On the wave energy potential along the eastern Baltic Sea coast

We analyse the wave energy resource theoretically and practically available in a semi-sheltered shelf sea of moderate depth and with relatively severe but highly intermittent wave climate on the example of the Baltic Sea. The wave properties along the entire eastern Baltic Sea coast, from the Sambian (Samland) Peninsula to the eastern Gulf of Finland, are reconstructed numerically for 1970-2007 with a spatial resolution of 3 nautical miles (5.5 km) and temporal resolution of 1 h using the third generation wave model WAM. Owing to the shallowness of the sea (54 m on average) the finite-depth dispersion relation is used in the estimates of the wave energy resources in the nearshore, at depths of 7-48 m where the WAM model provides adequate results. The average wave energy flux (wave power) over the 38 years in question is about 1.5 kW/m (at selected locations up to 2.55 kW/m) in the nearshore regions of the eastern Baltic Proper but much smaller, about 0.7 kW/m, in the interior of the Gulf of Finland and the Gulf of Riga. The total theoretical wave energy resource in the entire study area is about 1.5 GW. The existing and proposed marine protected areas limit the available wave energy resource down to ∼840 MW. The production of grid energy is complicated because of extremely high intermittency and strong seasonal variation of the wave properties and frequent presence of sea ice. Although the wave energy resources are of obvious interest at some locations, their use for supplying power into the grid is questionable and probably not feasible in the conceivable future.