Environmental Effects of Marine Renewable Energy: the 2020 State of the Science Report

Submitted by Dorian Overhus on Jun 08, 2020

The 2020 State of the Science Report was released on 8 June 2020 by Ocean Energy Systems (OES)-Environmental, supported by the  International Energy Agency, and dedicated to examining the environmental effects of marine renewable energy (MRE) development. The 300-page report is the most comprehensive international analysis to date on the issue, based on studies and monitoring from publicly available, peer-reviewed scientific literature and reports. The 2020 report builds upon the 2013 Final Report for Phase 1 of OES-Environmental and the 2016 State of the Science Report. The report can help MRE developers consider how to design, site, and operate devices; avoid any impacts to marine animals and environments; provide information to government regulators; and inform the broader research community of the latest findings.

Topics addressed in the 2020 State of the Science Report include:

  • Underwater noise
  • Electromagnetic fields
  • Changes in oceanographic processes, including circulation, wave height, sediment transport patterns, water quality, and marine food webs
  • Changes in benthic and pelagic habitats
  • Encounters with moorings and cables
  • The risk of a marine mammal or fish colliding with a device
  • Environmental monitoring technologies, techniques, and strategies
  • Social and economic data collection
  • Marine spatial planning
  • Adaptive management
  • Risk retirement and data transferability
  • Path forward

The authors reported that, with the few MRE devices deployed to date, no marine mammals, fish, or seabirds have ever been observed colliding with a device. Additionally, there was no evidence of harm from underwater noise from operational devices or electromagnetic fields emitted from electric cables; no significant changes in habitat have been caused by MRE devices; and potential changes to oceanographic systems or entanglement of marine animals with mooring systems or cables pose very low risks. Although the potential impact to marine life is likely small or undetectable, scientists say there is still uncertainty around some issues, as there have been relatively few sizable deployments of MRE devices around the world where data can be collected.

With the ocean covering more than 70 percent of the Earth’s surface, drawing upon the power of the ocean to provide electricity would reduce the carbon footprint from energy production, provide grid stability in remote, coastal areas, and could add $3 trillion to the global economy. Developing a fraction of available energy from MRE could result in clean, reliable power for hundreds of millions of homes world-wide. MRE development is also expected to create new jobs in supply chain companies and environmental consultancies.