Presenter: Kevin Haas (Georgia Tech)

Description:
To evaluate the viability of tidal energy projects, resource assessments are required for computing the annual energy production (AEP). The first edition of the IEC technical specification (TS) for tidal energy resource assessment and characterization, TS 62600-201, provides a unified and internationally accepted methodology for producing the velocity probability distributions at locations of tidal energy converters (TEC) such that the AEP can be accurately computed. However, the uncertainties of the AEP estimation are rarely extensively discussed in numerical and observational studies that adopt the guidelines of the technical specification. Within the TS, two different approaches are outlined, using numerical models or following a measurement based methodology. For smaller projects, the measurement based approach may be the most economical method. The present methodology specifies the deployment of fixed instruments at each TEC location for at least 90 days. This study evaluates the sensitivity of uncertainty of the AEP estimates based on different parameters such as the duration of the measurements. In addition, a new approach is under consideration, coupling one or more fixed instrument (FI) current profiler measurements with mobile vessel (MV) current profiler measurements. The full length tidal currents time series MV sites are inferred from the long-term FI tidal current measurement and are used to generate the probability distribution for each site to be used for the AEP calculation. This study evaluates the methodology by using synthetic data for over 100 example turbine arrays utilizing numerical model data from the US tidal energy database. Through these analysis, we aim to (a) quantify the uncertainty of AEP assessment, including their spatial distribution and temporal variation and (b) provide statistically robust guidelines on best practices for future measurements and choosing the most appropriate assessment methodologies.