In order for the tidal stream energy sector to achieve commercial maturity, procedural improvements must be made in order to increase economic viability. This thesis targets the site selection procedure specifically. The aim is to improve the established method of site selection and increase the capability of this project phase, by demonstrating the sensitivity of Levelised Cost of Energy (LCoE) to metocean site characteristics. Historically, site selection for tidal stream energy has focused upon high flow/power locations, with the reasoning that large financial return will offset high lifetime costs such as Operations and Maintenance (O&M). The impact of metocean conditions on these lifetime costs is rarely considered, which generates falsely favourable LCoE predictions. The novel Levelised cost of Energy Site Selection (LESS) Tool presented herein utilises a computationally efficient augmented Weibull Persistence Method (WPM) to identify accessible tidal flow windows, and then calculate the probability that these predictable O&M windows will be hindered by wind and waves. Standby hours and metocean induced operational downtime are then calculated alongside standard energy yield estimates, to predict LCoE at discrete locations and over large regions. The LESS Tool requires flow and wave time series of one year duration in order to calculate LCoE. However, this data is often difficult and costly to obtain. Therefore, a cost-effective Incremental Site Assessment (ISA) procedure is proposed and presented, which utilises freely available online data and low-cost in-situ data collection methods in conjunction with hydrodynamic modelling to decrease the number of expensive detailed site assessments. The ISA was contrasted against a standard site assessment procedure and proved to be the most cost-effective in the vast majority of scenarios, with its capital cost reduction capability increasing with the number of potential deployment sites to be assessed. The LESS Tool was applied to a case study scenario at the Bay of Fundy (BoF), with Sustainable Marine tidal platforms used as case study devices. Detailed in-situ metocean data was used to calculate LCoE predictions at discrete locations within the BoF, and to validate Delft3D hydrodynamic models created according to the methods proposed by the ISA. The spatially-varying metocean outputs of the Delft3D model and LCoE predictions matched closely with discrete data points. Areas of high flow are generally seen to deliver the most energy, but sheltered sites with moderate flow speeds and longer access windows are seen to be the most economically viable in terms of LCoE.
