The voice of the networks

Connecting to the networks

We help maintain the safety and operation of the energy networks though ensuring connections are compliant with the UK and GB technical and legal requirements.

Electricity engineer climbing electrical pole
ENWL

Electricity Networks

  • Distributed generation

    Generating electricity from renewable and energy-efficient sources is a key part of the government’s strategy to tackle climate change. We believe that the introduction of the correct commercial and regulatory framework is the single most important factor in how network operators can support the government’s target for renewable and energy-efficient generation.

    Many industry-specific terms and definitions are used by network companies and their stakeholders in describing aspects of connections. The full definitions for many defined terms are provided in industry code documentation. As part of the Open Networks project, a “Plain English” Terms and Definitions document and a guide on the connection application process have been published collating and explaining many of the more frequently used terms and explaining what is required and the process when applying for a generator connection.

  • Compliance and requirements for generators

    In April 2016 EU Commission published 2016/631 The EU Network Code “Requirements for Generators” (RfG) which was incorporated into UK law and led to the development of ENA documents:

    • EREC G98 “Requirements for the connection of Fully Type Tested Micro-generators (up to and including 16 A per phase) in parallel with public Low Voltage Distribution Networks on or after 27 April 2019”
    • EREC G99 “Requirements for the connection of generation equipment in parallel with public distribution networks on or after 27 April 2019”

    While other factors will influence which requirements a connection application should be made, fundamentally if the connection application is for a generator export of less than 3.68kW/phase then EREC G98 applies, connection applications for greater than 3.68kW/phase then EREC G99 applies.

    Both connection applications have a set of application forms to use, which have been bundled into zip folders to download. You can find G98 forms zip folder, G99 forms zip folder and all other related forms and guidance documents in our Resource library when you search 'G98' or 'G99'.

    Both EREC G98 and EREC G99 contribute to supporting the network operator in meeting their Licence obligations and Generators must be able to demonstrate compliance with the requirements before a connection is commissioned.

    Compliance is the responsibility of the customer who is quite often, but not always, the owner of the generation. Owners are required to make sure that generation equipment they purchase and install complies with the law.

  • Ensure distributed generation equipment is compliant

    In order to help determine what equipment is compliant, we provide a repository, the ENA Type Test Register, where equipment manufacturers can submit information about their products and make their own declarations of compliance to G98 or G99. The ENA Type Test Register enables all visitors to access the type test verification for products related to small scale electricity generation in the UK market up to 50kW.

    We review the information submitted and where the information is found to be correct and complete the entry will be marked “Accepted”, all other submissions whether they are yet to be reviewed or have not yet provided all of the necessary correct information are considered “Pending”.

    The onus is on manufacturers to produce equipment that is compliant with the legal requirements, and upon request (from owners, installers, developers, and DNOs) be able to demonstrate this with appropriate evidence. We urge manufacturers to ensure that their generation equipment is demonstrably compliant as it is in the interests of all their customers, from the supply chain to final owners.

    G98, which applies to domestic scale generation equipment rated at 16 amperes or less, requires that manufacturers must lodge their declarations of compliance in the ENA Type Test Register. This is not mandatory to make a submission under G99 for any generation equipment larger than 16 amperes but is still recommended.

  • Distributed generation connection guides

    In order to help support an application through the process we have produced the Distributed Generation Connection Guides, each with a corresponding ‘Summary’ guide. The purpose of the summary guides is to act as a quick check, providing only the most useful information in a condensed format.

    Each ‘full’ guide has a flowchart that guides you to the most relevant connection guide for the distributed generation you are planning to install. The guides are intended to help you, as an owner or developer of distributed generation, to connect your generating plant to one of the UK’s electricity distribution networks.

    These can be found in our Resource library.

  • Application, compliance and decommissioning forms

    In order to support the development of distributed and facilitate consistency in the connection application and assessment process we have produced forms which are available in our Resource library.

    We don’t process these forms so please send your completed forms to the local network operator in the area where your generation is to be connected.

  • Fast-track application process for integrated microgeneration and storage

    The electricity industry is experiencing a significant upturn in low voltage connection applications for small scale generation and energy storage schemes. Network operators, in conjunction with the government and Ofgem, have considered that some application and testing requirements can be a barrier in terms of application timescales for small scale domestic micro-generation and storage schemes.

    The fast track integrated microgeneration and storage procedure can be followed where all the following conditions apply:

    1. The power generating modules are in a single installation.
    2. The total aggregate capacity of the power generating modules (including electricity storage devices) is between 16 A and 32 A per phase.
    3. The total aggregate capacity of the power generating modules that are electricity storage devices does not exceed 16 A per phase and the total aggregate capacity of the power generating modules that are non-electricity storage devices does not exceed 16 A per phase. If the total aggregated capacity of Electricity Storage and non-Electricity Storage devices is no greater than 16 A per phase, the single premises procedure described in EREC G98 applies.
    4. All of the power generating modules (including electricity storage devices) are connected via EREC G98 fully type tested inverters.
    5. An EREC G100 compliant export limitation scheme is present that limits the export from the Generator’s Installation to the Distribution Network to 16 A per phase. Engineering Recommendation G100 (2018) – Technical Guidance for Customer Export Limiting Schemes provides guidance on the connection of customer export limiting schemes (ELS) that operate in parallel with the Distribution Systems of licensed Distribution Network Operators (DNOs). You can find EREC G100 and its supporting EREC G100 appendices in our Resource library.
    6. The power generating modules will not operate when there is a loss of mains situation.
  • Fast-track application terms and conditions

    Only if all the conditions are satisfied should the generation owner complete an application in a format as shown in G99 Form A1-2.

    The planned commissioning date stated on the application form shall be between 10 working days and three months from the date that the application is submitted to the DNO. Confirmation of the commissioning of each power generating module shall be made no later than 28 days after commissioning (where commissioning tests and checks are not witnessed).

    Confirmation shall be provided in a format as shown in G99 Form A3-2.

    In addition, an EREC G100 Export Limitation Scheme Installation and Commissioning Tests form shall be submitted to the DNO to confirm that the export limitation scheme meets the requirements set out in EREC G100. Confirmation shall be provided in a format as shown in ENA EREC G100 Appendix B.

    You can find all EREC G99 and G100 documents in our Resource library.

Connecting electric vehicles and heat pumps

You may need to contact your network operator before the installation of a low carbon technology can take place.

  • When to contact your network operator

    There are numerous reasons why network operators may need to be contacted before the installation of a low carbon technology can take place.

    These include supply overload, damage to supply equipment, power quality issues or adequacy of earthing. If these issues are identified but not reported prior to installation, consumers can be at risk.

    Even when the cut-out rating is known by the installer, the ratings and utilisation of all local distribution network assets require consideration, and cannot be ascertained without contacting the network operator in that area.

    When we do not receive notification of low carbon technology installations, we are unable to map the increased network load associated with the rollout of these technologies. This leads to incomplete modelling, which can in turn cause inadvertent stress on assets and ineffective and uneconomic asset replacement programmes – the cost of these programmes is passed onto UK consumers.

  • Keeping everyone safe

    Everyone involved in the deployment of low carbon technologies has an obligation to ensure they do their utmost to keep our customers safe.

    Installers have the responsibility to inform network operators when making modifications to a service under the following:

    • Wiring Regulations BS7671 132.16 Additions and alterations
    • Distribution Code DPC5.2.1
    • IET Electric Vehicle Code of Practice

    Note that the requirements under the Wiring Regulations and the Distribution Code are technology/appliance agnostic and apply to supply alterations from the installation of any appliance.

    The Department for Business, Energy & Industrial Strategy (BEIS) has a responsibility to ensure that Low Carbon Technology installers are informing us of installations made under its subsidies – the Renewable Heat Incentives and the Electric Vehicle Homecharge Scheme, etc.

  • Process for heat pump and EV charging infrastructure installations

    Electric vehicle and heat pump connection forms and processes share the same documentation. We have created a Combined Installation Process flowchart (also available in our Resource library) illustrating the connection process which must be followed when installing an electric vehicle or heat pump.

    • Electricity network operators will never refuse a connection but work may be required to ensure the connection is fit for purpose
    • For residential properties with new Maximum Demand (MD) between 60A and 100A inclusive – the installer must apply for a connection prior to installation by filling in the form mentioned below and the network operator will assess the supply capacity within 10 working days
    • For commercial properties, you should follow the Combined Installation Process Flow Chart
  • Application forms

    An associated application form (also available in our Resource library) for heat pumps and electric vehicles, which must be completed and sent to the network operator, has been created. This should allow consistency of application to network operators across Low Carbon Technologies. The form is the same whether the installation is a ‘Connect & Notify’ or an ‘Apply to Connect’.

    For applications that consist of multiple installations, whether at the same premises or multiple premises, a relevant multi-installation spreadsheet (available too in our Resource library) has been created.

    The process is maintained and governed by our Low Carbon Technologies Working Group. This group contains representatives of all UK transmission and distribution electricity networks, and meets regularly with industry, BEIS, the Office for Low Emission Vehicles (OLEV) and Ofgem (the UK energy regulator) to discuss issues and agree strategies and processes for Low Carbon Technologies that connect to the electricity networks.

  • Submitting your form

    Submit the completed connections form to your local network operator through the corresponding operator email address for EV notifications.

    If remedial work is required by the network operator, the time taken to carry out this work will vary depending on the nature of the intervention required to deliver an adequate supply to the premises being assessed. Each connection is different, so the premises and network must be assessed before providing an estimated time of delivery.

    Under all circumstances there is a requirement to inform the network operator of the installation. For help identifying the correct electricity networks for your premises please use our Who's my network operator? tool to check who is your operator. You can also find your network operator using the Meter Point Administration Number (MPAN). Digits 9 and 10 of the 21-digit Meter Point Administration Number (MPAN) are the Distributor ID. You can refer to the reference document for operator email addresses that lists which network operator corresponds with each Distributor ID.

  • Installations in excess of 20MW

    For installations in excess of 20MW, you may also want to consider a connection to the Transmission System. In this case please contact National Grid Transmission Owner in England & Wales, SSEN Transmission in the north of Scotland and SPEN Transmission in the south of Scotland.

  • Heat pump database

    This is available on our Databases page.

Gas networks

Distributed gas entry is becoming ever more commonplace in the gas network. The technical requirements to connect these onshore and typically small scale sites differ from network to network company and as such a programme of standardisation has been ongoing since 2018.

  • Distributed gas connection standardisation

    Distributed gas entry is becoming ever more commonplace in the gas network. The technical requirements to connect these onshore and typically small scale sites differ from network to network company and as such a programme of standardisation has been ongoing since 2018.

  • Site acceptance testing

    We have developed and agreed with its gas network members a list of required Site Acceptance Tests to allow biomethane sites to demonstrate their compliance to FWACV and GS(M)R regulation. Currently, different approaches are being employed and there’s a lack of consistency in respect of the testing being undertaken and the evidence produced.

    To address this, methodologies are proposed to be supplied by individual service providers which meet the requirements. These methodologies can then be agreed by the GDNs to be used for all future testing.

    This will allow more efficient and effective methods of undertaking, recording and approving the testing of the GEU gas quality and measurement systems allowing DFOs and GDNs to satisfy regulatory obligations.

    GEU suppliers are reviewing their methodology to satisfy these requirements. If you have any questions regarding the specific requirements and tests please contact the gas team.

  • Commissioning RHI tariff guarantee biomethane plant

    Following the passing into law of the reforms to the Renewable Heat Incentive (RHI), over thirty biomethane plant successfully applied for a Tariff Guarantee as a route to commissioning under the RHI.

    To support the commissioning of these plant we set out our view on the usual standards and practices for commissioning in an open letter.

    Towards the end of 2019 Ofgem ran a call for evidence on industry standards and practices for commissioning equipment used in the production of biomethane to which we responded, setting out the following:

    Industry standards and practices for commissioning

    Our view of the industry standards and practices as is determined by IGEM GL5 Edition 3 – Managing New Works, Modifications or Repairs to any plant or system associated with the supply of fuel gas, and by IGEM/TD/16 Edition 2 which ensures that a network commissioning team is “properly trained, assessed as competent and certified as such by a recognised industry body”.

    Implementation of the IGEM GL5 Edition 3 standard ensures compliance with all applicable health and safety legislation pursuant to biomethane plant commissioning, notably the Dangerous Substances and Explosive Atmospheres Regulations, Electricity at Work Regulations, Gas Safety (Management) Regulations, Pipeline Safety Regulations and the Pressure Systems Safety Regulations. Adherence to these regulations will be common for all biomethane plant or the Delivery Facility Operator (DFO) that is commissioned.

    Although the gas networks have their own versions of IGEM GL5 (PS6/G17) to account for different approaches to Remote Operable Valve (ROV), telemetry, odorisation processes etc., IGEM GL5 is the recognised industry standard to which all network-specific forms and certification that is completed must comply.

    Accordingly, it is the agreed view of the gas networks that the two forms and process set out below reflect the “usual industry standards and practices for commissioning” as per the RHI legislation.

    1. IGEM GL5 Edition 3
    a) For all assets upstream of the ROV Part D will need to be completed and signed off by a competent commissioning engineer.
    b) Gas networks will need to complete and have signed off by a competent commissioning engineer their sections, usually those relating to telemetry & ROV certification.

    2. Safe Control of Operations – i.e. Non-Routine Procedure (SCO4)
    a) For DFO assets documentation is required to be completed and signed off showing capability of serviceable DFO assets to network ROV. This function demonstrates capability of operating and passing gas into the GDN system.
    b) Network SCO4 documentation shall be completed and approved in preparedness for the commissioning of network assets (i.e. ROV) to support gas flows into the system.
    While the developers of a biomethane plant or DFO will have their own set of responsibilities, standards and practices we believe the above industry standards and practices are correct for commissioning biomethane plant and that continuing to follow this approach is appropriate to ensure networks conform to their legal responsibilities.

FAQs about connecting to the networks

  • When do I need to contact the network operator prior to installing a charge point or heat pump?

    This is clearly defined in our connection process. Network operators have agreed that customers/installers must contact the appropriate network operator directly in a range of instances including the following:

    • The MD calculations performed by the installer indicate that a property’s MD is greater than the known supply capacity
    • There are safety concerns over the cut-out, cut-out fuse, or any other existing equipment
    • There is uncertainty over the supply capacity or the adequacy of the supply
    • It is certain that the connection requires an upgrade
    • There is a looped supply
    • It is an unmetered supply

    The network operator will then assess the records of the property and confirm if the supply to the property is adequate, or raise a job to assess the property directly and implement any interventions where necessary.

    This means that in addition to the ‘Connect & Notify’ requirement, if the new load will exceed the existing supply, or if there is a planned programme of installations in a close geographic region, the network operator should be contacted well in advance of the installation.

    The purpose of this process is to allow a safety assessment of the electrical supply to the domestic property and the supporting network to ensure they are adequate.

    Once the installer contacts the network operator, the information required to enable the network operator to carry out the assessment will need to be provided, as per the application form.

    All forms can be found in the "Connecting electric vehicles and heat pumps" section above and supporting guidance can be found in our Resource library.

  • Do all installations to existing properties require network operator intervention?

    No, installations where the Maximum Demand of the premises including the new load is ≤60A per phase and adequacy of the connection is known, the network operator must be notified post-installation (within 28 days). This assumes that there are no safety concerns, as per the process.

  • When do I need to make an application?

    Every time an installer or customer installs an Electric Vehicle charge point or Heat Pump to an existing property, they must inform their network operator accordingly.

    This will be in the form of an application or a notification. Notification is the process whereby if the proposed addition/alteration is assessed by the installer to be within the existing rating of the supply equipment and the MD is ≤60A, then the EV charge point or Heat Pump can be installed and the network operator will be notified retrospectively (within 28 days).

  • How do I submit an application/notification form?

    Compete the single notification form or the multi-notification spreadsheet and submit directly to the network operator. Both forms and network operator contact details can also be found in our Resource library.

  • Who can submit an application?

    Anyone who is competent to install an electric vehicle charge point or heat pump can submit a form, including instances where the installer is working on behalf of the customer at that property. Ultimately, it is the responsibility of the connecting customer to ensure that the correct data is submitted.

  • Will network operators refuse the installation of an electric vehicle charge point or heat pump?

    No, network operators are obliged to facilitate the installation/connection of new loads to the power network, as part of their license condition.

  • How long will it take for remedial works to be completed?

    This will vary depending on the nature of the intervention required to deliver an adequate supply to the property being assessed. Each connection is different, so the premises and network must be assessed before providing an estimated time of delivery.

  • What is Maximum Demand (MD)?

    The Maximum Demand of a circuit, property, section of network, or network that considers that all loads associated with that network will not be drawn at the same time.

  • How do I calculate the maximum demand of the premises?

    There is guidance in the IET Code of Practice for EV Charging Equipment Installation on supply adequacy (Maximum Demand) assessment. This information is critical to understanding if the EV charge point or Heat Pump can be supported by the network. There are different approaches to determining a site’s MD, including:

    • Use existing information – this is the best approach when there is available data on the specific loads in the house. However, this may not always be the case.
    • Determine loads installed – this approach takes diversity into consideration where appropriate. For this purpose there are different guidelines to assist installers, including:
      - Electrical installation design guide – calculations for electricians and designers
      - On-site guide BS 7671:2018 – IET wiring regulations, 18th Edition

    Please contact the IET if you have further questions on the guidance.

    Some installers chose to post their customers an internet-connected monitoring device which connects to the customer’s internet router and clamps a split Current Transformer (CT) around the supply meter tail. Data is then remotely collected over two weeks at ten minute intervals, before being analysed to arrive at an accurate maximum demand without the need for a site visit.

  • What is a cut-out?

    A cut-out is a piece of electrical equipment that forms the link between your network operator’s electricity cable and the internal wires in your property. To identify what cut-out your property has and its associated rating, you will first need to identify it and potentially speak to your local network operator. Certain older cut-outs are inadequate and will need to be upgraded by the network operator. Please see our Cut-out rating guidance for electric vehicle and heat pump installers for more information. It can also be found in our Resource library.

  • How do I identify issues with the property’s cut-out?

    There is guidance available from the National Association of Professional Inspectors and Testers (NAPIT) on identifying issues with distribution network equipment. Installers sometimes ask for photographs prior to site visit to save resource. One should also read the aforementioned ENA Guidance document.

  • How do I identify the rating of the cut-out fuse?

    The rating of a cut-out fuse can usually be identified through a visual inspection of the cut-out. In some cases a network operator may have to identify the rating of the cut-out fuse as it is not always obvious. Please see notes in the new process for further guidance.

  • What is an MPAN and where can I find it?

    The MPAN (Meter Point Administration Number) can be found on a copy of the electricity bill for that supply.

  • What is an import or load limiting device?

    An import or load limiting device is a piece of hardware and/or software that limits the demand (i.e. the amount of current drawn) by a premises. In the case of an EV charge point/Heat Pump, this can be thought of as an EV/HP curtailment scheme. This must be factored into calculations when populating the EV/HP application form. It is the responsibility of the installer to ensure that that the Maximum Demand(s) stated are correct, factoring in the effects of any load limiting devices or EV/HP curtailment schemes. The load limiting device must also “fail safe”, i.e. when it is not operating or has failed, it must not result in the limitations of the connection being exceeded.

  • Clarification of load limiting devices for residential properties

    When the existing Maximum Demand of a premises is above 60A, i.e. prior to any new electric vehicle chargepoints or heat pumps being installed, network operators will permit a “Connect & Notify” installation for a new EV chargepoint or Heat Pump under the following conditions:

    • No issues with the existing connection (i.e. no safety concern, looped supply, unknown cut-out capacity, unmetered supply, insufficiently sized cut-out, etc – see Notes 1-6 on combined flowchart)
    • The installation of the new device (EV chargepoint or Heat Pump) is installed with an EV/HP curtailment scheme such that, whenever that device is activated (i.e. drawing current), the overall MD of the property is limited to 60A or less.

    This clarification will be included in the updated combined flowchart and application form along with additional changes in the coming months.

    Please note that this FAQ and associated clarification only refers to import, i.e. EV/HP acting as a demand only, and it is not applicable to V2G/grid export limitation, which is covered by ENA Engineering Recommendation G100.

  • Where can I find guidance on installing an electric vehicle chargepoint?

    The IET’s Code of Practice on Electric Vehicle Charging Equipment Installation provides guidance and outlines best practice for installers on a range of installation issues. It also specifies that in the case of dedicated EV charging equipment installed at any site the installer shall ensure that the appropriate network operator has been notified of the installation within one calendar month of the installation.

    The IET Code of Practice highlights the installer’s responsibility to:

    • Assess the adequacy of the supply capacity for the new Electric Vehicle load plus any existing load, before installing the charging equipment
    • Assess the adequacy of the earthing, before installing the charging equipment
    • Notify the network operator of the installation once completed
  • Where can I find information about wayleaves?

    Information about wayleave payments and who to contact if you have a query related to this can be found on our Equipment on your land page.