Energy & Utilities Energy and utilities UK-wide

Grid Connection for Energy Projects

How to connect electricity generation projects to the UK grid. Understand the difference between DNO and National Grid routes, the G99 connection standard, and the April 2025 Ofgem reforms that promise £5 billion in savings and faster connection timelines.

Guide summary

Check your project’s size to choose the right grid connection route. For projects under 50MW, apply to your local Distribution Network Operator (DNO) under the G99 standard. For 50MW or more, apply to National Grid ESO. From April 2025, new reforms speed up connections and cut costs, but you must meet milestones to keep your place in the queue.

  • Check project size: under 50MW = DNO, 50MW+ = National Grid
  • Apply for a connection agreement before exporting power
  • Follow G99 standard for distribution connections under 50MW
  • Expect wait times up to 15 years for large projects
  • Prepare for connection costs of millions for 20MW+ projects
  • Keep planning permission ready to benefit from 2025 reforms
  • After offer accepted, work with network operator on design and tests
  • For transmission connections, sign a CUSC agreement
  • Reforms prioritise shovel-ready projects – meet milestones or lose place
  • Reforms aim to save £5 billion and clear the queue
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Connecting to the electricity grid is a critical milestone for any electricity generation project. Whether you're developing a wind farm, solar array, or hydrogen production facility with electrolysis, you cannot export power without a grid connection agreement.

The path you take depends on your project's capacity: smaller projects (typically under 50 MW) connect via your local Distribution Network Operator (DNO), while larger projects connect to the transmission network via National Grid ESO.

Grid connection reforms (2025)

In April 2025, Ofgem approved major reforms to the electricity connections process. The 'First Ready, First Connected' (TM04+) process came into force in January 2025 for new transmission connection applications, with reforms expected to deliver significant savings across the industry and significantly reduce connection wait times.

Key changes include:

  • Queue management: Projects that fail to meet milestones (planning submission, land agreements) will be removed from the queue, freeing capacity for shovel-ready projects
  • Prioritisation: Projects with planning consent or environmental permits receive accelerated connection timelines
  • Strategic network planning: Network operators must publish long-term capacity plans to guide project siting decisions
  • 'First Ready, First Connected': Transmission applications follow a two-gate process (TM04+) where Gate 2 offers require proof of planning progress

These reforms are designed to clear the 700GW+ connection queue - over four times the installed capacity needed by 2050 - and accelerate the transition to clean energy.

What happens after securing a connection agreement

Once you've accepted a connection offer and paid your deposit, you'll work with the network operator to design the connection infrastructure, agree protection settings, and schedule commissioning tests.

For transmission connections, you must also execute a Connection and Use of System Code (CUSC) agreement, which governs ongoing use of the transmission network and includes charges for system operation.

Allow several months between securing your connection agreement and energisation for design work, construction of grid infrastructure, and compliance with Grid Code or Distribution Code technical requirements.