Planning

Vyrnwy Frankton IEOI PQQ

GREEN GENERATION ENERGY NETWORKS CYMRU LIMITED

This public procurement record has 1 release in its history.

Planning

15 Dec 2025 at 11:36

UK2 - Preliminary Market Engagement Notice
Summary of the contracting process

The public procurement process initiated by Green Generation Energy Networks Cymru Limited involves an Invitation for Expressions of Interest (IEOI) for the Vyrnwy Frankton Project. This process is in the planning stage and adheres to Welsh devolved regulations. The procurement relates to the energy sector, focusing on electricity distribution and related services within the UKL (Wales) region. The IEOI involves packages for the design, installation, and construction of substations, tower lines, underground cables, and wood pole lines. Key dates include a response deadline for the IEOI and Pre-Qualification Questionnaire (PQQ) by 25th January 2026, with shortlisted tenders progressing to a contract period slated from October 2026 to October 2029.

This tender provides substantial opportunities for businesses specialising in high-voltage electrical infrastructure, civil engineering, and construction. Companies with capabilities in designing and implementing complex electricity networks, particularly those with experience in 132kV systems, will find this project highly suitable. Engaging with this tender could offer growth potential for firms in providing comprehensive energy solutions, facilitating expansion into the Welsh market through significant infrastructure projects supported by strategic collaboration with established institutions like Stantec during the FEED contract phase. Businesses in the electrical distribution and construction sectors can leverage this tender to expand their portfolio with large-scale public utility projects.

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Notice Information

Notice Title

Vyrnwy Frankton IEOI PQQ

Notice Description

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.

Planning Information

Scope of engagement is via a Invitation for Expressions of Interest (IEOI) and Pre-Qualification Questionnaire (PQQ). IEOI and PQQ response closing date is the 25th January 2026. Interested parties must complete an return an Non-disclosure Agreement before the IEOI/PQQ can be provided. Request for NDA should be submitted to - supplychain@greengencymru.com The EOI Process represents the first stage in the selection of the Preferred Tenderer and is primarily focused on company / organisational capability. A number of mandatory requirements are outlined as Mandatory Criteria' Respondents will be assessed on these on a pass / fail basis. EOI Responses will be assessed against the Evaluation Criteria outlined in Section 3.5 to select a short-list of Respondents who will be invited to participate in the ITT Stage. Respondents may be given the opportunity, at Green Gen Cymru's discretion, to give a presentation to the Evaluation Panel and advisers on their EOI Response. Green GEN Cymru present intention is to short-list a number of Respondents such that there are three, up to a maximum of four, Tenderers for each package. This number may be varied at Green GEN Cymru's sole discretion. The short-list will be informed by the responses to this EOI. Respondents will only be eligible for short-listing if they have submitted a sufficiently comprehensive EOI Response, including all of the information listed in the Documentation Checklist in Appendix A of this IEOI / PQQ.

Notice Details

Publication & Lifecycle

Open Contracting ID
ocds-h6vhtk-05f589
Publication Source
Find A Tender Service
Latest Notice
https://www.find-tender.service.gov.uk/Notice/082823-2025
Current Stage
Planning
All Stages
Planning

Procurement Classification

Notice Type
UK2 - Preliminary Market Engagement Notice
Procurement Type
Standard
Procurement Category
Works
Procurement Method
Not Specified
Procurement Method Details
Not specified
Tender Suitability
Not specified
Awardee Scale
Not specified

Common Procurement Vocabulary (CPV)

CPV Divisions

31 - Electrical machinery, apparatus, equipment and consumables; lighting

44 - Construction structures and materials; auxiliary products to construction (except electric apparatus)

45 - Construction work

65 - Public utilities

CPV Codes

31321000 - Electricity power lines

31682540 - Substation equipment

44212200 - Towers, lattice masts, derricks and pylons

44212220 - Pylons, poles and pickets

44212221 - Pylons

44212224 - Poles for carrying overhead lines

45220000 - Engineering works and construction works

65300000 - Electricity distribution and related services

Notice Value(s)

Tender Value
Not specified
Lots Value
Not specified
Awards Value
Not specified
Contracts Value
Not specified

Notice Dates

Publication Date
15 Dec 20252 months ago
Submission Deadline
Not specified
Future Notice Date
15 Apr 20262 months to go
Award Date
Not specified
Contract Period
8 Oct 2026 - 9 Oct 2029 3-4 years
Recurrence
Not specified

Notice Status

Tender Status
Planning
Lots Status
Planning
Awards Status
Not Specified
Contracts Status
Not Specified

Buyer & Supplier

Contracting Authority (Buyer)

Main Buyer
GREEN GENERATION ENERGY NETWORKS CYMRU LIMITED
Contact Name
Not specified
Contact Email
supplychain@greengencymru.com
Contact Phone
Not specified

Buyer Location

Locality
CARDIFF
Postcode
CF10 1DY
Post Town
Cardiff
Country
Wales
Major Region (ITL 1)
TLL Wales
Basic Region (ITL 2)
TLL5 South East Wales
Small Region (ITL 3)
TLL52 Cardiff and Vale of Glamorgan
Delivery Location
TLL Wales
Local Authority
Cardiff
Electoral Ward
Cathays
Westminster Constituency
Cardiff South and Penarth

Further Information

Notice Documents

Open Contracting Data Standard (OCDS)

View full OCDS Record for this contracting process

Download

The Open Contracting Data Standard (OCDS) is a framework designed to increase transparency and access to public procurement data in the public sector. It is widely used by governments and organisations worldwide to report on procurement processes and contracts. 

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        "description": "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. 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