Energy flux measurement of tidal stream in a strait using two crossing ultrasonic transmission lines

Kiyoshi Kawanishi, Masoud BahrainiMotlagh, Mahdi Razaz

Tuesday 30 june 2015

9:15 - 9:30h at Antarctica (level 0)

Themes: (T) Special session, (ST) Marine renewable energy

Parallel session: 4D. Special session: Marine Renewable Energy

A tidal energy resource assessment was carried out in 2014 in the Nekoseto strait of the Seto Inland Sea, Japan, using Fluvial Acoustic Tomography System (FATS) with two crossing ultrasonic transmission lines. The lengths of the two transmission lines were 1204 m and 1622 m, respectively, and the maximum depth was 100 m. The central frequency of four broad-band transducers was 30 kHz. Unlike many resource assessments which use ADCPs, in the present study, FATS were deployed in the Nekoseto strait to measure cross sectional averaged velocity. The maximum cross-sectional average velocity measured by FATS was 1.0 m/s. The maximum values of the energy flux density and the energy flux were 0.5 kW/m^2 and 40 MW, respectively. Continuously monitoring the tidal currents and the energy fluxes is required without disturbing shipping, fisheries or marine aquaculture industries. The FATS can be installed on a coastline, seashore, riverbank or bridge, locations that are subjected to not only the passage of ships but also sedimentation and strong current forces.