Annex IV 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 Tiday Array (Bluemull Sound)

Project Site Annex IV

Title: Nova Innovation - Shetland Tiday Array (Bluemull Sound)
Start Date:
March 01, 2016
Technology Type:
Info Updated:
November 13, 2017
Project Status: 
Device in operation
Two bladed, seabed mounted tidal turbine, M100 device
Project Scale: 
Array - three devices (due to increase to six in 2019)
Installed Capacity: 
300 kW

The Scottish tidal energy developer installed the first Nova M100 turbine in the Bluemull Sound, Shetland in March 2016.  The device has been generating up to full power and across all tidal conditions. The second in a series of three 100 kW turbines was deployed alongside the first turbine in August 2016, making this the first offshore tidal array in the world to deliver electricity to the grid. In February 2017 the third turbine was installed and grid connected.


Bluemull Sound, Shetland in water greater than 30m deep.

Process Status: 

After successful operation of the three turbines Nova, in May 2017, secured around £190,000 in capital support to build and operate an energy storage solution for the Shetland Tidal Array.


The key aim of the project is to demonstrate the economic and technical benefit of Nova Innovation’s combined Renewable Energy and Storage system (REStore) to expand and overcome grid constraints.


The REStore system combines storage with renewable generation to allow control of output to the grid, contributing to grid stability developing baseload tidal power.


The company also secured its place in the €20.2 million project Enabling Future Arrays in Tidal (EnFAIT). The project which began in uly 2017 and will run until June 2022 was won as a competitive contract awarded by the European Union’s Horizon 2020 research and innovation programme to develop marine energy sources and demonstrate technologies in European waters. The project is a flagship initiative for the EU and marine energy, and aims to increase the commercial viability of tidal power.

It will extend the Bluemull Sound array to six turbines and demonstrate that high array reliability and availability can be achieved using best practice maintenance regimes. The layout of the turbines will be adjusted to enable array interactions and optimisation to be studied for the very first time at an operational tidal energy site.

Licensing Information: 

The only condition of the project was that the Licensee must ensure that the works are carried out in accordance with the agreed EMMP. If through monitoring, as directed by the EMMP, it is determined that the devices could have an adverse effect on site integrity then further mitigation measures may be required at the discretion of the licensing authority.


The marine licence document and other information can be found at the following link:

Key Environmental Issues: 

The key environmental issues identified were the potential for impacts on qualifying features of Yell Sound SAC and Hermaness, Saxa Vord and Valla Field SPA. The main concern surrounding this was collision with the turbine blades. The species specifically considered were Harbour Seal Phoca vitulina (for Yell Sound SAC) and the following species for Hermaness, Saxa Vord and Valla Field SPA:


  • Morus bassana (Gannet)
  • Fratercula arctica (Puffin)
  • Gavia Stellata (Red-throated diver)
  • Uria aalge (Guillemot)
  • Phalacrocorax aristotelis (Shag)

It was advised by SNH in 2013 that the conservation objectives of the aforementioned protected sites that require to be considered further are:


  • Population of the species as a viable component of the site
  • No significant disturbance of the species
Nova Innovation - Shetland Tiday Array (Bluemull Sound) is located in United Kingdom.

Baseline Assessment: Nova Innovation - Shetland Tiday Array (Bluemull Sound)

General Description:

Due to the small scale of the project an Environmental Impact Assessment (EIA) was not required to be carried out, however due to the project’s proximity to a Special area of Conservation and 4 Special Protection Areas an Appropriate Assessment was carried out to determine the potential for Likely Significant Effects of the project.

ReceptorStudy 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 – 3.3. Breeding season parameters based on seals-at-sea density figure – 3.33.

  • Sea and Shorebirds

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.


Breeding season ERM

All year ERM

Atlantic puffin



Red-throated diver



Northern gannet



Common guillemot



European shag



Reports and Papers

Nova Bluemull Sound - Appropriate Assessment

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