20 MW Electrical Infrastructure Project High-voltage and LV power systems for a major Welsh energy-recovery facility
Project Snapshot
| Project Detail | Information |
| Client | CNIM |
| End User | Wheelabrator Technologies |
| Location | Parc Adfer, Deeside, CH5 2LL |
| Project Value | £1.2 million |
| Duration | Contract Award: July 2017 • Site Works: Feb 2018 • Energisation: Sept 2018 |
| Services | 33 kV & 11 kV HV Infrastructure, High‑Power LV Systems, HV Control & Protection |
| Market Sector | Energy from Waste (EfW) |
| Installed Capacity | 20 MW |
| Connection Voltage | 33 kV / 11 kV |
| Powersystems Role | Full HV/LV design, installation, testing and commissioning |
| Powersystems Fact | Powersystems has delivered high‑voltage infrastructure for multiple EfW, biomass and CHP plants across the UK, supporting decarbonisation and secure energy recovery solutions. |
Parc Adfer 20 MW EFW Case Study
Download the full Parc Adfer Case Study — ideal for engineers, developers and technical stakeholders. This summary outlines the 33 kV grid connection, 11 kV distribution, transformer installation, protection design and full commissioning delivered by Powersystems for the 20 MW Parc Adfer Energy from Waste facility. It also highlights the HV/LV integration, SCADA systems, and engineering partnership between Powersystems and Mitsubishi that enabled successful delivery. The full document provides deeper insight into the design methodology, electrical interfaces and commissioning strategy behind one of Wales’ most significant energy‑recovery infrastructure projects.
Client & Site Background
Wheelabrator Technologies was awarded the contract to build and operate Parc Adfer, a major Energy‑from‑Waste facility serving the North Wales Residual Waste Treatment Partnership (NWRWTP) — a collaboration between five Welsh local authorities.
The plant supports Welsh Government objectives to achieve 70% recycling and ≤5% landfill by 2025, recovering metals, recyclables and energy from post‑recycled waste.
The Challenge
CNIM, the EPC contractor, required a specialist electrical engineering partner capable of delivering:
- A 33 kV DNO connection
- A 21/25 MVA 33/11 kV power transformer
- High‑power LV distribution
- A Mitsubishi 7‑panel 11 kV switchboard
- Auxiliary transformer installation
- HV control, protection and SCADA integration
- Full HV/LV testing, commissioning and energisation
The facility required highly reliable electrical infrastructure to operate the 20 MW steam turbine, auxiliary plant and standby generation systems.
Our Engineering Solution
Powersystems, working in partnership with Mitsubishi Europe, delivered the entire HV and LV electrical infrastructure, including:
- 33 kV cable circuit from the DNO metering substation
- 21/25 MVA 33/11 kV transformer with on‑load tap changer
- Installation and commissioning of the Mitsubishi 7‑panel 11 kV withdrawable switchboard
- Installation of 4 cast‑resin auxiliary transformers (3150 kVA & 2500 kVA)
- 11 kV circuits to the 20 MW turbine generator and standby generator
- HV and LV protection systems, including bespoke transformer protection panels
- Complete control, signalling and communication infrastructure
- Full testing, commissioning and energisation
Powersystems produced all detailed electrical designs and value‑engineered solutions to optimise equipment selection and network configuration.
Project Process
- Early‑stage HV design, grid interface studies and value engineering
- Substation and power transformer design submissions
- 33 kV cable installation, terminations and commissioning
- Installation of 11 kV switchboard, auxiliary transformers and LV systems
- HV/LV protection design, relay configuration and SCADA integration
- Cable installation for turbine and standby generator
- Factory Acceptance Tests (FAT) & Site Acceptance Tests (SAT)
- Energisation, commissioning and handover
Project Facts & Figures
- Connection Voltage: 33 kV
- Primary Transformer: 21/25 MVA ONAN/ONAF 33/11 kV
- Switchgear: Mitsubishi 7‑panel 11 kV suite
- Auxiliary Transformers: 2 × 3150 kVA & 2 × 2500 kVA
- Generator Turbine Capacity: 20 MW
- Man‑hours Completed: >1 million without a lost‑time incident
Technical Specifications
High‑Voltage Systems
- 33 kV cable route and metering interface
- 33/11 kV power transformer with OLTC
- 11 kV switchgear (withdrawable pattern)
- Transformer protection panel (Powersystems‑designed)
- Generator incomer and ancillary HV feeders
Auxiliary & LV Systems
- Four cast‑resin LV transformers
- High‑power LV distribution
- LV control, marshalling and signalling
Control & Protection
- Full transformer and feeder protection schemes
- Integration with turbine protection systems
- SCADA and plant monitoring interfaces
Partnerships
This project marked the first major collaboration between Powersystems and Mitsubishi Europe, combining:
- Mitsubishi’s leading high‑voltage switchgear products
- Powersystems’ HV/LV design, installation and commissioning expertise
Their joint capabilities enabled the successful tender and delivery of a technically demanding EfW project.
Key Risks & Mitigations
- High‑power transformer energisation risk – Mitigation: Using detailed protection studies and staged energisation procedures.
- Complex coordination across a Tier‑1 EPC environment – Mitigation: Daily interface management with CNIM ensured safe, sequenced installation.
- Large‑scale construction site (1M man‑hours) – Mitigation: Robust H&S systems ensured zero lost‑time incidents.
- Integration of multiple HV/LV systems – Mitigation: Rigorous FAT/SAT processes and structured commissioning prevented incompatibility issues.
- Demanding client technical requirements – Mitigation: In‑house design team delivered compliant layouts, protection schemes and technical documentation.
Environmental Considerations
- Recovery of metals and aggregates, improving recycling rates by ~7%
- Diverting post‑recycled waste from landfill
- Reducing greenhouse gas emissions
- Renewable energy generation for 30,000+ homes
Economic & Social Value
- £51,000+ local community funding
- 35 permanent roles created
- Hundreds of construction jobs
- Long‑term PPP benefits for five local authorities
Future Prospects
The Parc Adfer Energy‑from‑Waste facility was delivered on time, to specification and on budget.
The project strengthened the Powersystems–Mitsubishi partnership, demonstrating shared technical capabilities and paving the way for future energy‑from‑waste and industrial power‑engineering projects.
Related Projects
- Sandall Stone BHEG Doncaster 66 kV
- Ripley Road Bradford (BHEG)
- New Earth Energy Avon mouth EFW
Powersystems deliver specialist high voltage solutions for Energy from Waste, CHP and industrial power projects throughout the UK.
Speak to our engineering team to support your next project.