Bryn Blaen Wind Farm

Case study 15252

Name of Client and Location: Njord Wind Limited / Natural Power
Project Value: £5.8 Million
Duration of the Project: Phase 1 Started: September 2017 Phase 2 Energisation: November 2019
Services: Electrical Infrastructure, Balance of Plant
Market Sector: Renewable Energy
Powersystems Fact: Powersystems your high voltage specialist partners – Powersystems Renewable Energy team have connected 27% of all U.K. land based wind farm generation

Bryn Blaen Wind Farm:

Powersystems were responsible for the design, installation, testing and commissioning of the electrical infrastructure associated with the construction of the 14.1 MW Bryn Blaen Wind Farm. The wind farm was designed to generate and export renewable electricity to the local area, with the capacity to generate enough energy to meet the demands for around 8,400 homes every year. The 6 No Enercon 2.35 MW wind turbines began exporting power to the grid in November 2019. As a trusted NERS accredited company with over 40 years’ experience, Powersystems were appointed to assume the responsibility for the electrical and mechanical Balance of Plant for the wind farm, including an onsite substation for the wind farm and a substation at the point of connection for WPD.

Bryn Blaen Wind Farm

Major design considerations:

This site for wind turbines on the land north of the village of LLangurid in Powys was carefully considered. A number of factors needed to be justified in the development of the initial proposal, these included; low population density, wildlife and its use of the area, including the breeding territories of birds, and foraging paths of bats, accessibility of the site, local, regional and national planning policy as well as wind speeds. Approximately 7 km of new tracks were required to access the turbine locations. The tracks needed to be a minimum of 5 m wide, considering junctions, bends and passing places and at turbine base locations where wider working areas were required. Local materials were imported from nearby quarries for this construction. 

The major items of electrical plant that Powersystems designed, supplied, installed, and commissioned were:

  • Design of a new 66 kV substation/compound for the client and DNO to connect to the local 66 kV network
  • Design of new 66/33 kV Substation/compound and onsite electrical distribution
  • Supply and install 66 kV equipment for the compounds, inc. circuit breakers, dis connectors, etc
  • Design, Supply and install a 66/33 kV 20 MVA Transformer
  • Supply and install of a 2 panel 33 kV switchboard
  • Design and build transformer protection panels
  • 66 & 33 kV Cabling and terminations
  • All necessary building fit-out works comprising lighting and small power with intruder and fire alarm systems
  • Install low voltage, control, signal and communications cabling works
  • Full installation test and commissioning


Project facts and figures:

  • Number of generators: 6
  • Generator capacity: 2.35 MW
  • Totalled Installed capacity: 14.1 MW
  • Windfarm Voltage: 33 kV
  • Connection Voltage: 66 kV
  • Altitudes of site: 1200ft
  • Length of onsite 33 kV cabling: 6 km
  • Length of offsite 66 kV cabling: 13 km
  • Powersystems are a Lloyds registered (NERS) approved independent connection provider (ICP)
Bryn Blaen Wind Farm

Powersystems partnerships:

The wind farm site is located just off the A470 near LLangurig in Powys, mid-Wales with the point of connection substation being located near to Rhayader. The site and substations were constructed in partnership with Jones Bros Civil Engineering on behalf of the client, Njord Wind Energy. Local resource was used where possible. The employment of a local resident for the role of Powersystems Site manager and a local haulage company was used to assist with the cable installation works.

Bryn Blaen is one of a number of wind farms that have been developed in Wales over the last few years, helping to introduce clean, renewable energy, utilising the countries natural resources which is helping to combat climate change and secure our energy requirements within the UK.

The site connects onto the Western Power Distribution’s 66 kV electricity network via a radial, which in turn supplies a ring circuit that feeds Brecon, Builth Wells, Glasbury and Llandrindod wells.  Our engineers have the much-needed experience of working with every Distribution Network Operator across the UK on ICP projects, helping customers connect this type of project up and exporting to the grid at both 11 kV, 33 kV, 66 kV and 132 kV.

Bryn Blaen Wind Farm Turbine Substation:

Bryn Blaen Wind Farm Turbine Substation and compound was built on the wind farm to feed the turbines. The substation building includes; a HV switch room, scada room, meter room, store room and a bathroom. The HV Switch room has a 33 kV 2-panel switchboard consisting of an incomer and a wind farm feeder circuit breaker. The substation compound consists of a busbar system, 66 kV disconnectors, 66 kV circuit breaker and a 20 MVA 66/33 kV Transformer. The compound also includes a 33 kV earthing auxiliary transformer, neutral earthing resistor, 4.4 MVAr reactor, 4.4 MVA harmonic filter and a 33 kV filter resistor. The substation building has a permanent LV supply from the auxiliary transformer located in the substation compound.

Bryn Blaen Wind Farm Generation Substation:

Bryn Blaen Wind Farm Generation Substation and compound was built next to an existing substation (Bryn Titli) in order to allow WPD to connect to the local 66 kV network. The substation building includes a client switch room, WPD switch room and a meter room. The substation consists of a WPD compound and a wind farm feeder compound. The WPD compound consists of a 66 kV busbar system, 2 No 66 kV disconnectors, 66 kV VT’s and a 66 kV circuit breaker. The wind farm feeder (client) substation compound consists of a 66 kV busbar system, 2 No 66 kV disconnectors, 66 kV VT’s, 66 kV 5.5 MVAr Reactor, a 66 kV cable frame and a 66 kV circuit breaker.

A GRP has been installed between the Bryn Blaen Wind Farm Generation Substation and the existing Bryn Titli substation from where the LV 230 V mains will supplied and LV metering installed. The new substation building has a permanent LV supply from a separate mains grid connection but there is also the option as a back-up supply from a 100 KVA 66 kV/400V auxiliary transformer located inside the 5.5 MVAr reactor. The reactor is located in the substation (client) compound and will automatically transfer the LV supply in case of a mains failure via an auto change-over panel.

The earth mats for the Bryn Blaen Wind Farm Generation Substation and the existing Bryn Titli substation have been connected together due to the close proximity of the substations as advised from an earthing study. The Bryn Blaen Wind Farm Generation Substation and the Bryn Blaen Wind Farm Turbine Substation are connected by 13 km of 66 kV cable and a fibre optic cable.

Bryn Blaen Wind Farm

Bryn Blaen Wind Farm project timings:

Phase 1 Started: September 2017

Consisted of building the wind farm, turbine substation and 13km 66kV grid connection cable installation.

Phase 1 completion: January 2018


Phase 2 Started: September 2018

Consisted of building the WPD substation at the point of connection

Phase 2 completion: May 2019

Phase 2 Energisation: November 2019


What the client wanted:

Powersystems carried out the principle contractor role on phase 2 of the project at the request of the client. Powersystems were utilised as the conduit between the client and WPD in gaining design approval for the substation, connection works and receiving WPD sign off for the build.

Bryn Blaen Wind Farm

How Powersystems have helped:

Powersystems engineers were involved with the;

  • Interface with Western Power Distribution
  • Switchgear installation and commissioning
  • Transformer installation and commissioning
  • Cable design, supply & installation
  • HV testing
  • SAP provision
  • Backup generator supply

Design works

  • The introduction of reactors and harmonic filters were utilised from a design in order to comply with WPD connection agreement

Installation works

  • Installing 13km of 66kV cable with joint terminations every 500m alongside the A470 and through and existing wind farm had its challenges 

Commissioning works

  • Commissioning the wind farm to comply with the new G99 regulations required skilled and knowledgeable commissioning engineers

Energisation works

  • Powesystems proposed an energisation sequence that would be accepted by WPD

Environmental benefits

  • Renewable clean energy
  • Extensive management of sensitive upland habitats was taken place to create suitable habitats for important species of birds and to ensure the survival of upland plant communities that have been threatened by EU agricultural policy

Economic benefits

  • During construction, materials sourced from local suppliers where possible
  • Local companies/resource employed where possible
  • Wind farm could provide an annual payment of approximately £90,000 annually to be spent on community projects. This figure is based on £5000 per MW of capacity per year whilst in operation, creating a development fund of £2.25million.

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