The Scottish & Southern Electricity Network (SSEN) has just finished a string of consultation meetings with the public in Orkney about developing a transmission infrastructure. This would include subsea cabling, underground cabling, substation construction and a variety of sizes of overhead power lines.
In 2014 a new substation for the Bay of Skaill and a subsea cable to the Scottish mainland were all put on hold when marine energy developments on the West Mainland were withdrawn. The substation for the Bay of Skaill has subsequently been cancelled.
Five developers wishing to go ahead in Orkney would be unable to do so if SSEN’s proposed infrastructure does not happen. These are:
- Westray South Tidal 60MW
- Brims Tidal 30MW
- Hesta Head Wind Farm 20.4 MW
- Costa Head Wind Farm 20.4 MW
- SHEPD (Finstown/Stenness) 50 MW
There is no capacity left in Orkney’s existing network for future developments. If Orkney wishes to produce renewable energy for the National Grid the transmission infrastructure would need to be in place.
An existing substation at Dounreay and a future substation planned for Gills Bay are possible connection points for a subsea cable running from Orkney to link into the National Grid.
Once on land in Orkney a variety of overhead lines and underground cables would be required to traverse the landscape. The overhead lines would vary in height from 11m up to 30m depending on what was required or permitted. New substations at Finstown including one at either Stenness/Orphir or South Ronaldsay would also be required.
There are to be further public consultations in the summer and bird surveys will commence in the next few weeks.
Construction is planned for 2020 if the project gets the go ahead.
Responsibility for policy areas relating to renewable energy and carbon emissions is divided between the UK and Scottish Governments. In Scotland and Wales electricity, including support for the generation of renewable electricity, is a reserved matter and therefore the responsibility of the UK Government.
The Orkney development comes at a time when the UK Government has withdrawn its support for onshore renewables and reduced it for others. A decision is still to be made by the UK Government if wind generation on our many islands will be included with mainland UK in the withdrawal of support.
Also thrown into the mix is the announcement by NorthConnect to construct a subsea cable between Sima, Norway and Peterhead, Scotland.
“ The cable would make it possible to export the large electricity surplus in Norway and to import wind power from Scotland to Norway. It is estimated that the net annual power exports from Norway could be between 5-9 TWh.” GREBE Renewable Energy Blog
The problem for Orkney is: all five developments have to get the go ahead to make the planned transmission infrastructure by SSEN feasible. If the infrastructure is not there future exporting of electricity to the National Grid by renewables in Orkney cannot take place. This would be a major blow for the renewable sector in Orkney.
And in the meantime the subsea interconnector between Norway and the Scottish mainland is going ahead.
Reporter: Fiona Grahame
The Renewable Energy Sector in Scotland: First Report of Session 2016 – 17:Scottish Affairs Committee: House of Commons