The possibility of integrating energy harvesting devices into the bridge/tunnel structures along Coastal Highway Route E39 has been investigated in a feasibility study by the Norwegian Public Roads Administration (NPRA). The main advantage of integrating energy conversion devices in a structural element is the reduction of costs compared to stand-alone devices. The construction could be used as a foundation, a mooring point and provide a dry environment for electrical devices. Easy access to the production site could also reduce the cost for installation, operation and maintenance. Two important challenges related to harvesting renewable energy by infrastructure elements, without concerning about the energy source, are to store it or feed the energy to the grid. In the second case, tailoring generation to demand is of critical importance. Tasks such as supply and demand management, for instance, peak hour management, what kind of storage should be used - electrical or thermal - need be solved. Furthermore, integrating energy production devices in a structure might cause negative environmental impacts and affect the life expectancy and maintenance costs of such structures. The potential environmental impacts associated with renewable technologies are the consequences for bird life or marine fauna at the fjord crossing locations, as well as noise and visual impact. Thus, a sustainability assessment should be performed in order to quantify the ecological, economical and societal impacts of the suggested alternatives.