E39 is a road that is located on the west coast of Norway and extends from Kristiansand in the south to Trondheim in the north. Currently, a number of ferry crossings are required to traverse its entire length. The Transport Ministry has given a mandate for the project “Ferry Free E39” to assess the technological solutions for the crossing of eight large fjords without ferries. The fjords crossings range from 1.5 km to 25 km in length and have depths up to 1300 m. Proposed solutions for the crossings that are under consideration consist of suspension bridges, floating bridges and submerged floating tunnels. Part of the project is to consider how the construction of the crossings can be combined with devices that produce energy from waves, tides, wind and the sun. The idea is that, by using the bridge construction as part of the facility, the costs of the renewable energy power plants could be reduced and therefore be more competitive.

SP Technical Research Institute of Sweden has been commissioned by the Norwegian Public Roads Administration to perform a technology survey and generate a summary of the current state of the art wave and tidal energy conversion technologies. Requests for information were sent to the majority of the active developers in order to obtain the most up to date information about the current technology status, performance data and conditions of functionality for each of the devices. The thoughts behind the questions asked in the requests for information and the results of this technology survey are presented herein.

Additionally, SP has been commissioned to make rough estimations of the potential energy that could be obtained from each fjord crossing by employing wave and tidal energy conversion technologies and to recommend the most suitable technology for integration with each fjord crossing concept. The methods behind the estimations of potential energy from each crossing and the background for the recommendations that are made are presented herein.

Unfortunately, a lack of tidal and wave energy resource data at the fjord crossing locations made it impossible to utilize the detailed calculation method that was described and a simplified calculation method was used to calculate rough estimates of the energy potential from the different devices. When the estimates were compared to previous studies it showed that the estimates based on the simplified approach were non-conservative. Source of non-conservatism in the calculations were discussed and it was concluded that the next stage of the study should concentrate on obtaining reliable data about the tidal and wave energy resources for the different fjord crossing locations. The data should be obtained over a significant period of time to ensure that the effects of seasonal variations in the resources are captured.

Once tidal and wave resources data is available, more realistic calculations of the potential energy production can be completed. At that point, comparisons of the performance of the difference technologies can be made.

From that point, more detailed studies should be undertaken where the concepts for combining the devices with the bridging technologies are optimized. This optimization should include actions such as loads analysis, structural strength 7 calculations, reliability and fatigue performance evaluations and detailed cost estimates.