The Energy Blog St Helier West Primary substation

Reinforcing the network

After several months of structural and civil analysis and preparatory work, groundworks got underway in January 2016 on Jersey Electricity’s new £17m St Helier West primary substation on the old quarry site at Westmount Gardens. 

Local firm Jayen Ltd were awarded the Civil Works contract at the start of December 2015 and their engineers moved on site at the start of the New Year. Part of their work will involve removing the old quarry retaining wall and building a new retaining wall to protect the substation which is expected in service in 2018. The landscaping and footpaths restoration are expected to be finished towards the end of 2018.

The new facility is vital to protect existing electricity supplies to over 13,000 customers in the south, north and west of St Helier and enable new supplies in an area where Jersey Electricity’s network has been at near capacity for some time and infrastructure is aged and stressed.

JE identified a need to reinforce its network in this area as long ago as 2006. The Company was in talks with the Parish and States planning officials for several years and examined six possible sites before it was able to acquire the 10,000 sq ft Westmount site from the Parish for £250,000 in September 2014. In addition, the Parish received further £83,000 from the States for an urban renewal project and a gift of land near Overdale Hospital that will effectively extend the western end of Westmount Gardens.

Since then Jersey Electricity worked on identifying and assessing the ground conditions to ensure the specification for the Civil Works was properly prepared and the old quarry wall could be safely removed while maintaining the ground stability.

Before the civil investigations could begin, the site was cleared of undergrowth and protected green lizards, identified during an Ecological Study, had to be temporarily re-homed and perimeter hoarding erected to prevent them returning until the works are complete.

JE CEO Chris Ambler said: ‘The Westmount Quarry site has, as expected, proved challenging and this has required a considerable investigative and civils design work but I am delighted that work on site is now underway. St Helier West is an important part of our extensive, on-going, network investment programme to meet the ever increasing demand for low carbon electricity.’