Investigating the Environmental Effects of Ocean Energy Generation (Invited)

The production of electricity from the moving waters of the ocean has the potential to be a viable addition to the portfolio of renewable energy sources worldwide. The marine and hydrokinetic (MHK) industry seeks to deploy and operate devices that harvest energy from the tides, waves, ocean currents and run of the river. Challenges facing the emerging industry include technology development, rigors of offshore deployments, and financing; however, the barrier most commonly cited by industry, regulators, and stakeholders is the uncertainty surrounding potential environmental effects of devices placed in the water and the permitting processes associated with those impacts. There is a need to evaluate the extensive list of potential interactions that may cause harm to marine organisms and ecosystems, to set priorities for regulatory triggers, and to direct future research. Project developers need information to understand how to minimize environmental effects; regulators need to know what monitoring targets are needed near ocean energy farms; and stakeholders need to know what mitigation strategies are effective in addressing unavoidable impacts. Scientists from Pacific Northwest National Laboratory (PNNL) are developing an Environmental Risk Evaluation System (ERES) to assess environmental effects associated with MHK technologies and projects through a systematic analytical process, with specific input from key stakeholder groups. The ERES development process provides the scientific structure to support risk characterization, comparison of tradeoffs, and risk-informed decision-making by project and technology developers, regulatory agencies, and other interested stakeholders. The PNNL team will determine the range and severity of environmental effects of MHK development, leading to the development of mitigation strategies where residual risk remains. Input to ERES draws from a wide range of marine and freshwater studies to understand which marine receptors may suffer damage from specific portions of MHK devices, mooring systems, or electrical cabling. However little is known about the effects of certain MHK stressors such as electromagnetic fields (EMF) from underwater cables and machines, as well as acoustic outputs from rotating turbines. Laboratory investigations into the effects of EMF and acoustics on test organisms will be discussed, and preliminary results presented.