Delivering a complete grid‑connected battery storage facility supporting Scotland’s renewable future
Project Snapshot
| Client | FIELD Energy |
| Location | Fort Augustus, PH32 4BT, Scotland |
| Project Value | £9.3 million |
| Project Duration | Oct 2023 – Oct 2024 (SSEN energisation April 2025) |
| Market Sector | Battery Energy Storage Systems (BESS) |
| Services Delivered | Full Civil & Electrical Balance of Plant (EBoP) |
| Powersystems Fact | Powersystems is a specialist UK HV engineering contractor delivering grid connections and infrastructure for battery, wind and solar generation for over 49 years. |
Auchteraw Battery Case Study
Download the full Auchteraw BESS Case Study to explore how Powersystems delivered the complete civil and electrical Balance of Plant for this 50 MW / 100 MWh grid‑scale battery installation in the Scottish Highlands. The PDF provides a clear overview of our battery bay construction, transformer and PCS installation, 33 kV infrastructure, SCADA integration and full commissioning works leading to SSEN energisation. Ideal for engineers, developers and energy professionals seeking deeper technical insight into a major BESS project that enhances grid stability, supports renewable integration and strengthens Scotland’s pathway to net‑zero.
Client & Site Background
Auchteraw BESS is a 50 MW / 100 MWh grid‑scale battery installation located near Fort Augustus in the Scottish Highlands. Developed by FIELD Energy, the site plays a critical role in stabilising the transmission system north of the B4 boundary, enabling storage of surplus renewable generation and releasing energy when required.
The project includes 14 battery bays, each with 22–24 CATL cubes, dedicated PCS units and transformer skids, providing a total capacity of 61.6 MVA. The completed installation connects directly into the Fort Augustus 400 kV grid substation, strengthening flexibility and supporting the UK’s transition to net‑zero.
Powersystems acted as Principal Contractor under CDM, delivering the complete Civil and Electrical Balance of Plant.
The Challenge
The Auchteraw project presented unique engineering and environmental challenges:
- Delivering a complete civil and electrical package in a remote Highland location
- Working under severe weather constraints during winter conditions
- Managing delivery, handling and installation of over 300 battery cubes
- Coordinating multi‑contractor interfaces and international logistics
- Achieving full SSEN grid compliance and managing energisation delays
- Maintaining high standards of environmental care and noise mitigation
Powersystems’ experience in HV and BESS delivery was instrumental in overcoming these challenges safely and efficiently.
Our Engineering Solution
Powersystems delivered a full turnkey Civil + EBoP solution, including:
Civil Works
- Public road improvements and widening
- Construction of new access roads and turning areas
- BESS compound development, drainage and foundations
- Brick‑and‑block DNO building
- Containerised welfare compound with EV charging
- 4 m acoustic fencing
- Landscaping and reinstatement
Electrical Balance of Plant
- 33 kV switchroom with 16‑way switchboard
- Installation of 316 CATL battery cubes
- PCS units and 14 transformer skids
- LVAC systems, metering and protection
- SCADA integration and fibre‑optic communications
- Full HV earthing system
- Auxiliary transformer and backup supplies
- CCTV, alarms, control wiring and small‑power systems
Principal Contractor Responsibilities
- CDM management and site safety leadership
- All civil & electrical subcontractor coordination
- Daily HSEQ briefings and documentation
- Logistics planning and delivery management
Project Process
- Oct 2023 — Site mobilisation and start of civil works
- May 2024 — First CATL battery cubes delivered (300+ installed within 5 weeks)
- Jul 2024 — DNO building completed and accepted; PCS and transformer deliveries
- Aug 2024 — 33 kV & LV cable installation complete; VLF cable testing
- Aug 2024 — Cold commissioning of BESS equipment
- Oct 2024 — Hot commissioning and system testing complete
- Oct 2024 — Takeover Certificate issued
- Apr 2025 — SSEN energisation of 33 kV connection
Project Facts & Figures
- 14 battery bays, each with 22–24 CATL cubes
- 50 MW / 100 MWh capacity
- 61.6 MVA installed capability
- 316 battery cubes installed
- 33 kV switchroom with 16 circuit breakers
- SCADA, LVAC, CCTV, metering & backup systems
- 4 m acoustic fencing for noise attenuation
- NERS‑accredited ICP delivery
Technical Specifications
Electrical Infrastructure
- 33 kV switchroom with 16‑way switchboard
- Transformer skids and PCS units per battery bay
- LVAC systems and backup supply
- Grid metering and protection packages
- Earthing grid for substation and battery areas
- Fibre‑optic communications network
- SCADA interface with FIELD Energy and SSEN
Buildings & Facilities
- Brick‑and‑block DNO building
- Control Room with SCADA, LVAC, CCTV, battery backup and metering
- Containerised welfare with EV charging
- Specialist acoustic boundary fence
Partnerships
- FIELD Energy — Client
- R.J. McLeod — Civil engineering partner
- Powersystems — Principal Contractor (Civil + EBoP)
- SSEN — Grid connection provider
Key Risks & Mitigations
- Severe winter weather – Mitigation: Daily weather reviews, snow/ice equipment on standby, maintained safe access routes.
- Grid‑connection delay – Mitigation: Retained small technical team on site; proactive coordination with SSEN.
- Battery safety – Mitigation: Advanced fire‑suppression design and monitoring, strict isolation procedures.
- Road access & logistics -Mitigation: Traffic plans, road upgrades, off‑loading strategies and controlled deliveries.
- High packaging volumes – Mitigation: Additional waste segregation; rapid deployment of extra skips.
Environmental Considerations
- Full EIA and ecological surveys (otters, badgers, bats, newts)
- Dust, noise and waste‑management controls
- Acoustic fencing and landscaping to reduce visual and noise impact
- Efficient plant movements to reduce fuel usage
- Supports increasing renewable penetration into the grid
Economic & Social Value
- Strengthens local supply chains through regional contracting
- Uses local labour, materials and accommodation where possible
- Enhances grid resilience, reducing constraint costs
- Supports reduction of peak‑demand energy prices
- Provides long‑term operational employment
Future Prospects
Successful delivery of Auchteraw BESS led FIELD Energy to award Powersystems a subsequent project, marking the start of a long‑term partnership.
The site now plays a vital role in Scotland’s ability to store renewable energy and support a stable, resilient and decarbonised grid.
Related Projects
- Ray Wind Farm 20 MW Co-located Battery
- Greener Grid‑Stability Projects
- Coylton BESS 275 kV Project
- Grid Stability & Flexibility Installations
Delivering a grid connected BESS or major flexibility project?
Speak to Powersystems for complete BESS Electrical Balance of Plant, including HV design, installation, protection, SCADA and full commissioning.