Modeling the extraction of tidal energy from the hypothetical Orkney Islands Dam (northern North Sea) and from turbines in a tidal inlet

Abstract

This thesis contains two numerical analyses for two different models that simulate tidal motions. The first is a fundamental model describing a tidal inlet connected to the open sea by a 2 kilometers channel. The research focuses on the speeds through the channel, the water level in the inlet and eventually the power that can be obtained when adding a higher, speed dependent, value to the bottom drag already present. After a couple of iterations this results in a maximum power of 94.34 $MW$. As an extension the channel is split into one open and one turbine channel and it is found that on basins of sizes beneath 100 km$^2$ the open channel has a negative effect on the maximum obtainable power from the turbine channel and on basins of sizes above 1000 km$^2$ the open channel has no influence on the maximum obtainable power. The second is a full blown numerical model of the northern North Sea, mapping the water levels and velocities of the water through the Orkney channel. A dam is connected to the mainland and an open grid point with high bottom drag to calculate the power obtainable over this area. The power available in this model has an average of 3.71 $GW$, adding up to an energy supply of 32.5 $TWh/yr$. This hypothetical dam changes the tidal motions around the dam as well as along the United Kingdom's east coast, which could be of influence on the sea and plant life in these areas.