Potential environmental impact of tidal energy extraction in the Pentland Firth at large spatial scales: results of a biogeochemical model

• Published in: Biogeosciences Vol. 13; no. 8; pp. 2593 - 2609
• Main Authors: van der Molen, Johan, Ruardij, Piet, Greenwood, Naomi
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 02-05-2016; Copernicus Publications
• Subjects: Analysis; Automation; Biogeochemistry; Carbon capture and storage; Carbon sequestration; Chlorophyll; Climate change; Computational fluid dynamics; Dispersal; Economic activity; Ecosystem assessment; Ecosystems; Energy; Environment models; Environmental aspects; Environmental economics; Environmental effects; Environmental impact; Farms; Fluid flow; Fluid mechanics; Hydrodynamics; Investigations; Licenses; Marine ecosystems; Ocean energy resources; Ocean floor; Primary production; Residual circulation; Salinity; Three dimensional models; Tidal energy; Tidal power; Tides; Scotland; Orkney Islands; North Sea; United Kingdom > UK; Liverpool Bay
• ISSN: 1726-4189; 1726-4170; 1726-4189
• DOI: 10.5194/bg-13-2593-2016

A model study was carried out of the potential large-scale (> 100 km) effects of marine renewable tidal energy generation in the Pentland Firth, using the 3-D hydrodynamics–biogeochemistry model GETM-ERSEM-BFM. A realistic 800 MW scenario and a high-impact scenario with massive expansion of tidal energy extraction to 8 GW scenario were considered. The realistic 800 MW scenario suggested minor effects on the tides, and undetectable effects on the biogeochemistry. The massive-expansion 8 GW scenario suggested effects would be observed over hundreds of kilometres away with changes of up to 10 % in tidal and ecosystem variables, in particular in a broad area in the vicinity of the Wash. There, waters became less turbid, and primary production increased with associated increases in faunal ecosystem variables. Moreover, a one-off increase in carbon storage in the sea bed was detected. Although these first results suggest positive environmental effects, further investigation is recommended of (i) the residual circulation in the vicinity of the Pentland Firth and effects on larval dispersal using a higher-resolution model and (ii) ecosystem effects with (future) state-of-the-art models if energy extraction substantially beyond 1 GW is planned.