Korea has developed various new and renewable energy resources since 2000 due to increasing demand for Green Energy around the world. Because the west coast of Korea has an extreme tidal range, many research projects aimed at harnessing tidal energy have been conducted there successfully. Though the study of Dynamic Tidal Power (DTP) was started as a new tidal energy source about 20 years ago, its characteristics are not yet fully understood. DTP has the potential to have less environmental impact than does a conventional barrage type tidal power generator. Its characteristics were analyzed in many test cases using a numerical model. The theoretical maximum tidal power of DTP became the same as the maximum tidal range by controlling the phase difference. This showed that DTP has great potential for a very successful future in the Yellow Sea. Moreover, DTP could provide an attractive energy source even in areas of lower tidal range than indicated in previous studies.

Analysis of characteristics of Dynamic Tidal Power on the west coast of Korea

Dai, P.; Zhang, J., and Zheng, J., 2017. Predictions for dynamic tidal power and associated local hydrodynamic impact in the Taiwan Strait, China. Dynamic tidal power systems are a new alternative to tidal barrage systems for extracting tidal potential energy. In these systems, a dike perpendicular to the coast is used to create a water head, which is then converted into electricity. In this study, a mathematical model was developed using Delft3D FLOW to evaluate the power output and hydrodynamic consequences of a dynamic tidal power system in the Taiwan Strait. The model is composed of a coarse-resolution subdomain and a fine-resolution subdomain, and a domain decomposition technique was adopted to simulate flow through the interfaces of these subdomains. In the simulation, the mean power reached its maximum (0.89 GW) at a dike open ratio of 8%. The power system strongly affected the M2 tide in the local region. Overall, the amplitude of the M2 tide increased on the NE side of the system and dec...

https://bioone.org/journals/Journal-of-Coastal-Research/volume-33/issue-1/JCOASTRES-D-16-00068.1/Predictions-for-Dynamic-Tidal-Power-and-Associated-Local-Hydrodynamic-Impact/10.2112/JCOASTRES-D-16-00068.1.pdf

Predictions for Dynamic Tidal Power and Associated Local Hydrodynamic Impact in the Taiwan Strait, China

The numerical predication of the power performance of a marine current turbine is difficult due to its complex geometry and fluid-structural interactions. In this paper, an immersed boundary method is used to couple the simulation of turbulent fluid flow with solid using a three-dimensional finite volume solver. The method was then validated by various studies including the simulation of flow past an oscillating cylinder at a low Reynolds number. The power coefficients of a horizontal axis marine current turbine (MCT) with different rotating speeds is calculated and compared against the experimental data. It can be found that the method is in general agreement with published results and provides a promising potential for more extensive study on the MCT and other applications. Key-Words: marine current turbine, immersed boundary method, power performance, TSR

Numerical Simulation of a Marine Current Turbine in Turbulent Flow

Dynamic tidal power is a new way of capturing tidal energy by building a water head using a dike perpendicular to the coast. This study explored the hydrodynamic mechanism of the water head across an intended dynamic tidal power dike system using the Delft3D-FLOW software module. The propagating wave was simulated in a rectangular domain with a horizontal sea bottom at a 30-m depth. A significant water head was created across the dike by blocking the water. The water head increased with increasing dike length and increasing undisturbed tidal current acceleration. The maximum water head for the dike with a length of 50 km, located 900 km from the western boundary, was 2.15 m, which exceeded the undisturbed tidal range. The time series of the water head behaved in a manner identical to the undisturbed tidal current acceleration. The distribution of the water head over the dike assumed an elliptical shape. A parasitic wave was generated at the attachment and scattered outward. The phase lag across the dike did not behave as a linear function of the detour distance.

Numerical study of hydrodynamic mechanism of dynamic tidal power

Phase-shift tidal power system with a dam deployed perpendicularly to a coastline in the sea is considered. The tidal power is extracted from water level difference on both sides of the dam, which originates from different propagation path of the tidal wave and the phase shift in water levels. This study focuses on hydrodynamic characteristics of a Y-shaped dam under the action of the tidal waves and explores the effects of the dam parameters on the phase shift of the tidal waves on both sides of a main dam and water head. A two-dimensional model is used to simulate tidal flows in the Taiwan Strait and Qiongzhou Strait. The model is validated by comparing the numerical results with previous studies and available measurements. The influence of the angle between the main dam and the branch dam, branch dam length, and dam types on phase difference in water levels and water head over the main dam is discussed.

Hydrodynamic study of phase-shift tidal power system with Y-shaped dams

Until recently there were just two options to exploit tidal power: (1) Tidal Basin (with artificial and/or natural boundaries), and (2) Free Turbines mounted in a natural tidal stream (either in solitary mode, in park array, or lined up). Both methods have shown their technical feasibility. They may be seen as complementary, both having particular preferred locations as well as various pros and cons under technical, economic and environmental scrutiny. Both methods, smartly devised as they are, do exploit tidal power in a straightforward way. Both methods focus on a different, ‘one-dimensional’ element isolated from the complex natural tidal wave phenomenon, thereby using this element perhaps in a somewhat ‘passive’ way, i.e. just in the form it is offered on location by nature. The Tidal Basin method only exploits the naturally existing local water level range which is turned into an exploitable head, while the Free Turbines method only exploits the naturally existing local current velocity, extracting a part of its available kinetic energy. As a quite different option nr. 3 we have developed a more ‘3-D’ and ‘active’ tide exploiting method: Dynamic Tidal Power (DTP). It is characterized by (a) actively interfering in specific regional dynamic tidal systems, (b) using long dams (fitted with turbines) attached to and perpendicular to the coast, (c) creating a head over the dam, but avoiding a closed basin, (d) yielding massive amounts of electric energy, and (e) thereby providing this power at a virtually constant rate by applying twin dams working together in the right tidal phase lag. Due to its new hydraulic concept (patented), application of DTP focuses on areas where medium to strong oscillating tidal currents run more or less parallel to the coastline, typically encountered in semi-enclosed seas such as the North Sea, the Irish Sea and the Yellow Sea between China and Korea. DTP is complementary to both methods, and so appreciably adds to the world-wide potential of technically extractable tidal power. This paper discusses recent model results of DTP in coastal waters off China and Korea, yielding sometimes over 25 GW per DTP structure.

Gert Klopman

Papers

Dynamic Tidal Power (DTP) - A new approach to exploit tides