protect the cable because that's the main function.

The side function is, is that hopefully you're reducing the electromagnetic fields that are coming off the cable and interacting with organisms above the substrate.

The Winds of Change in the Gulf of Maine series is a co-production of New Hampshire PBS and New Hampshire Sea Grant, with support from the University of New Hampshire.

Production funding was provided by the National Oceanic and Atmospheric Administration.