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Scott Draper - One of the best experts on this subject based on the ideXlab platform.

  • the effect of bed roughness uncertainty on tidal stream power estimates for the Pentland Firth
    Royal Society Open Science, 2020
    Co-Authors: M J Kreitmair, Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, T S Van Den Bremer
    Abstract:

    Uncertainty affects estimates of the power potential of tidal currents, resulting in large ranges in values reported for sites such as the Pentland Firth, UK. Kreitmair et al. (2019, R. Soc. open s...

  • The effect of uncertain bottom friction on estimates of tidal current power.
    Royal Society Open Science, 2019
    Co-Authors: M J Kreitmair, Scott Draper, Alistair G L Borthwick, T S Van Den Bremer
    Abstract:

    Uncertainty affects estimates of the power potential of tidal currents, resulting in large ranges in values reported for a given site, such as the Pentland Firth, UK. We examine the role of bottom ...

  • Subsea Cable Stability on Rocky Seabeds: Comparison of Field Observations Against Conventional and Novel Design Methods
    Volume 5: Pipelines Risers and Subsea Systems, 2018
    Co-Authors: Terry Griffiths, Scott Draper, Liang Cheng, Feifei Tong, Antonino Fogliani, David White, Fraser Johnson, Daniel Coles, Stephen Ingham, Caroline Lourie
    Abstract:

    As offshore renewable energy projects progress from concept demonstration to commercial-scale developments there is a need for improved approaches beyond conventional cable engineering design methods that have evolved from larger diameter pipelines for the oil and gas industry. New approaches are needed to capture the relevant physics for small diameter cables on rocky seabeds to reduce the costs and risks of power transmission and increase operational reliability. This paper reports on subsea cables that MeyGen installed for Phase 1a of the Pentland Firth Inner Sound tidal stream energy project. These cables are located on rocky seabeds in an area where severe metocean conditions occur. ROV field observation of these cables shows them to be stable on the seabed with little or no movement occurring over almost all of the cable routes, despite conventional engineering methods predicting significant dynamic movement. We cite recent research undertaken by the University of Western Australia (UWA) to more accurately assess the hydrodynamic forces and geotechnical interaction of cables on rocky seabeds. We quantify the conformity between the cables and the undulating rocky seabed, and the distributions of cable seabed contact and spanning via simulations of the centimetric scale seabed bathymetry. This analysis leads to calculated profiles of lift, drag and seabed friction along the cable, which show that all of these load and reaction components are modelled in an over-conservative way by conventional pipeline engineering techniques. Overall, our analysis highlights that current cable stability design can be unnecessarily conservative on rocky seabeds. Our work foreshadows a new design approach that offers more efficient cable design to reduce project capex and enhance through-life integrity management.

  • tidal stream power in the Pentland Firth long term variability multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • Tidal stream power in the Pentland Firth – long-term variability, multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

G T Houlsby - One of the best experts on this subject based on the ideXlab platform.

  • tidal stream power in the Pentland Firth long term variability multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • Tidal stream power in the Pentland Firth – long-term variability, multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • estimate of the tidal stream power resource of the Pentland Firth
    Renewable Energy, 2014
    Co-Authors: Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, G T Houlsby
    Abstract:

    The Pentland Firth is arguably the best-known candidate site for tidal stream power extraction worldwide. In this paper we estimate the maximum power that can be extracted by placing tidal stream power devices across the Pentland Firth and/or the individual sub-channels formed by the islands of Swona, Stroma and the Pentland Skerries. Using a depth-averaged numerical model, for the entire Firth we find that approximately 4.2 GW of power may be extracted, and this agrees reasonably well with predictions from an existing theoretical model. In contrast, for the sub-channels there is no single value to describe the power potential, but rather a range of power estimates because the extracted power from one sub-channel depends on the operation (or otherwise) of tidal devices placed in parallel sub-channels, or in series along the Firth. This range in output is of practical importance given present plans to lease separate sites within the Pentland to different device developers, and suggests that regulation of separate device developers will be crucial to achieve optimum performance across the entire Firth. Finally, we show that large scale energy extraction from the Pentland Firth does not lead to flow diversion around the Orkney Islands as a whole (as is sometimes assumed), however energy extraction in the Pentland Firth can augment the phase difference across smaller sub-channels in the Orkney Islands and this may increase their power potential.

  • an electrical analogy for the Pentland Firth tidal stream power resource
    Proceedings of The Royal Society A: Mathematical Physical and Engineering Sciences, 2014
    Co-Authors: Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, G T Houlsby
    Abstract:

    Several locations in the Pentland Firth, UK, have been earmarked for the deployment of separate farms of tidal turbines. However, recent numerical modelling suggests that these farms will be inter-dependent and that they must work together to optimize their collective performance. To explain this inter-dependence, in this paper we develop an electrical circuit analogy to describe flow through the Pentland Firth, in which parallel connections in the circuit represent different sub-channels formed by the islands of Swona, Stroma and the Pentland Skerries. The analogy is introduced in stages, beginning with turbines placed in a single channel, then turbines placed in a sub-channel connected in parallel to another sub-channel, and finally more complicated arrangements, in which turbines are installed both in parallel and in series within a multiply connected channel. The analogy leads to a general formula to predict the tidal power potential of turbines placed in a sub-channel connected in parallel to another sub-channel, and a predictive model for more complicated multiply connected channel arrangements. Power estimates made using the formula and predictive model (which may be applied using only measurements of the undisturbed natural tidal hydrodynamics) are shown to agree well with numerical model predictions for the Pentland Firth, providing useful insight into how to best develop the resource.

  • the available power from tidal stream turbines in the Pentland Firth
    Proceedings of The Royal Society A: Mathematical Physical and Engineering Sciences, 2013
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    This paper assesses an upper bound for the tidal stream power resource of the Pentland Firth. A depth-averaged numerical model of the tidal dynamics in the region is set-up and validated against fi...

Thomas A A Adcock - One of the best experts on this subject based on the ideXlab platform.

  • the effect of bed roughness uncertainty on tidal stream power estimates for the Pentland Firth
    Royal Society Open Science, 2020
    Co-Authors: M J Kreitmair, Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, T S Van Den Bremer
    Abstract:

    Uncertainty affects estimates of the power potential of tidal currents, resulting in large ranges in values reported for sites such as the Pentland Firth, UK. Kreitmair et al. (2019, R. Soc. open s...

  • Power and Thrust Capping of Tidal Stream Turbines: A Case Study of the Pentland Firth
    Volume 10: Ocean Renewable Energy, 2018
    Co-Authors: Tuo Wang, Thomas A A Adcock
    Abstract:

    It will not be practical for tidal stream turbines to extract all the peaks in energy over the tidal cycle. It is widely assumed that some form of power capping strategy will be required. In this paper we examine this using a 2D shallow water model of tidal hydrodynamics of the Pentland Firth. We argue that in addition to power capping, it is sensible to control the turbines to limit the peak thrust on them. We show that this can lead to a significant reduction in the peak thrust applied to the turbines and smaller changes to the naturally occurring flow rate whilst having a minimal effect of the mean power generated.

  • tidal stream power in the Pentland Firth long term variability multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • Tidal stream power in the Pentland Firth – long-term variability, multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • estimate of the tidal stream power resource of the Pentland Firth
    Renewable Energy, 2014
    Co-Authors: Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, G T Houlsby
    Abstract:

    The Pentland Firth is arguably the best-known candidate site for tidal stream power extraction worldwide. In this paper we estimate the maximum power that can be extracted by placing tidal stream power devices across the Pentland Firth and/or the individual sub-channels formed by the islands of Swona, Stroma and the Pentland Skerries. Using a depth-averaged numerical model, for the entire Firth we find that approximately 4.2 GW of power may be extracted, and this agrees reasonably well with predictions from an existing theoretical model. In contrast, for the sub-channels there is no single value to describe the power potential, but rather a range of power estimates because the extracted power from one sub-channel depends on the operation (or otherwise) of tidal devices placed in parallel sub-channels, or in series along the Firth. This range in output is of practical importance given present plans to lease separate sites within the Pentland to different device developers, and suggests that regulation of separate device developers will be crucial to achieve optimum performance across the entire Firth. Finally, we show that large scale energy extraction from the Pentland Firth does not lead to flow diversion around the Orkney Islands as a whole (as is sometimes assumed), however energy extraction in the Pentland Firth can augment the phase difference across smaller sub-channels in the Orkney Islands and this may increase their power potential.

Alistair G L Borthwick - One of the best experts on this subject based on the ideXlab platform.

  • the effect of bed roughness uncertainty on tidal stream power estimates for the Pentland Firth
    Royal Society Open Science, 2020
    Co-Authors: M J Kreitmair, Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, T S Van Den Bremer
    Abstract:

    Uncertainty affects estimates of the power potential of tidal currents, resulting in large ranges in values reported for sites such as the Pentland Firth, UK. Kreitmair et al. (2019, R. Soc. open s...

  • The effect of uncertain bottom friction on estimates of tidal current power.
    Royal Society Open Science, 2019
    Co-Authors: M J Kreitmair, Scott Draper, Alistair G L Borthwick, T S Van Den Bremer
    Abstract:

    Uncertainty affects estimates of the power potential of tidal currents, resulting in large ranges in values reported for a given site, such as the Pentland Firth, UK. We examine the role of bottom ...

  • tidal stream power in the Pentland Firth long term variability multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • Tidal stream power in the Pentland Firth – long-term variability, multiple constituents and capacity factor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Thomas A A Adcock, Scott Draper, Alistair G L Borthwick, G T Houlsby, Sena Serhadlioglu
    Abstract:

    The Pentland Firth, Scotland, is one of the World’s prime locations for the eventual installation of large farms of tidal stream turbines. This paper seeks to improve the upper bound estimate of available power output obtained by Adcock et al. (2013) who used a depth-integrated numerical model of the region containing the Pentland Firth with the outer boundary forced solely by M2 and S2 tidal constituents. Herein, the analysis is extended to include six additional tidal constituents and the model run for 11.5 years, more than half of the 18.6-year lunar nodal cycle, to allow variations over this to be analysed. The consequent increase in available power is estimated, and the variation in power output over an 11-year period is examined. Although further power could theoretically be extracted from the additional six tidal constituents, this would require the tidal turbine farm to have such a low capacity factor that it would probably be economically unfeasible.

  • estimate of the tidal stream power resource of the Pentland Firth
    Renewable Energy, 2014
    Co-Authors: Scott Draper, Thomas A A Adcock, Alistair G L Borthwick, G T Houlsby
    Abstract:

    The Pentland Firth is arguably the best-known candidate site for tidal stream power extraction worldwide. In this paper we estimate the maximum power that can be extracted by placing tidal stream power devices across the Pentland Firth and/or the individual sub-channels formed by the islands of Swona, Stroma and the Pentland Skerries. Using a depth-averaged numerical model, for the entire Firth we find that approximately 4.2 GW of power may be extracted, and this agrees reasonably well with predictions from an existing theoretical model. In contrast, for the sub-channels there is no single value to describe the power potential, but rather a range of power estimates because the extracted power from one sub-channel depends on the operation (or otherwise) of tidal devices placed in parallel sub-channels, or in series along the Firth. This range in output is of practical importance given present plans to lease separate sites within the Pentland to different device developers, and suggests that regulation of separate device developers will be crucial to achieve optimum performance across the entire Firth. Finally, we show that large scale energy extraction from the Pentland Firth does not lead to flow diversion around the Orkney Islands as a whole (as is sometimes assumed), however energy extraction in the Pentland Firth can augment the phase difference across smaller sub-channels in the Orkney Islands and this may increase their power potential.

Harshinie Karunarathna - One of the best experts on this subject based on the ideXlab platform.

  • 3D modelling of the impacts of in-stream horizontal-axis Tidal Energy Converters (TECs) on offshore sandbank dynamics
    Applied Ocean Research, 2019
    Co-Authors: Antonia Chatzirodou, Harshinie Karunarathna, Dominic E. Reeve
    Abstract:

    Abstract The tidal energy sector is a growing industry in the UK and beyond. Energy developers’ interests are progressing towards the deployment of large arrays of tidal energy converters (TECs). Numerous factors will affect decision making related to arrays siting and size. One key factor is the effect that the TEC arrays may have on the natural sediment transport patterns and the sea bottom morphodynamics. The Inner Sound Channel located between the Island of Stroma of Pentland Firth and the Scottish Mainland (UK) has been accredited for a large-scale TEC array installation to be developed in the future. Three morphodynamically active, large sandbanks are located in the Inner Sound channel. This study investigated the impacts of tidal energy extraction from a large array of TECs on the sediment dynamics and morphology of these sandbanks. A large-scale 3D hydrodynamic and morphodynamic Delft3D model was set up to computationally model Pentland Firth, Inner Sound Channel in order to study the impacts of tidal energy extraction from a generic TEC array, on the existing hydrodynamic and morphodynamic regime. A range of hypothetical energy extraction scenarios was modelled. Results reveal that the changes to morphodynamics of these sandbanks as a result of large scale tidal energy extraction far exceeds the morphology change under the natural hydrodynamic regime and that the severity of morphology change depends on the level of energy extraction.

  • the influence of waves on morphodynamic impacts of energy extraction at a tidal stream turbine site in the Pentland Firth
    Renewable Energy, 2018
    Co-Authors: Iain Fairley, Harshinie Karunarathna, Ian Masters
    Abstract:

    Abstract Extraction of energy from tidal streams has the potential to impact on the morphodynamics of areas such as sub-tidal sandbanks via alteration of hydrodynamics. Marine sediment transport is forced by both wave and tidal currents. Past work on tidal stream turbine impacts has largely ignored the contribution of waves. Here, a fully coupled hydrodynamic, spectral wave and sediment transport model is used to assess the importance of including waves in simulations of turbine impact on seabed morphodynamics. Assessment of this is important due to the additional expense of including waves in simulations. Focus is given to a sandbank in the Inner Sound of the Pentland Firth. It is found that inclusion of wave action alters hydrodynamics, although extent of alteration is dependant of wave direction. Magnitude of sediment transport is increased when waves are included in the simulations and this has implications for morphological and volumetric changes. Volumetric changes are substantially increased when wave action is included: the impact of including waves is greater than the impact of including tidal stream turbines. Therefore it is recommended that at tidal turbine array sites exposed to large swell or wind-seas, waves should be considered for inclusion in simulations of physical impact.

  • Modelling 3D hydrodynamics governing island-associated sandbanks in a proposed tidal stream energy site
    Applied Ocean Research, 2017
    Co-Authors: Antonia Chatzirodou, Harshinie Karunarathna, Dominic E. Reeve
    Abstract:

    Abstract A 3D numerical modelling study to investigate the existing hydrodynamic regime of the Pentland Firth Inner Sound Channel, Scotland, UK is presented. Hydrodynamics that govern some sensitive sedimentary deposits in the Inner Sound Channel are discussed. A 3D hydrodynamic model Delft3D is set up for Pentland Firth, located between Orkney Islands and mainland Scotland and a full sensitivity analysis of the numerical model is carried out. The current model set up sufficiently captures the existing hydrodynamics during a full spring-neap tidal cycle inside Pentland Firth. Using model results, the 3D structure of the dynamics of the tidal flows in the Inner Sound Channel is investigated. The temporal variability of tidal flows, the residual tidal flows in the channel and local flow interactions with the Island of Stroma are described. It is proved that the tidally dominant flows drive the sediment transport gradient model to explain the principle maintenance mechanisms of two island-associated sandbanks present in the Inner Sound. The present study provides detailed information on the physics of the tidal regime in the Inner Sound and explains the presence of sandbanks in an area of high tidal flows. Due to extremely high tidal flows, Inner Sound is considered as one of the most favourable sites for tidal energy extraction in the UK. The findings of this study will be very useful in assessing the significance of impacts of future tidal energy extraction on natural hydrodynamics and sediment dynamics of the area.

  • Investigation of deep sea shelf sandbank dynamics driven by highly energetic tidal flows
    Marine Geology, 2016
    Co-Authors: Antonia Chatzirodou, Harshinie Karunarathna, Dominic E. Reeve
    Abstract:

    Abstract In this paper we describe a numerical modelling study carried out to investigate the prevailing sediment dynamics of two large sandbanks located at a site designated for future development of tidal stream energy extraction, in the Inner Sound Channel of Pentland Firth, Scotland, UK. A calibrated and validated 3D Delft3D hydrodynamic model covering Pentland Firth channel was combined with a morphodynamic model. The sea bed changes occurring around the sandbanks during a period of two spring-neap tidal cycles are described and discussed in detail. It was found that both sandbanks, which are located in a deep shelf region (depths > 18 m), are morphodynamically active and their existence and integrity are strongly linked with the existing hydrodynamic regime.

  • the cumulative impact of tidal stream turbine arrays on sediment transport in the Pentland Firth
    Renewable Energy, 2015
    Co-Authors: Iain Fairley, Ian Masters, Harshinie Karunarathna
    Abstract:

    This contribution investigates the impact of the deployment of tidal stream turbine arrays on sediment dynamics and seabed morphology in the Pentland Firth, Scotland. The Pentland Firth is arguably the premier tidal stream site in the world and engineering developments are progressing rapidly. Therefore understanding and minimising impacts is vital to ensure the successful development of this nascent industry. Here a 3 dimensional coupled hydrodynamic and sediment transport numerical model is used to investigate the impact on sediment transport and morphodynamics of tidal stream arrays. The aim of the work presented here is twofold: firstly to provide prediction of the changes caused by multiple tidal stream turbine array developments to some of the unique sandy seabed environments in the Pentland Firth and secondly as a case study to determine the relationship between impacts of individual tidal stream farms and cumulative impacts of multiple farms. Due to connectivity in tidal flow it has been hypothesized that the cumulative impact of multiple arrays on sediment dynamics might be non-linear. This work suggests that, for the Pentland Firth, this is not the case: the cumulative impact of the 4 currently proposed arrays in the area is equal to the sum of the impacts of the individual arrays. Additionally, array implementation only has minimal effect on the baseline morphodynamics of the large sandbanks in the region, smaller more local sandbanks were not considered. These two results are extremely positive for tidal stream developers in the region since it removes the burden of assessing cumulative impact from individual developers and suggests that impacts to sub-sea morphodynamics is insignificant and hence is unlikely to be an impediment to development in the Pentland Firth with the currently proposed levels of extraction.