Greenhall Highway and Waterside Projects repowered by Everun


A Vestas V29 on a 30m tower was installed at the Greenhall Highway site in August 2015 with a capacity of 225kW. The adjacent Waterside site was originally commissioned in February 2015 where a Vestas V29 on a 30m tower was also installed with a capacity of 225kW. 

Following a programme of repowering analysis, each of the sites were identified as having the capability of a greater yield via repowering. The feasibility of a number of different WTG models were evaluated by Everun’s Asset Management team, in order to improve the output from the sites from both a financial and planning perspective. 

An investment proposal was developed which identified the most appropriate WTG model, evaluating the potential project cost, financial return and the planning environment specific to each site. The asset owner(s) approved the repowering recommendation to replace the Vestas V29 on a 30m tower with a Vestas V39 on a 40m tower. 

To accommodate the increased dimensions of the new model, Everun’s planning team submitted and successfully gained planning approval in order to install and commission a larger WTG.  

The amendment application included: 

  • Shadow Flicker Assessment
  • Visual Impact Assessment
  • Noise Assessment
  • Bat Survey

A project delivery plan was developed which covered all the requirements to acquire and install the replacement WTGs. The Everun team sourced and managed the refurbishment of suitable WTGs. The refurbishment included an overhaul of all major components including the gearbox, generator, main bearing, yaw system and blades. 

In order to facilitate construction, the access lane to the site was improved, crane base extended, and the original foundation base removed. A foundation bespoke to the in-coming turbine was designed and installed in its place. 

Everun managed and carried out all the construction elements of the repowering project including decommissioning and disposal of the original WTGs, installation of the repowered WTGs along with reconnection and commissioning. 

The build phase for both the Greenhall and Waterside projects were completed in April 2021 with a total downtime of 10 weeks, associated with decommissioning, turbine removal, civil works (including a 4 week foundation curing period), installation and commissioning. Careful planning of each of the build components ensures downtime is minimised. 

Everun also manages the compliance requirements associated with a repowering project.  

This includes the DNO (Distribution Network Operator) repowering application process. Where an application is submitted to the DNO, NIE Networks, specifying the technical details associated with the replacement model. NIE Networks then carry out a review of the current connection characteristics to ensure compliance with the Connection Agreement can be maintained. An updated Connection Agreement is required for each repowering project. The OFGEM accreditation is also required to be amended to update the WTG model.  

Experienced in-house experts ensured a quick turnaround on the amendment, which for the Greenhall and Waterside site, was successfully approved within 7 weeks.