OES-Environmental distributes metadata forms (questionnaires) to solicit information from developers involved in environmental monitoring around marine renewable energy project sites around the world. This page provides project descriptions, baseline assessment, post-installation monitoring, and links to available data and reports. Content is updated on an annual basis.

Nova Innovation - Shetland Tidal Array

Description

The first three Nova M100 devices (installed capacity 300 kW) were deployed in 2016 and 2017. This was the world’s first offshore tidal array to supply electricity to the grid with greater than 17,000 generating hours reached in 2019. These turbines have continued to generate and export electricity to the grid since then.

In 2018 licences were granted to extend the array to six turbines (increase capacity to 600 kW). In 2018, Nova Innovation worked with Tesla to add energy storage to their tidal technology. This created the world’s first grid connected tidal power station with the ability to deliver baseload (constant, steady state) power and deliver energy on demand to meet consumer needs.

In August 2020 a fourth 100 kW turbine was added to the array. This was the next generation of Nova's M100 turbine, with no gearbox (direct drive). A further two 100 kW turbines were installed in 2023, taking the total to six. An offshore hub was also installed, enabling a single export cable to take the power from the  fifth and sixth turbines to shore.

A comprehensive environmental monitoring programme has been gathering data from the operational array since the installation of the first turbine in Bluemull Sound and is ongoing. The primary objective of the monitoring programme is to gather data on nearfield interactions between marine wildlife and the operational turbines, with a focus on marine mammals and diving seabirds. This is achieved through two key activities:

  1. Subsea video monitoring of the turbine rotor-swept area using high-definition cameras attached to the turbines.
  2. Bird and mammal surveys carried out from a vantage point overlooking the project area to monitor presence and behaviour around the turbines.
     

Location

The Shetland Tidal Array is located in the Bluemull Sound, Shetland off the far north-east coast of mainland UK, between the islands of Yell and Unst.

Licensing Information

Marine Licence required from Marine Scotland Licensing Operations Team.
Offshore Works Licence required from Shetland Islands Council.
Onshore Works licence required from Shetland Islands Council.
Licence to disturb European Protected Species (EPS) required from Marine Scotland Licensing Operations Team.
 

Project Progress

First three turbines installed 2016-17. Fourth turbine installed 2020. Two more turbines and an offshore hub installed 2023.

Key Environmental Issues

Collision risk and disturbance to EPS. See https://marine.gov.scot/ml/marine-licence-shetland-tidal-array-extended-bluemull-sound-shetland-0664200009110

   

Papers, Reports, Research Studies

Licence application document:

Monitoring reports:

Baseline Assessment: Nova Innovation - Shetland Tidal Array

Receptor Study Description Design and Methods Results Status
Marine Mammals Encounter Rate Modelling (ERM) to inform collision risk Use of computer models to determine the potential for sensitive species to collide with turbine blades. A 98% avoidance rate was assumed. The following calculations are based on the assumption that the devices are operating for 73% of the time as estimated by Nova. All year predicted encounter rate – 3.96
Breeding season parameters based on seals-at-sea density figure – 4.00 		Encounter Rate Modelling (ERM) to inform collision risk
Birds Use of computer models to determine the potential for sensitive species to collide with turbine blades. A 98% avoidance rate was assumed. Use of computer models to determine the potential for sensitive species to collide with turbine blades. A 98% avoidance rate was assumed. Atlantic puffin (Breeding season ERM: 1.45; All year ERM: 1.36)
Red-throated diver (Breeding season ERM: 0.13; All year ERM: 0.15)
Northern gannet (Breeding season ERM: 0.00; All year ERM: 0.00)
Common guillemot (Breeding season ERM: 0.37; All year ERM: 0.36)
European shag (Breeding season ERM: 4.87; All year ERM: 11.25) 		Complete

Post-Installation Monitoring: Nova Innovation - Shetland Tidal Array

Stressor Receptor Study Description Design and Methods Results Status
Collision Birds, Fish, Marine Mammals Underwater video monitoring Nova Innovation has carried out extensive video monitoring of the turbines currently deployed in the area to assess the potential impact on marine wildlife. Each turbine is fitted with cameras that are triggered by the presence of wildlife. There have been no observations of any marine wildlife colliding with the blades. Fish, birds and seals have been observed on the cameras, however, both the fish and their predators were observed to leave the region of the turbines while tide was flowing (and blades were rotating), with fish moving to areas of lower flow on the seabed. Ongoing