Hunterston converter
station & cable

A converter station is needed at Hunterston to convert the direct current (DC) electricity to alternating current (AC) so that it can be used within the existing electricity transmission system.

Converter station

In addition to installing a new high voltage connection, we need to convert the direct current (DC) electricity to alternating current (AC) at each end so that it can be used within the existing electricity transmission system. To do this we need to build a converter station at each end.

In Scotland, we are building a converter station in Hunterston, on the north face of Goldenberry Hill and adjacent to Hunterston power station.The site at Goldenberry Hill is the preferred location as it is situated close to the shore, adjacent to a significant industrial area and within an area that is not densely populated.   

On completion, the converter station will connect to a new substation adjacent to the site at Hunterston and switch electricity from AC to DC (or vice versa depending on the direction of operation) for onwards transmission of electricity by two underground AC cables, approximately 500m in length.

Construction of the converter station is being carried out by Siemens, and began in autumn 2013.

A computer-generated flyover of the construction of the converter station

Work to the end of 2014

Planning permission for the converter station was granted by North Ayrshire Council on 13 March 2013. 

Construction of the converter station is being carried out by Siemens, and began in autumn 2013. During this year we established the five-hectare ‘platform’ on which we will build the converter station, cutting it from the hillside rock and reusing this to minimise the amount of materials being transported to site.

We also made good progress on constructing the buildings that will house the majority of the electrical equipment

Work to the end of 2015

During the year we installed the transformers and other large electrical equipment, which were brought from the jetty by the wind turbine test facility to site by a specialist transport company. We also completed construction of the main buildings, which means we can carry out work inside whatever the weather.

Work completed in 2016

During 2016 we installed most of the equipment within the buildings. This is a significant task as, because of the potential for inclement weather in the area, the vast majority of equipment is housed inside for protection.

Work planned in 2017

This year we’ll be completing installation of the equipment within the buildings and commissioning the converter station so that power can flow along the Western Link. We’ll also be landscaping the site, planting more than 25,000 trees and shrubs.

Ayrshire cable

We have laid approximately 4km of underground DC cable from the new converter station south to a landfall at Ardneil Bay, where the marine cables come ashore. We have reinstated the majority of land in the area and, when we’ve joined the marine and land cables in 2017, we will remove the hard standing at our temporary compound on Portencross Road and reinstate the land.

A Scottish Hydro Electric project to reinforce the 132kV transmission network on Kintyre, which included laying a subsea cable to Ardneil Bay and then underground cables to the new Hunterston North substation, is now complete.

Work to the end of 2014

To construct the cable, we established a temporary ‘working corridor’, around 30m wide, which we fenced off. The corridor runs from our temporary compound off Portencross Road in a northerly direction towards the converter station, over Thirdpart Holdings Road and across the fields towards Goldenberry Hill. It is wider than the corridor we’re using to install the underground cable on the Wirral peninsula, as it will also accommodate some preparation work for the Kintyre-Hunterston cable.  

Within this corridor we are installing two cables in a single trench approximately 1.2m deep and 750mm wide. The cables are being laid in sections of approximately 1km, with joints where the sections meet. The corridor is also being used to store material excavated from the trench dug for the cable and to install drainage and a temporary road for the delivery of the cable, which arrives on large drums.

By the end of 2014 we had laid the first few sections of the underground cable.

Joining the marine cable to the land cable is a very complex operation, and first needs pipes to be installed which will enclose the cables. Using a technique known as horizontal directional drilling (HDD) we drilled from our compound, under Portencross Road and West Kilbride Golf Course and out to a landing point in Ardneil Bay.

At the end of 2014, we started installing the first of two 600-metre long plastic pipes through the drill hole we had created, pulling the pipe from a barge moored offshore. 

Work in 2015 and 2016

During these two years we completed pulling both pipes from the barge to our temporary compound. We also completed installation of the underground land cables and reinstated the majority of the land.

Work planned in 2017

In early 2017 we will be pulling the marine cables through the pipes that we’ve installed. The marine cables will be pulled from a barge anchored offshore, through the pipes to our temporary Portencross Road compound, where we will join them to the land cables.

Once this work is complete we will remove the hard standing at the compound and reinstate the land.

The community

Community Liaison Group

We’ve tried to minimise disruption to the communities where we are constructing the northern converter station and the cables at Hunterston. So we could keep local people informed we set up a Community Liaison Group (CLG), to which we invited representatives from community councils, North Ayrshire Council, local businesses and other stakeholder groups. The group meets regularly with our project team.

The group discusses any issues that have arisen relating to construction work, such as traffic management, project timescales and noise. The group also considers any proposals that are put forward by charities or community representatives that will have a positive impact on the local community. Minutes from the CLG are uploaded here within six weeks of the latest meeting.

The members of the CLG are responsible for updating their local communities with information from the meetings and for passing information back to the project team if any issues and queries have been raised within the communities.

If you have any questions for the project team you can contact your local representative or get in touch with our Community Relations Team directly – all contact details can be found here

Archaeology

We have carried out archaeological work in support of the construction of the Hunterston converter station, the Hunterston East substation and the associated infrastructure. On 25 March 2015 we held a presentation on the initial findings of these archaeological excavations. The presentation, the information panels on display at this presentation and a leaflet giving more information on the work can be found on our documents page.

During 2016 we held two further presentations, to the Society of Antiquaries of Scotland and Glasgow Archaeological Society.

General

On Wednesday 27 November 2013 and on Wednesday 25 February 2015, we held public information events to update people on what is happening on the project.

All the information panels on display at the events and at the archaeology presentation, together with newsletters relating to the project, a leaflet on the archaeology, and more general technical documents relating to the converter station and cable, are on our documents page.   

Fly-over video