Operating as the Engineer, Procure and Construction (EPC) contractor, we were responsible for the delivery of all civil and electrical design and build elements associated with the Bumpers Battery Energy Storage System (BESS) & connection, the joint largest BESS in Europe at it’s time of completion.

Scope of Works

The scope of work was broad and all-encompassing, consisting of every element required to construct a 100mW Battery Storage solution connected to the Grid. Key sections of our delivery included the design and construction of two 50mW Battery Storage solutions, each with a 132kV substation connection.

We provided all the work required to design, construct, install, and commission each phase of the BESS systems, including extensive ducting systems and multicore cabling. The scheme’s key requirement and achievement was the concurrent delivery of both 50mW phases and their respective 132kV connections.

Our broader range of services encompassed several key activities, including:

• Underground/Overground Cabling, Earthing, Ducting and Drainage
• Installation of Current Transformers/Voltage Transformers (CTs/VTs)
• Installation and commissioning of132kv – 33kV Transformers
• ICP 11kV Distribution Transformer
• All equipment foundations, beams and plinths
• Site erosion control
• Temporary access road
• Permanent bell mouth junction works
• Temporary works & traffic management
• Cable jointing & pulling
• Commissioning of; Interface, switch rooms, transformers and cabling
• DNO interface
• All telecommunication, metering, and protection and control.

Efficient Access Planning

Due to the challenging project programme, throughout the project, Kier, Morrisons, and UKPN worked in proximity within the constructed 132kV substation compounds. The confined nature of the compounds caused logistical difficulty due to the scale of the respective resources required. At peak, up to 80 personnel were undertaking work within each compound.

Collaborative planning was essential in providing efficient access planning and delivery to key dates, mitigating potential delays and health and safety issues.

The sessions targeted workstreams and trades, looking forward 8-10 weeks and backward planning from key milestones to remove identified constraints. This led to efficient access to the site by all parties and ultimately achieving challenging project milestones.

Briefing sessions were held every morning, allocating sections of the site to prevent overlap between work fronts. These morning briefings assisted in coordinating all delivery teams across the site and informed all their requirements and access, removing potential overlap between contractors and site staff.

Key Challenges and Solutions

Project Programme

The primary challenge encountered on the Bumpers Farm 100mW BESS was the requirement to meet an 8-month programme, delivering a 132kV substation per each 50mW phase of the project.

Due to the nature of the programme, which was working on a condensed project footprint, we undertook highly detailed programme management and efficient access planning, ensuring each work front could progress efficiently without impacting subsequent works.

EPC Contract

Keltbray Infrastructure undertook the delivery of the project as the Engineer, Procure & Construct (EPC) contractor. Despite being an experienced turnkey contractor, the Bumpers Farm scheme presented unique challenges throughout delivery. We used an integrated approach, coalescing individual business units to apply specialist expertise across the project, including:

• Civils Design Wentworth House Partnership
• Electrical Design, Installation & Commissioning Keltbray-IDEC,
• Civil Engineering Group Highways Division
• Electrical Engineering & EPC management Group Energy Division

We used internal systems to facilitate interfaces and ensure adherence to project milestones. Information sharing was paramount, and this was achieved through a Common Data Environment accessible to all. This provided direct benefits to the client through expedited governance, resulting in swift mobilisation, planning, and delivery.

Interface between Project Stakeholders

Regular progress and coordination meetings with the client were help to discuss work durations, work programmes, accessibility, deconfliction, and delivery updates. These meetings were held weekly and daily during busy periods to streamline delivery and mitigate delays.

Additionally, we interfaced with the local Council to coordinate the use of a layby as the main site access point, attending Parish Council meetings to ensure they had no objections to our proposed delivery methods and traffic movements.

We also established agreements with local landowners to use their property for storage and welfare facilities. We held regular meetings to inform them of project progress and projected timescales and respond to any questions. Landowners were also able to provide criteria for returning the land to its original state upon completion of the project.

Logistical Navigation with Stakeholders

All alliance members (Kier, Morrisons & UKPN) required access to each 132kV compound at the same time. This meant that up to 80 personnel were working on each platform concurrently. We undertook extensive access planning through numerous collaborative planning sessions to remove potential constraints and provide each contractor with clear objectives and time frames.

Additionally, the site was in the path of overhead electrical wires. Therefore, we required additional interfacing with the Distribution Network Operator (DNO) to establish clearances and restrictions. Barriers and height restrictors were used to prevent plant and machinery from operating near overhead wires, and any change to this equipment required consultation from the DNO to verify safety.

Our Senior Authorised Person maintained phone and email contact with the DNO to raise any such approaching requirements, and copies of equipment inspections were submitted to the DNO regularly. By maintaining regular contact and forecasting requirements, we mitigated any delays caused by the DNO’s verification process.

Value Engineering and Innovation

Throughout the design and construction, we delivered more than £200k in savings through value engineering and innovation.

• Working closely with Wilson Transformers to engineer a Natural Earthing Resistor (NER), which provided a cost saving of approx. £40k per substation, (£80k), to the client.
• Rationalising each battery Mega Pack base from multiple foundations into a single entity, reducing shuttering, resourcing, and the volumes of concrete required, providing approximately £100k in savings while simultaneously reducing the programme.
• Using extensive multidisciplinary wiring in place of individual wiring runs, removing a significant amount of cabling work. We used 27 multicore cables, which subsequently yielded around £50k cost savings.