Tender

Ask AI about this notice

Summarise, research or assess it with AI

View Markdown

Share this notice

Send this contract to a colleague

Site Power HV/LV Electrical Design

Sizewell C Limited

This public procurement record has 1 release in its history.

Tender

10 Aug 2026 at 14:10

Tender Notice
Summary of the contracting process

Sizewell C Limited is seeking electrical power systems design services for the Sizewell C construction site in the East of England. The work covers a robust and safe high-voltage and low-voltage distribution network for the Tunnel Launch Compound, temporary construction areas and ancillary construction areas supporting tunnel construction. The design must serve underground equipment including tunnel boring machines, slurry pumps, conveyors, ventilation, lighting and communications, as well as overground plant such as cooling water, compressed air, grout batching, dewatering and water treatment systems, cranes, site lighting, access control, welfare and offices. The scope also includes site lighting design. Electrical loading information will be supplied to the appointed design engineers.

The procurement has reached tender: the buyer invited suppliers to submit offers through a tender process. The requirement is for services covering electrical power systems design, with an estimated value between £50,000 and £100,000. The buyer set the submission deadline as 18 August 2026 at 16:32. The contract period is from 20 November 2026 to 12 February 2027. Deliverables include Stage 4 designs and schematics for the 11kV high-voltage network, substations, transformers, earthing, low-voltage distribution, feeder pillars, main distribution units, cable routes, containment and protective-device settings. Designs must be agreed with the wider Sizewell site team and comply with current British electrical safety legislation. The opportunity is identified as suitable for SMEs.

This opportunity suits electrical engineering consultancies and design practices experienced in temporary construction-site power infrastructure and complex HV/LV distribution. Strong capability is needed in 11kV network design, switchgear selection, cable sizing, cable routing and containment, protection settings and safe fault disconnection. Suppliers should be able to design substations, transformers and earthing systems for 690V and 400V supplies, and develop LV systems serving substantial construction plant and site facilities. The work also requires production of coordinated Stage 4 drawings, schematics and equipment specifications for lighting, substations, feeder pillars and distribution units. Experience integrating multiple plant loads across underground and overground construction compounds, and working with site teams to align designs with a wider electrical network, will be particularly relevant.

How relevant is this notice?

Notice Information

Notice Title

Site Power HV/LV Electrical Design

Notice Description

The HV/ LV electrical design is essential to develop a robust and safe electrical distribution network within the Tunnel Launch Compound (TLC), the STP, SXB, SMT areas within the Temporary Construction Area (TCA) and the Ancillary Construction Area (ACA) to support tunnel construction at the SZC site. The network will be required to distribute power to the following areas and equipment: Underground: Tunnel boring machines (TBMs), Slurry pump system Underground Conveyor belt system Ventilation system Lighting & Communication networks Ancillary tunnel construction equipment Overground: Ventilation system Cooling water system Overground conveyor belt system Overground slurry pump system Compressed air system Grout batching plant Dewatering system & water treatment plant Gantry cranes Site lighting, access control & communication systems Office building/ welfare Ancillary site activities Electrical loading details of the equipment listed above will be collated and provided by CWA to the selected electrical design engineers. The design will be required to comply with current British Electrical safety legislation. Key Deliverables: HV network design - Provide the design for the distribution of the 11kV network that feeds the TLC, TCA & ACA compounds complete with associated switchgear, cable sizing, cable routes and containment systems. Provide protection settings of circuit protective devices for safe disconnection of the supply under fault conditions. Stage 4 drawings complete with associated schematics to be provided of proposed cable routes, ducting sizing/ routes, substation locations. The design will need to be agreed with the CWA/ Sizewell site team to ensure power demands and circuit configurations are compatible with the wider HV network on site. Substation design - The design and specification of the substations complete with earthing design to distribute and transform where necessary the main 11kV supply that will be used to supply the above listed compounds. Where LV (690v/400v) supplies are required, suitably sized transformers to be specified to provide sufficient power for the supplied equipment. Stage 4 drawings complete with associated schematics to be provided of substations. LV Network - Provide the design for the distribution of LV network to supply required equipment/ plant with associated switchgear, cable sizing, cable routes and containment systems to required areas of distribution. Provide protection settings of circuit protective devices for safe disconnection of the supply under fault conditions. Stage 4 drawings complete with associated schematics to be provided of proposed cable routes, substation/feeder pillar locations, MDU sub main distribution locations. Site Lighting - Provide site lighting design to provide adequate lighting for site activities. Stage 4 drawings complete with associated schematics to be provided of lighting locations and specifications.

Notice Details

Publication & Lifecycle

Open Contracting ID
ocds-b5fd17-5642bf1a-b723-42dc-8746-99883c580954
Publication Source
Contracts Finder
Latest Notice
https://www.contractsfinder.service.gov.uk/Notice/8b23e699-4fcd-43eb-b901-a40d77868aeb
Current Stage
Tender
All Stages
Tender

Procurement Classification

Notice Type
Tender Notice
Procurement Type
Standard
Procurement Category
Services
Procurement Method
Not Specified
Procurement Method Details
Tender Suitability
SME
Awardee Scale
Not specified

Common Procurement Vocabulary (CPV)

CPV Divisions

65 - Public utilities

71 - Architectural, construction, engineering and inspection services

CPV Codes

65320000 - Operation of electrical installations

71314100 - Electrical services

71321000 - Engineering design services for mechanical and electrical installations for buildings

71323100 - Electrical power systems design services

71334000 - Mechanical and electrical engineering services

Notice Value(s)

Tender Value
£100,000 £100K-£500K
Lots Value
Not specified
Awards Value
Not specified
Contracts Value
Not specified

Notice Dates

Publication Date
10 Aug 20261 months ago
Submission Deadline
18 Aug 2026Expired
Future Notice Date
Not specified
Award Date
Not specified
Contract Period
20 Nov 2026 - 12 Feb 2027 1-6 months
Recurrence
Not specified

Notice Status

Tender Status
Active
Lots Status
Not Specified
Awards Status
Not Specified
Contracts Status
Not Specified

Buyer & Supplier

Contracting Authority (Buyer)

Main Buyer
Sizewell C Limited
Contact Name
Available with D3 Tenders Premium →
Contact Email
Available with D3 Tenders Premium →
Contact Phone
Available with D3 Tenders Premium →

Buyer Location

Locality
LONDON
Postcode
W1T 4EZ
Postcode Area
West London
Country
England
Major Region (ITL 1)
TLI London
Basic Region (ITL 2)
TLI3 Inner London - West
Small Region (ITL 3)
TLI36 Camden
Delivery Location
Not specified
Local Authority
Camden
Electoral Ward
Bloomsbury
Westminster Constituency
Holborn and St Pancras

Further Information

Notice Documents

Open Contracting Data Standard (OCDS)

View full OCDS Record for this contracting process

JSON Markdown

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.

Loading OCDS record...