Vyrnwy Frankton IEOI PQQ · UK public procurement notice

This Invitation for Expressions of Interest (IEOI) is issued by Green GEN Cymru Limited to seek expressions of interest for the provision of the Packages 1 - 4 for the Vyrnwy Frankton Project.

Th purpose of this document is to:

a) Inform the market of:

(i) The scope of services; and

(ii) An outline of the procurement process and timeline;

b) Invite parties to express their interest in participating in the Invitation to Tender (ITT) stage for each Package; and

c) Seek preliminary responses to a Pre-Qualification Questionnaire (PQQ) to derive a shortlist of Tenderers to be invited to participate in the ITT for each Package.

1.2 Project Background

The Green GEN Cymru portfolio, Vyrnwy Frankton, is to be serviced by a 132kV high-capacity double circuit connecting into National Grid Electricity Transmission (NGET) Network. The main line comprises overhead steel lattice tower. The Green GEN Cymru contracted generation connections will be made via a network of 132kV wood pole circuits, underground cables, switching and substations.

FEED contract is in place to provide the initial design detail and is being delivered by Stantec. The consultant is undertaking the Principal Designer role during the FEED contract phase; the Principal Design role will be transferred to the Detailed Designer.

1.3 Scope

1.3.1 Package 1 - Substations

The Vyrnwy Frankton electrical network comprises 7 distinct sites, which include:

• Switching Stations
• Collector Stations
• Transformer Substations

Several sites will incorporate:

• Reactive Power Compensation Systems
• Harmonic Filtering Equipment

The Contractor is expected to design, install, construct, and commission the following but not limited to:

Civil Works

• Site platforms and foundations
• Control buildings and auxiliary structures
• Internal / External Access roads
• Transformer Bund
• Cable troughs
• Surface / Foul / Oily water drainage (as required)
• Site Security
• Water Supply
• Fire Fighting Supply
• Flood Resilience (as required)
• Landscaping / screening (as required)
• Construction Compound

Primary Works

• High-voltage switchgear
• Power transformers
• Instrument transformers
• Busbars, disconnectors, and circuit breakers
• Reactive compensation units (e.g., capacitor banks, STATCOMs)
• Harmonic filtering equipment

Secondary Works

• Protection systems (relays, merging units)
• Control systems (SCADA, RTUs, PLCs, GPS clock)
• Building Management System (HVAC, lighting, security)
• Communication infrastructure
• Metering and monitoring systems

The switching/substation sites proposed for are indicated as follows:

Site Name

Lower Frankton Switching Station

Cors y Gareg Collector Station

Llyn Lort I Energy Park Switching Station

Rhiwlas Substation

Banc Du Energy Park Switching Station

Esgair Galed Energy Park Switching Station

Waun Hesgog Energy Park Switching Station

The Contractor is expected to establish temporary working areas to include construction compounds, laydown areas, parking and welfare facilities. The Contractor is expected to provide as-built records once construction is complete.

Package 2 - Tower line

The double circuits from the NGET points of connection into mid Wales are predominantly overhead, with steel lattice towers of the L7(c) design carrying twin ACCC (Aluminium Conductor Composite Core) "Hamburg" conductors and an OPGW earth wire.

The successful contractor will be responsible for the full detailed design and construction works associated with Vyrnwy Frankton tower line needs.

The total route length of the tower line for Vyrnwy Frankton is approximately 45km.

The intent is that the following long-time items will be procured by GGC and novated to the contractor:

• Tower steel work
• ACCC phase Conductor system

Design Works:

Full tower loading and strength assessment for the initial alignments produced by the FEED contractors, to include the detailed design of any tower strengthening requirements where necessary.

The design of all tower foundations.

Full electrical clearance assessment to include conductor profiling and tower wire clearance assessments, including production of route profiles and wire clearance diagrams.

Selection of insulators and fittings to Green Gen Cymru specifications, including production of component and string drawings.

Production of sag/tension book for conductor erection.

Construction Works:

Establishment of temporary working areas and accesses to include construction compounds, laydown areas, parking, welfare facilities, offsite road improvements, haul roads, drainages (pre and post construction as required) and soil management.

Procurement of all materials and components not free-issued by Green GEN Cymru (currently anticipated to be tower steelwork, ACCC phase conductor, and ACCC phase conductor fittings).

Installation of foundations, erection of towers, conductors, earth wire, insulators and fittings.

Design and construction of any required crossing protections e.g. scaffolds for road / rail crossings.

Provision of as-built records once construction complete.

Package 3 - Underground Cable

The Vyrnwy Frankton electrical network comprises 132kV and 33kV underground cable circuits and may require section of undergrounding in some of the overhead line circuits.

The successful contractor will be responsible for the full detailed design and construction works associated with Vyrnwy Frankton underground cable needs.

There are 3.5km of 132kV cable circuit (~180MVA capacity) and 3.5km of 33kV cable circuit (~50MVA capacity) associated with the Vyrnwy Frankton portfolio. Additional undergrounding section may be required through detailed design of the overhead circuits with different capacity requirements.

Design Works:

Full cable system design from the initial assessments produced by the FEED contractor.

The electrical design to include but not limited to:

• Load and short circuit studies
• Cable sizing and selection
• Earthing/bonding design
• The civil design to include but not limited to:
• Trench and duct design
• Joint bay/link box design
• Termination structures

Construction Works:

Establishment of temporary working areas and accesses to include construction compounds, laydown areas, parking, welfare facilities, offsite road improvements, haul roads, drainages (pre and post construction as required) and soil management.

Procurement of all materials and components.

Installation of ducted cable system including trenchless methods where necessary.

Design and construction of any crossing protections/methodologies.

Provision of as-built records once construction is complete.

Package 4 - Wood Pole

The wood pole lines for Vyrnwy Frankton network will be to the ENATS 43-50 "Trident" design and strung with either the "Upas" AAAC alloy conductor or "Oslo" ACCC high-temperature low sag conductor. An additional underslung fibre-optic cable will also be used.

The successful contractor will be responsible for the full detailed design and construction works associated with Vyrnwy Frankton wood pole requirements.

There are 3 wood pole circuits associated with Vyrnwy Frankton cover a total route length of approximately 100km.

Design Works:

Full pole and steelwork loading and strength assessment for the initial alignments produced by the FEED contractors, to include the detailed design of any strengthening requirements where necessary.

The design of all foundations.

Full electrical clearance assessment to include conductor profiling and wire clearance assessments, including production of route profiles and wire clearance diagrams.

Selection of insulators and fittings to Green GEN Cymru specifications, including production of component and string drawings.

Production of sag/tension book for conductor erection.

Construction Works:

Establishment of temporary working areas and accesses to include construction compounds, laydown areas, parking, welfare facilities, offsite road improvements, haul roads, drainages (pre and post construction as required) and soil management.

Procurement of all materials and components noting that in the case of Oslo ACCC the conductor and conductor fittings are anticipated to be free-issued by Green GEN Cymru.

Installation of foundations, erection of poles, conductors, fibre cable, insulators and fittings.

Design and construction of any required crossing protections e.g. scaffolds for road / rail crossings.

Provision of as-built records once construction complete.

1.4 Key Considerations - All Packages

All Equipment specified will be compliant with relevant national/international standards (e.g. IEC and BS EN) for a tower lines, wood pole lines, underground cable and substation environments.