As the U.S. Department of Energy’s Water Power Technologies Office (WPTO) works to help advance marine renewable energy (MRE) technologies, we recognize the importance of protecting our environment and the species that inhabit it. As we deploy and test MRE devices, it is vital to ensure that we are not disrupting the marine ecosystem and that these devices and marine life can safely coexist.

To better understand the impact MRE devices have on the marine environment, 30 marine scientists from around the globe spent the past four years reviewing existing data and research, resulting in the 2020 State of the Science Report—the most comprehensive report to date on the topic. This analysis complements years of previous research, which was captured in 2013 and 2016 reports. On behalf of WPTO and the International Energy Agency’s Ocean Energy Systems technology collaborative (that includes more than 20 other countries), Pacific Northwest National Laboratory released the final 2020 report in September. While more research is needed as technologies and industries advance, the results to date are extremely positive, finding that the impacts of single devices and small arrays on marine life is likely minimal.

The report looked at MRE devices and potential stressors, including the following:

  • Underwater noise
  • Electromagnetic fields
  • Changes in oceanographic processes such as circulation, wave height, sediment transport patterns, water quality, and marine food webs
  • Changes in seafloor and water column habitats
  • Encounters with moorings and cables
  • The risk of marine mammals or fish colliding with a device.

With the few small, non-commercial MRE devices deployed to date, not a single collision with marine mammals, fish, or seabirds has been recorded. There is also no evidence of harm due to underwater noise from operational devices or electromagnetic fields emitted from electric cables, no significant changes in habitat caused by MRE devices, and no potential changes to oceanographic systems or entanglement of marine animals with mooring systems or cables. MRE is an emerging industry that focuses on clean energy generated from ocean waves, tides, and currents; ocean temperature and salinity gradients; and river currents. And the resource potential is significant: by harnessing a fraction of available wave energy in U.S. waters, millions of American homes can be powered with clean, reliable energy. Furthermore, MRE can provide a host of benefits—reducing the carbon footprint of energy production, providing energy security in remote coastal communities, and powering economic, scientific, and national security missions out at sea. This report’s findings and continued research by marine scientists will be fundamental as the MRE industry continues to grow and more devices make their way to the water.


Alejandro Moreno
Alejandro Moreno is the Deputy Assistant Secretary for Renewable Power in the Office of Energy Efficiency and Renewable Energy (EERE).
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