Resource assessment for future generations of tidal-stream energy arrays. (1st April 2015)

• Record Type: Journal Article
• Authors: Lewis, M.; Neill, S.P.; Robins, P.E.; Hashemi, M.R.
• Is Part Of: Energy. Volume 83(2015)
• Page Start: 403
• Page End: 415
• Publication Date: 2015-04-01
• Subjects: Tidal energy -- Tidal resource -- Tidal modelling -- Tidal-stream turbine -- Hydrodynamic model resolution -- Irish Sea; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2015.02.038
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Tidal-stream energy devices currently require spring tide velocities ( SV ) in excess of 2.5 m/s and water depths in the range 25–50 m. The tidal-stream energy resource of the Irish Sea, a key strategic region for development, was analysed using a 3D hydrodynamic model assuming existing, and potential future technology. Three computational grid resolutions and two boundary forcing products were used within model configuration, each being extensively validated. A limited resource (annual mean of 4 TJ within a 90 km 2 extent) was calculated assuming current turbine technology, with limited scope for long-term sustainability of the industry. Analysis revealed that the resource could increase seven fold if technology were developed to efficiently harvest tidal-streams 20% lower than currently required ( SV > 2 m/s) and be deployed in any water depths greater than 25 m. Moreover, there is considerable misalignment between the flood and ebb current directions, which may reduce the practical resource. An average error within the assumption of rectilinear flow was calculated to be 20°, but this error reduced to ∼3° if lower velocity or deeper water sites were included. We found resource estimation is sensitive to hydrodynamic model resolution, and finer spatial resolution (<500 m) is required for regional-scale resource assessment when considering future tidal-stream energy strategies. Highlights: Tidal-stream resource assessment of Irish Sea using a 3D tidal model. Tidal-stream energy resource presently limited by practical device constraints. Tidal currents not rectilinear between flood and ebb direction at many sites. Resource improves if lower tidal-stream and deeper water technology developed.