Applying for an electricity connection
On this page you will find details about qualifying to connect to the national electricity transmission system (NETS) and what you need to in order to make an application to connect.
The processes of connecting to and operating electricity generators in Britain vary between England/Wales and Scotland. National Grid owns and operates the NETS in England and Wales and operates the system in Scotland. The ownership of the transmission system in Scotland is shared between two companies or transmission owners (TOs): Scottish Hydro Electricity Transmission PLC (SHE Transmission) and Scottish Power Transmission (SPT).
There are differences between Scotland and England/Wales. For example, customer assets will be physically connected to National Grid owned assets in England and Wales; in Scotland, the customer assets will be connected to the transmission assets owned by one of the Scottish TO companies. Connections to the NETS in England and Wales tend to be larger than those in Scotland. Generators are required to be at least 100MW to be connected to the transmission system in England and Wales, which is different to Scotland, where smaller generation is connected.
For embedded generators, when you embark on a new connection project, one of the first things you need to be aware of is the current availability of capacity on the DNO’s network. For England and Wales projects this HeatMap will provide you with an overview of the existing capacity.
Applying for a connection
In these sections, you will find the steps you need to take to apply for either a direct connection or embedded generation.
Transmission connected generation
In order to apply for a direct connection to the transmission system you will be required to complete all of the following:
Transmission connected demand
Demand customers applying directly to connect to the transmission system will be required to:
Interconnectors applying to connect to the transmission system will be required to:
complete a connection application form (CUSC Exhibit B - Directly Connected Power Station);
The Interim Interconnector Connection Process document sets out the principles and proposals for the interim process of managing requests to connect interconnectors to the NETS.
The Interconnector User Guidance document sets out the agreements to sign and the process to follow for those customers who use interconnectors.
Smaller commercial and domestic connections are generally qualified as under 10 MW in Scotland and under 150MW in England and Wales. It would be unlikely for these types of customers to require an agreement with National Grid, due to the size of the project or connection. In the first instance, you should contact your local distribution company.
Small embedded generation
Small generators wishing to connect to the distribution network, that do not require explicit access rights to the NETS, will make all agreements with the DNO. However, if the DNO believes the proposed small power station may have an impact on the NETS, they may contact us.
Following this, we will assess whether there is a need to reinforce the transmission network as a result of the new distribution connection, and this is called a statement of works (SOW). The Small Embedded Generation and National Grid guidance document provides small generators and other interested parties with an understanding of National Grid’s involvement in distribution connections, and what a new generator can expect from the SOW process.
Large embedded generation
Large generation customers who are applying to connect to the distribution network are also required to have a connection offer with National Grid. Large generators are categorised as the following:
100 MW or greater in National Grid’s transmission network;
30 MW or greater in Scottish Power’s transmission network; and
10 MW or greater in Scottish Hydro Electric’s transmission network.
The two options for this type of customer are Bilateral Embedded Generation Agreement (BEGA) and Bilateral Embedded Licence Exemptible Large Power Station Agreement (BELLA).
The BEGA states how generators will be required to comply with the:
The BEGA will also provide the customer with transmission entry capacity (TEC) as the customer will have the right to operate in the electricity balancing market and export onto the NETS.
To apply, BEGA customers will be required to:
complete a connection application form (CUSC Exhibit D – BEGA Generator);
The BELLA states how generators will be required to comply with the:
Grid Code; and
Connection and use of system (CUSC).
The user does not have to adhere to the Balancing and Settlement Code (BSC) because a BELLA does not automatically give the customer rights to operate in the electricity balancing market and export onto the NETS. However, it is possible for a BELLA user to actively participate in the balancing mechanism without TEC, provided the user installs the necessary hardware (EDL, EDT and control telephony). To do this, a user must request to vary the BELLA to include the relevant technical appendices. Once this is complete, the normal compliance process is followed to make sure that the relevant equipment has been installed.
To apply, BELLA customers will be required to:
Understanding the application process
To understand the costs associated with connecting to the NETS, please refer to the Charge Modeller and Application Fee Calculator document. The Charge Modeller provides an indicative cost for the annual connection charge for new assets being installed and allows you to create hypothetical scenarios based on various factors. The Application Fee Calculator calculates the cost of an application fee based on the location of the connection, size of connection and offer type.
This provides a consistent methodology for Generation Customers to provide financial security for the transmission reinforcement works their connection triggers and has been codified in Section 15 of the Connection and use of System Code (CUSC) as a result of CUSC Modification Proposal 192, 219, 222 & 223.
These documents will help you better understand the securities process:
These arrangements replace the Final Sums methodology and the Interim Generic User Commitment Methodology for Generation and Interconnector Customers. The Final Sums methodology continues to apply for the Demand Customers.
Interactive Offer Policy applies where an offer for connection to a customer is due to be made but it would affect the terms of another open offer reliant upon the same transmission reinforcement works.
We have published guidance for managing interactive offers which will explain the process we follow to allocate capacity in these circumstances:
Connection and Use of System Code
The Connection and Use of System Code (CUSC) is the contractual framework for connection to, and use of, the National Electricity Transmission System.