ETTIE: A tool for streamlined tidal turbine life cycle assessment
Researchers from the University of Exeter have developed a new tool to streamline the Life Cycle Assessment of tidal turbine deployments. Life Cycle Assessment is used to quantify net greenhouse gas emissions, and is often required at project consenting stage, however it can be time consuming and complex to complete.
The tool, known as the ETTIE (Exeter Tidal Turbine Impact Estimator), allows developers to estimate the greenhouse gas emissions of a tidal turbine deployment based on early-stage design information. By using scalable pre-calculated modules based on a wide range of turbine types, materials and design decisions, the ETTIE tool can be used by non-specialists and reduces the time required for an assessment from months to hours, whilst maintaining compliance with international standards. ETTIE results have been shown to vary by less than 3% from those of full assessment.
The core goal of a renewable energy technology such as tidal stream energy is to replace fossil fuel combustion with reliable and clean energy. Working out how clean the electricity produced is, requires calculations of the greenhouse gas emissions of every aspect of the development, deployment, use and removal of the technology.. As part of the TIGER project, researchers at the University of Exeter have undertaken numerous assessments of turbine life cycle emissions and suggest that many deployments will offset their greenhouse gas emissions through the generation of clean electricity within the first three years after installation, and that total emissions are similar to those of more developed renewable energy technologies. This work also reveals that installation and maintenance can contribute up to 50% of total emissions.
The ETTIE tool and a step-by-step user guide are now available on the TIGER project website. The tool comprises five input sections, covering major turbine parts, device specification, site conditions and installation and maintenance. The tool can accommodate single or multi-device arrays of horizontal and vertical axis fixed or floating devices of any size, with a range of foundation types, cable layouts and maintenance strategies and vessels.
Figure 1: Sample ETTIE tool output showing emissions breakdown and headline results
The results sections give detailed breakdowns of impact and offset emissions based on deployment location and year. Charts can be copied for use in submission documents, with full data on background sources included in the user guide.
View the tool here: https://interregtiger.com/download/exeter-tidal-turbine-impact-estimator-ettie-tool/
Dr. Stuart Walker, TIGER Research Fellow, Université d’Exeter