Coryton BESS Development Project

Since early 2024, Arthian has supported our client, Green BESS Development Services (GBDS), on the substantial works required to facilitate the installation of a new 11-22MW (tbc) Battery Energy Storage System (BESS) adjacent to upper-tier COMAH sites. Our involvement is ongoing and includes a wide range of services relevant to our SPEN framework appointment.

The Arthian team delivered a full scope of project work for this client, covering multiple phases from demolition to hazard reviews.

1. Demolition of Storage Tanks

• Preparation of a Pre-Construction Information (PCI) package for tendering to demolition contractors, including site walkover, reconnaissance, and engineering review of existing site infrastructure.

• Production of demolition drawings highlighting scope, access, and laydown requirements.

• Swept path analysis for site access planning.

• Detailed Demolition Scope of Works, covering:

  • Defined scope and extent of demolition.

  • Proposed construction sequence.

  • Client safety and site protocols.

  • Required documentation and contractor deliverables.

  • Isolation and clean-down requirements.

• Coordination of site visit with demolition contractor to refine demolition strategy and outline programme.

2. New Workshop Building

RIBA Stage 1 – Preparation & Briefing

• Develop and refine GBDS’s requirements with stakeholders.

• Assess availability and capacity of existing utilities (drainage, power, telecoms, water).

• Deliver a RIBA Stage 1 Briefing Report outlining building function and design intent.

• Collate existing site data and produce PCI documentation for the new build.

RIBA Stage 2 – Concept Design

• Architectural concept and layout design based on Stage 1 findings.

• Development of a temporary workshop scheme.

• Produce a Basis of Design report for civil and structural elements.

• Civil and structural scheme design, including:

  • Blast-resistant structural performance.

  • Overhead gantry crane integration.

  • External works (drainage, hardstanding, road tie-ins).

  • Re-use of existing foundations/pile caps where feasible.

• Generate scheme-level drawings and specifications.

• Designer’s Risk Assessment (DRA).

• Geotechnical and geoenvironmental desk studies.

3. Existing Workshop – Demolition & Modifications

RIBA Stage 1 – Preparation & Briefing

• Site walkover, reconnaissance, and engineering review.

• Stakeholder engagement to define demolition and modification requirements.

• Review utilities and identify necessary alterations.

• RIBA Stage 1 Briefing Report with scope and requirements.

• PCI documentation preparation.

RIBA Stage 2 – Concept Design

• Architectural concept layout for modifications.

• Basis of Design report for civil and structural works.

• Scheme design for required structural modifications.

• Define scope for modifications to building services (fire, power, lighting, telecoms, water).

• Scheme drawings, specifications, and DRA.

• Supporting geotechnical/geoenvironmental studies.

4. Supplementary Scope of Works

• Planning support and drawings for GIS Building and enlarged stores.

• Production of Heads-of-Terms drawings, including lease areas, site/CDM boundaries.

• Storage optimisation study, with moveable racking assessment.

• Site inspection to verify storage and dimensions for alterations.

• Order of Magnitude (OOM) cost estimate for all construction activities (+/- 50%).

Tank Inspections & Clean-Down Preparation

• Structural inspection of tank access ladders.

• Dip level measurements of residual volumes.

• Sampling and testing of materials for cleaning scope.

Drainage Study

• Review of existing arrangements and constraints.

• Identification of planning considerations (climate change allowances).

• Establishment of permeable/impermeable areas and runoff calculations.

• Outline SuDS treatment strategy and preliminary network design.

• Feasibility report with conclusions and recommendations.

5. Site Surveys & Ground Investigation

• PAS 128 Topographical and Utilities Survey for BESS site and cable route.

• Ground Investigation for Cable Route and Coryton Power Station.

• Principal Designer Role during tender and GI phases.

• Contractor tendering, selection, and supervision.

Geotechnical Reporting

• Interpretative Geotechnical Investigation Report (GIR) for new GIS Substation:

  • Ground and groundwater profiling.

  • Soil parameter derivation.

  • Pile recommendations.

  • Exploratory hole plan and cross-sections.

  • Risk assessment.

• Technical Note on GI and pile testing for New Store Building.

• Combined Geotechnical & Geo-environmental GIR for 400kV cable route:

  • Ground profiling and waste classification.

  • HDD feasibility and resistivity testing.

  • Cross-sections and exploratory hole plan.

  • Geotechnical risk assessment.

6. Geo-environmental Reporting

• Phase 2 Generic Quantitative Risk Assessment (GQRA) for GIS Substation, including ground gas risk.

• Waste Classification Report for Store Building.

7. COMAH Hazard Review for BESS Development

Scope of Consideration

• HSE consultation zones around COMAH facilities.

• Thermal radiation and fire event modelling.

• Overpressure risks from pipelines.

• Vulnerability assessment of infrastructure.

• Cost-benefit review of mitigation measures.

Deliverables

• Review of COMAH risks and hazard impacts.

• Vulnerability assessment for site operatives.

• Evacuation vs shelter-in-place strategies.

• Fire Hazard Appraisal (FHA) for BESS site.

• Recommendations for mitigation and risk reduction.

• Final summary report and close-out meeting.