Estimation of available wave power in the near shore area around Hanstholm Harbor

Abstract

The European target is to source 20% of the Europe's energy from renewable sources by 2020. Nowadays, wave energy is one of the renewable sources. Even though it has been estimated that wave energy could provide from 10% to 50% of the worldwide energy consumption, most of the Wave Energy Converters are still in the phase of R&D (research and development).

A reconstruction of Hanstholm Harbor is planned as well as a building of a wave energy center at Hanstholm. Therefore, it has been found interesting to estimate the available wave power.

The main aim is to estimate the magnitude of available wave power in the near shore area around Hanstholm Harbor in order to find out the importance of the mentioned source and the positions with highest available power in this area. Furthermore, the influence of wave conditions and wind in the availability of wave power could be of interest. Now, that the reconstruction has not started yet, it is the moment to verify if it is worth to change the reconstructed harbor properties to adequate it to further wave energy production.

The way to estimate the wave power has been as follows:

Firstly, the wave conditions have been determined at a Hanstholm buoy situated in a depth of 20 m. For this, the wave parameters have been selected, correlations between variables have been needed, data have been filtered and directionality has been associated to Hanstholm data.

Secondly, the available wave power has been estimated at the buoy. Scatter diagrams and probabilities of occurrence have been built in order to obtain the wave energy flux. All these diagrams have been built non-directionally and directionally as well. Then, for various wave directions, 10 sea states have been formed assembling waves with similar wave heights Hm0, wave periods Tm01 and wave energy fluxes Pwave.

The simulation of wave propagation has been executed by SWAN for each wave direction and each state, in order to have the propagated Hm0, Tm01 and direction at 11 different points in the near shore area around Hanstholm Harbor (gauges).

Finally, wave energy fluxes have been calculated with the propagated parameters. The results of Pwave depending on wave directions, on wave states and on the location of gauges have been analyzed.

As a conclusion, the available wave power obtained at the Hanstholm buoy has been around 6.16 kW/m (54 MWh/y/m) and at the gauges, around 5 kW/m.