
High‑voltage engineering and grid connection for a 35 MW onshore wind farm in Yorkshire
Project Snapshot
| Project Detail | Information |
| Client | RWE / Innogy Renewables |
| Location | Goole, East Riding of Yorkshire |
| Project Value | £4.8 million |
| Project Duration | Commissioned June 2016 |
| Services | 33 kV Electrical Balance of Plant, 66 kV Grid Connection, HV Infrastructure |
| Market Sector | Renewable Energy – Onshore Wind |
| Installed Capacity | 35 MW |
| Powersystems Role | HV design, installation, testing, commissioning, grid connection works |
| Powersystems Fact | The Powersystems Renewable Energy team has connected 24% of all UK land‑based wind generation, making us one of the most experienced HV wind engineering companies in the UK. |
Goole Fields II 35 MW Wind Farm Case Study
Download the full Goole Fields II Wind Farm Case Study — ideal for engineers, developers and technical stakeholders seeking detailed insight into the delivery of a 35 MW onshore wind farm in Yorkshire. This summary provides an overview of the full 66 kV grid connection adopted by Northern Powergrid, the 33 kV Electrical Balance of Plant serving 17 Senvion MM92 turbines, and the advanced point‑on‑wave switching solution engineered by Powersystems to ensure compliance with Engineering Recommendation P28 by mitigating transformer inrush currents during energisation.
Client Background
RWE (formerly Innogy) is one of the UK’s major renewable energy developers. Goole Fields II forms part of the wider Goole Fields Wind Farm cluster in East Yorkshire, extending the original site from 16 to 33 turbines and increasing the combined generation capacity to over 67 MW.
Goole Fields II contributes significantly to regional renewable power generation, producing clean energy equivalent to the electricity needs of 22,100 UK homes, with both wind farms together supporting the equivalent consumption of 38,000 homes.
The Challenge
Innogy required a complete 66 kV to 33 kV electrical infrastructure solution for the 17‑turbine extension, including:
- A new 66 kV grid connection to Northern Powergrid
- Integration with the existing Goole Fields Wind Farm electrical network
- A design that complied fully with Engineering Recommendation P28 for voltage disturbances
- EBoP infrastructure for 17 Senvion MM92 turbines
- Secure, vandal‑resistant external package substations
- A reliable communication and SCADA interface
Early design studies identified that the 39 MVA 66/33 kV transformer would cause unacceptable voltage dips (14.9%) during energisation—far exceeding the 3% P28 limit. This required a robust engineering solution to mitigate inrush current and maintain grid stability.

Our Engineering Solution
Powersystems delivered the full Electrical Balance of Plant (EBoP) and grid connection, including:
- A 66 kV outdoor open‑terminal substation
- Adoption‑ready infrastructure for Northern Powergrid
- A 39 MVA 66/33 kV grid transformer with protection systems
- A point‑on‑wave switching controller to reduce transformer inrush current
- 17 33 kV turbine package substations with anti‑vandal housings
- Remote control and monitoring for all substations
- 32 km of 33 kV underground cabling and fibre networks
- Full grid compliance studies, protection settings and modelling
This ensured safe energisation of the transformer within P28 limits, reliable turbine operation, and resilience across the full 35 MW export capacity.
Project Process
- Early‑stage electrical design, studies and grid modelling
- HV substation layout development and P28 mitigation engineering
- Installation of 66 kV plant, transformer, switchgear and ancillary systems
- Cable installation — 66 kV connections, 33 kV turbine circuits and fibre comms
- Construction of 17 external 33 kV package substations
- Protection and control configuration, SCADA integration
- Grid compliance testing, energisation and commissioning
- Handover to Northern Powergrid and Innogy
Project Facts & Figures
- Turbines: 17 Senvion MM92
- Individual Turbine Rating: 2.05 MW
- Installed Capacity: 35 MW
- Grid Transformer: 39 MVA 66/33 kV
- POW switching installed: Yes (P28 compliance)
- 33 kV Cable Installed: 32 km
- Grid Connection Voltage: 66 kV
Technical Specifications
66 kV Infrastructure
- ABB Pass Unit with circuit breaker, VTs, disconnectors & earth switches
- 66 kV cable sealing ends
- Outdoor open‑terminal substation
- 66 kV control & protection panels (including AVR & point‑on‑wave controller)
33 kV & Auxiliary Systems
- 17 external package substations with anti‑vandal protection
- 33 kV switchgear, protection and control
- 2.5 MVA 33/0.69 kV turbine transformers
- 33 kV neutral earthing resistor (NER)
- Auxiliary transformer circuit breaker
- 110 V DC charger and battery systems
- SCADA signal and communication wiring
Design & Grid Compliance
- P28 voltage disturbance analysis
- Insulation coordination study
- Lightning protection study
- Earthing system design
- Grid compliance studies for transformer and turbine integration
Partnerships
The Goole Fields II extension was delivered collaboratively with:
- Innogy / RWE — Client
- Farrans Construction — Civil & Principal Contractor
- Northern Powergrid (NPG) — Grid adopting authority
This strong partnership ensured smooth delivery, full regulatory compliance and adoption of the new 66 kV connection by NPG.
Environmental Considerations

- Total installed capacity of 35 MW reduces reliance on fossil fuels
- Clean generation equivalent to powering 22,100 UK homes annually
- Supports national decarbonisation targets
- Combined Goole Fields I & II output of 67 MW supports 38,000 homes
- Contributes to long‑term UK renewable energy security
Economic & Social Value

- £250,000 per year community fund contribution
- £1.61 million expected investment over wind farm lifetime
- Supports local employment and supply chain activity
- Enhances regional infrastructure and supports local regeneration plans
The Results
The Goole Fields II Wind Farm was successfully energised and fully operational in 2016.
The project delivered:
- Reliable 35 MW export capability
- Full P28‑compliant transformer energisation
- Seamless network integration with Goole Fields I
- A safe, high‑quality HV installation adopted by Northern Powergrid
It stands as a successful extension to the original Goole Fields site and a major contributor to sustainable power generation in Yorkshire.
Related Projects
- Camster II 36 MW
- Limekiln 108 MW
- North Kyle 212 MW
- Sandy Knowe 86.4 MW
- Douglas West 46.8 MW



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