NESO has sought to overhaul the energy procurement process given the increased demand for power, a result of the growing digital economy and its essential infrastructure: data centres. The NESO demand application window closed in March 2025, pausing project submissions until at least Q4 2025. Consequently, extra high voltage power projects (>132kV in England & Wales, >33kV in Scotland) face a 6–9-month delay before being considered.

According to the International Energy Agency (IEA), the estimated global data centre electricity consumption in 2022 was 240-340 TWh, or around 1-1.3% of global final electricity demand. In the European Union (EU), data centre energy usage amounts to approximately 40-45 TWh, equivalent to 1.4-1.6% of total EU electricity consumption. By 2030, data centres are forecast to account for 3.2% of electricity demand within the EU, up 18.5% from 2018.

This closed period is crucial for data centre operators preparing to submit new project plans. Strategic planning and proactive measures are essential to ensure readiness when applications reopen.

A new system

The transmission connection process for large scale demand, particularly hyperscale projects, is shifting from a first come, first served model to a first ready, first connected system. This requires more thought from developers and operators, demanding detailed design plans and land agreements to secure a firm, definitive offer. 

Global hyperscale data centre capacity will double in the next four years according to Synergy Research, with around 125new facilities launching each year. These huge deployments have requirements ranging from 10 acres to hundreds of acres and power capacity from 100MVA to a gigawatt. NESO’s increased authority to adjust connection dates based on project progress adds another layer of complexity.

Strategic planning

To navigate these changes, data centre operators must prioritise comprehensive planning and coordination. Ensuring that all design details are meticulously prepared and land agreements are in place will be crucial. The ability to meet milestones agreed upon with National Grid will significantly impact connection dates and could determine whether a project remains in the queue or is removed entirely.

Distribution level projects

While projects at the distribution level can continue to apply and progress, they may face challenges in obtaining definitive answers from NESO and transmission operators through the statement of works process. This uncertainty highlights the importance of thorough preparation and strategic planning.

Existing connections

These reforms are however good news for data centre projects that already hold a connection, which have become very valuable. 

New projects exceeding 150MW in England are unlikely to receive firm power offers for approximately a year. Meanwhile, most Scottish projects will be unable to apply at the distribution level, likely affecting all new data centre developments. Therefore, maintaining and leveraging existing connections is essential for continued growth and stability.

What’s next?

Large energy consumers must act now to prepare for the next NESO demand window. This involves:

1. Detailed planning: Ensuring all design details are finalised and land agreements are secured before the window opens.
2. Coordination: Collaborating with stakeholders to meet milestones and avoid delays.
3. Strategic positioning: Leveraging existing grid connections and planning for future applications to maintain growth and stability.

By taking these proactive steps, energy hungry consumers can navigate the upcoming changes and position themselves for success when the window reopens in Q4 2025. 

The time to act is now, ensuring readiness and resilience in the face of evolving energy landscape.

Further information

Contact Luisa Mostarda or Cameron Bell

Private wire: Boosting energy project value for landowners, developers and occupiers