Stansted North Site

Power On is delivering the extra high-voltage and high-voltage electrical infrastructure for Stansted North Site – a landmark 170-acre commercial development located to the north of Stansted Airport’s runway.

Appointed by Threadneedle Columbia Ltd, Power On is providing a new 33kV grid connection from the grid point at Bishop’s Stortford substation, together with the design and construction of a new 33/11kV primary substation to power the scheme. The project is led by Major Infrastructure Project Manager Paul Hammond, supported by Senior Design Engineer Eva Raikidou and Site Supervisor Danny Shiner.

The development will deliver multiple commercial units ranging from 30,000 sq ft to 1,000,000 sq ft, creating a strategic hub for e-commerce, life sciences, technology and logistics businesses in a prime South East location.

The masterplan is underpinned by a long-term energy strategy focused on reducing carbon impact through efficient energy usage, sustainable material choices and integration of low carbon technologies. The primary substation infrastructure has been designed to support this strategy and enable phased expansion as the site evolves.

What Power On Delivered

Power On acted as Principal Designer and Principal Contractor, delivering a fully integrated, end-to-end infrastructure solution – from feasibility and point of connection through to construction, energisation and long-term operation.

Scope of works included:

• Liaising directly with the DNO and managing the 33kV point of connection from appointment through to energisation
• Installation of an approximately 8km 33kV off-site cable route
• Installation of two 40MVA 33/11kV EHV circuits and two signal pilot cables
• Construction of a new 33/11kV primary substation
• Installation of two 33/11kV transformers
• Construction of a new site entrance (S278) and on-site access road
• Adoption and lifetime operation of the primary substation
• The scheme involved the installation of over 64km of 33kV cable.

The dual 33kV circuit supply to two 40MVA 33/11kV transformers, with the project included the full design and construction of the Primary Substation buildings and compound for adoption by Power On’s IDNO ENC. This Primary infrastructure will provide up to 35MVA capacity for the future phased site wide development.

Engineering and Stakeholder Challenges

Delivering infrastructure at this scale required extensive coordination across statutory bodies, third-party landowners and airport stakeholders.

Complex off-site route

The circa 8km cable route presented multiple engineering challenges and required third-party approvals, including three watercourse crossings (Environment Agency), a railway bridge crossing (Network Rail and local authority approval) and a motorway crossing beneath the M11 (National Highways approval).

Power On engaged early with each stakeholder to agree engineering methodologies and approval pathways, reducing programme risk and securing the necessary consents prior to construction.

Directional drilling was used across the majority of crossings to minimise surface disruption and environmental impact. For the railway bridge crossing, a bespoke cable protection system was designed and installed over the bridge deck to meet the technical requirements of both Network Rail and the local authority structures team.

Bespoke cable installations with enhanced mechanical protection were also completed across two culverts along the route to ensure long-term resilience.

Power On negotiated directly with third-party landowners to secure easements for the cable route and obtained the required consents for sections of unregistered land, preventing potential delays to the delivery programme.

On-site constraints

The primary substation was constructed on airport-owned land, requiring strict compliance with Stansted Airport’s permit-to-work procedures before any ground-breaking activities could begin. Additional security measures – including static guards and monitored tower cameras – were implemented due to the sensitive location.

The 170-acre site features significant level changes. Detailed cut and fill modelling was undertaken to determine appropriate formation levels for the substation. Flood susceptibility identified through the Flood Risk Assessment (FRA) led to a specialist drainage study to mitigate risk and ensure compliance.

Power On also supported the client in discharging planning conditions, including completion of a formal noise impact assessment.

The site is environmentally sensitive and regarded as a haven for wildlife, requiring full compliance with environmental legislation throughout the works.

Why Power On

Power On was selected following a detailed feasibility phase, during which the team identified technical risks, approval requirements and delivery constraints at an early stage.

This thorough upfront approach enabled Power On to present a risk-managed solution with a firm contract price, providing commercial certainty for a large-scale, phased commercial development.

The versatile nature of the Stansted North Site masterplan required infrastructure capable of adapting to evolving occupier requirements. Power On has worked closely with the client throughout the project lifecycle to ensure electrical capacity, delivery programme and long-term operational strategy align with the site’s changing needs.

By combining grid connection expertise, third-party approvals management, primary substation construction and lifetime adoption within a single integrated delivery model, Power On provides both immediate technical capability and long-term strategic value.