Introduction to Marine Energy (Text Version)

This is a text version of the Introduction to Marine Energy video.

[The NREL logo with the tagline "Transforming Energy" appears on screen. Additional text appears on screen: Marine Energy]

Aryana Nakhai, M.S., Researcher, National Renewable Energy Laboratory: When we think about the ocean we likely think of summertime and the beach, but what we may not immediately think about is the amount of potential there is for harnessing clean energy from the ocean. We call this marine energy. This video will cover what marine energy is, why it's important, types of marine energy resources and technologies, some considerations and challenges, and how researchers at NREL are actively working to address these challenges.

[Text on screen: What is marine energy?]

Where there are bodies of moving water there is energy, and the movement of water creates a vast amount of kinetic energy that can be harnessed to generate power. There are several marine energy resources that are distributed throughout the United States providing unique opportunities to different states and regions.

[A slide appears on screen titled "Technical Power Potential of U.S. Marine Energy Resources in Terawatt-hours per Year (TWh/year)." This includes wave, tidal, ocean current, and river resources. In all 50 U.S. states, there are 1800 TWh/year of potential marine energy resources. The infographic is broken down regionally to show TWh/year as follows: West Coast: 250; Contiguous United States: 430; East Coast: 115; Alaska: 1,100; and Hawaii: 250.]

Marine energy is a type of renewable energy derived from waves, tides, ocean currents, free-flowing rivers, and manmade channels.

[Text on screen: Why is marine energy important?]

So, what are some of the opportunities and benefits that marine energy can provide? Levi Kilcher is a water power researcher at the National Renewable Energy Laboratory.

Levi Kilcher, Ph.D., Senior Researcher, Water Power Technologies, The National Renewable Energy Laboratory: Marine energy is a super exciting technology because the resource is immense. Wave energy is a massive resource that exists along the entire US coastline, especially along the West Coast of the US. Tidal energy, which you can think of basically underwater wind turbines, is another technology that has a massive resource and has a lot to offer. And some of the things that make these technologies particularly exciting is they're very forecastable and predictable. We have satellites that are constantly measuring the waves, and so we can see the waves propagating across the ocean. We know where they're going to go and so we can plan for that energy to arrive on sort of weekly or daily time scales.

Marine energy, I think, is especially exciting because it complements other renewable energy sources in terms of the time of year and the time of day that energy can be provided. It's also right there on the coastline where a large fraction of our population lives. And so, these are just some of the examples of why marine energy is so exciting and so promising.

[Text on screen: Types of marine energy technologies]

Aryana Nakhai: You may be wondering how do marine energy technologies work? In a nutshell, marine energy devices capture energy from the movement of water and convert it to electricity. That electricity can be transferred via underwater power cables. There are lots of different marine energy technologies that are being developed to test and measure different ways to capture our ocean's massive amounts of energy.

The point absorber is one type of wave energy device that floats on the surface of the ocean like a buoy. The ocean waves make the buoy move up and down – or heave – in an oscillatory motion. This motion creates the relative motion needed to convert the energy in the waves into power.

This is an example of a tidal river or ocean current turbine. These turbines are similar to traditional wind turbines, but instead, the kinetic energy of the moving water is captured by spinning blades facing the direction of flow instead of wind. These devices are submerged and anchored at the bottom of a riverbed or ocean. As the current flows, it spins a turbine and generates power.

[Text on screen: What are some considerations and challenges of marine energy?]

Levi Kilcher: Marine energy technologies like wave and tidal energy are at a very early stage of technology development. Tidal energy is a little bit farther along. We're starting to see successful demonstration projects of single devices and we're at the point now where we're ready to scale that up to larger arrays of devices, whereas wave energy is at a much earlier stage. We're still testing single devices, trying different types of concepts, and really just trying to figure out what's going to work. The energy, once you have a device in the water, is free. But building that device, operating it, and maintaining it, all that costs money. And so, in marine energy we have these big questions about how we're going to get these costs down because working in the ocean is an extremely challenging place. And you also couple that with wanting to take care of the environmental impacts of your technology. You don't want your technology to have unintended negative consequences on the environment.

[Text on screen: How is NREL addressing these challenges?]

Aryana Nakhai: The National Renewable Energy Laboratory performs research and development as well as economic analysis to inform future research and provide data to accelerate the development of marine energy. NREL researchers collaborate closely with the wave and current energy communities to provide expertise in computer modeling and simulation, laboratory testing, and open water validation to enhance development of marine energy technologies.

Michael Larson, Ph.D., Senior Researcher and Group Manager, Water Power Technologies, The National Renewable Energy Laboratory: This is a really exciting time to be a researcher in marine energy. The industry is at such a nascent stage of development where there's many technologies out there that have the potential to become commercially successful, and it's just really fulfilling to get to work with those companies and innovators to understand and develop the next generation of technologies that ultimately will become our commercial energy solutions in the future.

[The NREL logo with the tagline "Transforming Energy" appears on screen. Additional text appears on screen: For more detailed information about marine energy technologies and tools, visit nrel.gov/water or schedule a visit to the National Renewable Energy Laboratory! Thank you to our partners and contractors for supplying footage: Coastal Studies Institute, IKM Testing UK, Ocean Renewable Power Company, Oregon Wave Energy, Pacific Marine Energy Center, The Bureau of Reclamation, and Verdant Power.]