Sea level rise will change estuarine tidal energy: A review

Abstract

Climate change induced sea level rise (SLR) is likely to impact estuarine hydrodynamics and associated processes, including tidal energy. In this study, a hierarchy of factors influencing the future of estuarine tidal energy resources is proposed based on their relevance to SLR. These include primary factors (e.g., tidal prism, tidal range, tidal current, tidal asymmetry), secondary factors (e.g., sediment transport), and tertiary factors (e.g., shifts in estuarine shape/landform). The existing uncertainty regarding SLR impacts on tidal energy resource is high, given the spatial variability of estuaries. SLR may cause tidal ranges or currents to strengthen or weaken, depending on estuarine shape and boundary conditions (e.g., presence or absence of levees and adjacent low-lying areas). To date, local site studies have not resulted in an overarching assessment of SLR effects on tidal energy resources and comparative studies encompassing different regions and estuary types are recommended in order to address the existing knowledge gaps and provide insights for policymakers and stakeholders. SLR implications to estuarine tidal energy resources may be particularly important as SLR-induced changes can alter the available resource within a renewable energy development's operational lifetime (∼20–30 years for tidal stream devices and ∼120 years for tidal barrages). In this regard, broader environmental impacts, as well as techno-economic assessments, are difficult to predict and long-term management decisions associated with harnessing the potential of tidal energy schemes within estuaries should be made with caution.