If you want to connect to the transmission system, there are a number of charges you’ll need to pay – initially for your application, and then ongoing charges, all of which are collected by the Electricity System Operator ESO).
When you apply for a connection to the Electricity System Operator (ESO), there will be a charge for the application, depending on the size of your proposed scheme. The fees are set annually and published by the ESO.
Ongoing connection charges
Once your project is connected to the transmission system, you’ll need to pay ongoing charges that are collected by the ESO.
You can download the ESO's statement of charges which sets out the basis upon which charges will be made for the provision of our transmission services. These services include the planning, development, construction, maintenance and operation of new and modified connections to the transmission system.
A charge for new transmission assets or reinforcements specifically needed to connect your connection project to the electricity system.
This is charged by the Electricity System Operator to recover our costs for building and maintaining the assets which facilitate your connection project. A portion of this charge can be paid in full upfront or via an annualised charge (with the option of lump sum payments) over the life-time of the asset(s) we've built for you. One-off charges may be applied for any ‘non-standard’ works requested by you.
Transmission network use of system (TNUoS) charge
This charge recovers the cost of the Onshore Transmission Owners building and maintaining the national electricity transmission system, which all our customers benefit from using. The charge is based on your demand forecast and geographical tariffs are published annually. The Electricity System Operator also publishes quarterly forecasting information. See the Transmission Network Use of System (TNUoS) charges.
Balancing services use of system (BSUoS) charge
This covers the day-to-day costs the ESO incurs for balancing generation and demand on a minute-by-minute basis. BSUoS is calculated daily as a flat tariff for all network users.
The Electricity System Operator provides a forecast of BSUoS as part of the monthly balancing services summary report.
Both charges are billed monthly and will end if you terminate your contract with us. View the Balancing Services Use of System (BSUoS) charges.
You will need to lodge ‘securities’ with the ESO for your connection project whilst our connection works are ongoing. Securities provide commercial commitment for the investments we undertake to deliver your project, and are drawn down on in the event that you decide to cancel your connection project or reduce your capacity requirements after our work has begun. There are multiple routes to lodge securities depending on your organisation’s credit rating. The ESO can help you understand your options.
Where can I find more information?
You can learn more about financial securities in sections 2 and 15 of the Connection and Use of System Code (CUSC). There’s also a dedicated guidance document available for you to download that provides further information for generation projects.