17. Technical and economic uncertainties

Foundation uncertainties are lower than for most hydroelectric developments. Foundations are generally favourable for medium and high tide areas, including rock, sand and gravel. Foundation materials may be finer in low-tide areas, but the corresponding problems have already been solved in the Netherlands, for example, for comparable structures.

Construction methods are not innovative. The large size of the structures is not an obstacle to 6- or 7-year lead-times, as the worksites can be separated.

There are two uncertainties in assessing production:

• very high tides at certain sites correspond to a resonance phenomenon, and the construction of facilities that take a significant share of the potential can reduce the height of the natural tide near the basin. This applies mainly in areas with...