Siemens Energy Project Walpole - 400kV Synchronous Condenser
This case study focuses on the electrical works undertaken for the new 400kV Synchronous Condenser facility at Walpole, UK. This critical infrastructure project, initiated by Conrad Energy and supported by National Grid ESO, is a cornerstone of the UK’s strategy to enhance grid stability and facilitate the integration of more renewable energy sources into the national electricity network as we transition towards net-zero carbon emissions.
Project Overview
Traditional power generation methods inherently provide ‘inertia’ and ‘short-circuit level’ crucial for grid resilience. With the rise of intermittent renewables like wind and solar, these vital services need to be actively managed. The Walpole project addresses this by deploying 400kV synchronous condensers, supplied by Siemens Energy. These large rotating machines do not generate power but are essential for:
Providing reactive power
Maintaining stable voltage levels across the grid.
Enhancing grid stability
Absorbing or supplying reactive power as needed during demand fluctuations or system disturbances.
Contributing to system inertia and short-circuit level
Crucial for the grid’s operational integrity and resilience against faults.
Located adjacent to the existing Walpole 400kV substation, this facility is a key component of National Grid ESO’s ‘Stability Pathfinder’ initiative, designed to ensure a robust and reliable electricity supply in a rapidly decarbonizing energy landscape. The project commenced construction in Q3 2023 and is expected to be fully operational by 2025.
Scope of Work
The primary objective of our scope of works was to carry out the comprehensive installation of electrical and mechanical HVAC systems across the Walpole site. Our detailed involvement ensured the seamless integration and functionality of all necessary power, lighting, safety, and environmental control systems crucial for the synchronous condenser’s operation. This extensive scope included:
HVAC Systems
Environmental control and ventilation
Electrical Systems
Core power distribution and safety systems
Testing & Documentation
Commissioning, training and maintenance manuals
Our Contribution: Comprehensive Electrical Works
Our involvement in this project encompassed the full spectrum of electrical installations, ensuring the seamless operation and integration of this vital facility. Our scope of work included, but was not limited to:
Power Systems
- Sub-mains distribution & distribution boards
- Earthing and bonding
- Small power and wiring accessories
- Plant alarm marshalling
Lighting Systems
- General lighting
- Emergency Lighting / Luminaires
- External lighting
Environmental Control
- Air conditioning DX Split Systems
- Air conditioning Upflow Systems
- Battery room extract ventilation
- Electric heating systems
This case study will delve into the challenges, methodologies, and successes encountered during the execution of these critical electrical works, highlighting our role in bringing this significant energy infrastructure project to fruition.
Detailed Scope of Works
Power Distribution
Sub-mains distribution & distribution boards:
Designing and installing the core power distribution infrastructure.
Earthing and bonding:
Implementing robust earthing and bonding systems for safety and equipment protection.
Lighting Systems
General lighting:
Installation of internal general illumination throughout the facility.
Emergency Lighting / Luminaires:
Providing essential emergency lighting systems to ensure safe egress. For enhanced reliability we installed an intelligent central battery system.
External lighting:
Installing external lighting for site security and operational visibility.
Safety and Security
Specialist ATEX area:
The battery room installation was all ATEX zone 2. This was all installed and certified by our in-house team as part of our scope. This included lighting, heating ventilation and Fire Alarm
Fire alarm system:
Implementing a comprehensive fire detection and alarm system for site safety.
Containment systems:
Installation of cable containment systems, including trays, ladders, and conduits.
Plant alarm marshalling:
Setting up the system for collecting and consolidating plant alarms.
Roxtec Frames:
Installation of specialized cable and pipe sealing solutions (Roxtec) to seal cable ways and prevent ingress of moisture and the escape of gasses from ATEX areas.
Environmental Control
Air conditioning DX Split Systems:
Installing direct expansion (DX) split air conditioning systems for cooling for critical plant and within control rooms.
Air conditioning Upflow Systems:
Deploying upflow air conditioning systems. The Airdale System in the Syncon Hall has 3 upflow cooling units to provide the required cooling duty and a fourth unit is provided to give redundancy for the critical plant.
Battery room extract ventilation:
Implementing specialized ventilation for battery rooms to manage hydrogen gas and heat.
Electric heating:
Panel heaters, fan heaters, and battery room heaters for various heating requirements including ATEX areas.
Commissioning & Documentation
Inspection, testing and commissioning (Electrical & Mechanical HVAC):
Performing rigorous inspections, testing, and commissioning for all electrical and mechanical HVAC installations to ensure compliance and operational readiness.
Record documentation, training, O&M manuals:
Compiling comprehensive record documentation, conducting necessary training for site personnel, and preparing detailed Operation & Maintenance (O&M) manuals for future reference.
Project Management
Managing all preliminary site setup and coordination activities essential for the project.
Aconex Management Software:
For this project, we embraced and successfully integrated our workflows with the customer’s preferred project management software, Aconex, enabling seamless information exchange and collaboration.
Project Challenges and How They Were Overcome
Identify Challenges
Recognizing potential obstacles early
Collaborative Solutions
Working with all stakeholders
Implement Resolutions
Executing effective solutions
While the Walpole project ran smoothly overall, we did encounter a few specific challenges that required proactive management and collaborative solutions.
Overcoming Specific Challenges
Restricted Area Access
One of the main challenges we faced was managing access and coordinating our work within specific restricted areas on site. The presence of other ongoing projects in these work areas meant we had to implement strict controls over who could enter and what activities they could perform. This was crucial for maintaining safety and avoiding disruption to the overall project, not just for PCS but other contractor’s working on site.
Solution
We effectively managed this through diligent daily site coordination meetings. These regular meetings were instrumental in fostering clear communication, meticulous planning across all teams, and timely resolution of access conflicts, ensuring that our operations proceeded efficiently without compromising safety or other contractors’ progress.
Overcoming Specific Challenges
Long Lead Time Components
Another challenge arose due to the long lead time for the bespoke 3-compartment trunking, which was manufactured to order. This delay that was out of PCS hands posed a potential risk to the project schedule, as these critical components were integral to our electrical containment installation.
Solution
To mitigate this, our team engaged in close collaboration with other contractors on site. By collectively reviewing the project schedule and identifying interdependencies, we were able to adjust our work areas and strategically focus on tasks that did not immediately require the trunking. This flexible approach allowed continuous progress to be maintained on other electrical installations, preventing major delays and keeping the project on track.
Safety Stand-Downs and Support Provided
Safety Concern Identified
Siemens Energy initiated a site-wide safety stand-down
Proactive Response
Our team provided crucial support
Work Resumed Safely
Project continued with improved safety protocols
Enhanced Safety Measures
Erection of a new, enhanced site barrier system
Safety was paramount on the Walpole project, a principle we fully endorsed and actively contributed to. Early in the project, Siemens Energy initiated a site-wide safety stand-down due to concerns raised by their Health & Safety team regarding overall site access protocols. This immediate action underscored the commitment to safety from all parties involved.
To help get the project back on track swiftly and safely, our PCS site team provided crucial support in the erection of a new, enhanced site barrier system. This proactive assistance demonstrated our commitment to safety beyond our immediate scope and directly enabled works to resume promptly and securely across the entire site.
Recognition for Safety Excellence
Team Members Recognized
Martin Last and Tom Camm received formal recognition
Prestigious Award
Health & Safety award for proactive approach
Safety Incidents
Perfect safety record maintained throughout
Furthermore, we are proud to highlight the exceptional dedication to health and safety demonstrated by our site personnel. Both Martin Last and Tom Camm were formally recognized by Siemens Energy for their outstanding supervision and unwavering commitment to health and safety on site. Martin, in particular, received a prestigious Health & Safety award for his proactive approach and consistently high standards. Their exemplary conduct significantly contributed to maintaining a safe working environment throughout the entire duration of this complex and critical infrastructure project.
Proven Expertise in Energy Infrastructure
- This case study of the Walpole 400kV Synchronous Condenser project clearly demonstrates PCS’s capability to successfully deliver large-scale, high value, complex energy infrastructure projects.
- Our comprehensive electrical and mechanical HVAC expertise, combined with our proactive problem-solving and unwavering commitment to safety, ensured the successful execution of critical works for this vital National Grid initiative.
- We are proud of our contribution to enhancing the UK’s grid stability and enabling the transition to net-zero.
Partner with PCS for Your Next Project
- We are eager to leverage our proven experience and dedication to excellence on your future energy infrastructure projects.
- Let’s discuss how PCS can help you achieve your project goals, get in touch today.









