The UK has outlined an ambitious plan to cut carbon emissions by 68% by 2020, shifting its energy sources from fossil fuels to renewable energy alternatives. Tidal stream technology, the process of harnessing the power of ocean tidal currents, presents a promising option to support the clean energy transition.

While the technology is reaching the point of commercial-scale deployment, sector growth has been hindered by economic challenges, and uncertainties surrounding potential environmental impacts on marine habitats and species during construction and operation.

In the UK, there are consenting concerns on the negative impacts tidal stream devices may have on marine fauna, including the risk of collision, disturbance caused by underwater noise, avoidance and displacement. These concerns have contributed to long consenting timelines and the need for costly long-term data collection to fill evidence gaps and understand these impacts.

Tidal stream collision risk data and evidence

To assess the impacts of tidal stream energy devices on marine species, The Crown Estate and ABPmer have collaborated on a report providing an overview of environmental monitoring data collected to date on consented (pre-construction), operational, or decommissioned tidal stream energy projects.

The data and evidence summarised in the report primarily explores the issue of collision risk for marine mammals, which remains a significant barrier to tidal stream consenting and a key concern for regulators.

The report draws insight from monitoring, and how monitoring conclusions can inform future tidal stream energy developments in the UK. A primary objective of the report has been to assess monitoring methods used at tidal stream sites, with particular focus on impact monitoring techniques, to better understand the evidence base relating to collision risk and possible displacement. By providing clarity on the advantages and limitations of tidal stream technology monitoring techniques, the report’s ultimate aim is to support the tidal stream energy consenting process.

Using The Crown Estate’s Marine Data Exchange (for which ABPmer undertakes data handling tasks essential to its effective management and use) and third-party peer reviewed journals, the report summarises monitoring data for five tidal energy sites in the UK:

• SeaGen Unit
• Shetland Tidal Array
• MeyGen Tidal Energy Project
• The European Marine Energy Centre
• The Morlais Demonstration Zone

The report also considers evidence gathered around the world to investigate lessons learned in other countries, including the USA, Canada and France. Each case study provides insights into the advances and limitations of monitoring techniques carried out at leach location.

Download the full report, “Tidal Stream Energy Project, Collision Risk Data and Evidence Summary”, at the Marine Data Exchange website.