Connecting Mini-Generation

In general these generators are designed to switch off when the electricity network supply is disconnected.

This is a safety feature of the protection systems installed within these devices. This feature protects the generator itself and also ensures the generator does not create a potential hazard by making the external electricity network live in a fault situation.

It is however possible for certain generators to be installed in such a way that they can be operated when the electricity supply is disconnected. In order to do this the premises must be physically isolated from any connection to the external electricity network. This is a safety requirement under the NSAI Wiring Regulations and requires a changeover switch and other alterations to internal wiring within the premises in order to permit safe operation of such generation. More information on these generators, including what would be required to enable this in your own premises, can be obtained by contacting a registered Safe Electric electrician, a suitable generator installation company or by contacting a generator equipment manufacturer directly.

The cost of your bill may fall because you may not be drawing as much power from the electricity network as previously. However, there is no change to your standing charge which remains the same.

Yes. You can connect a Mini-Generator in parallel with ESB Networks provided the requirements in the document  "Conditions Governing the Connection and Operation of Mini-Generation" are met.

To familiarise yourself with the process, please read the document Conditions Governing the Connection and Operation of Mini-Generation, (Download PDF | 503 KB).

There is an application fee of €795 plus VAT@23% (€977.85) to apply for a Mini-Generator connection. This fee covers a technical assessment of the Mini-Generator on the electricity network. The technical assessment may determine that there are ESB Networks connection works required to connect the Mini-Generator, the charge of which is to the customer. Any works required will be covered in the connection offer and a down payment request will issue with the connection offer. Payment of the down payment request is required in order to accept the connection offer and proceed with the connection of the Mini-Generator.

Below is a non-exhaustive list of examples of ESB Networks connection works which may be required in order to connect a Mini-Generator to the electricity network:

• Uprate of a transformer;
• Uprate of a section of overhead line or underground cable

No. According to the eligibility criteria introduced by the Commission for Regulation of utilities (CRU), if you are eligible for a smart meter, you need a smart meter to be paid for what you export back to the network. You will not be eligible for deemed export payments.

Yes. 

Micro-Generation can be applied for using a simpler "inform and fit" process by submitting an NC6 Form (Download PDF | 144 KB) to ESB Networks. This application process can be used to connect a generator with a maximum export of 6kVA at single phase or 11kVA at three phase.

Mini-Generation enables the connection of inverter connected generators up to a maximum total of 17kVA at single phase or 50kVA at three phase. Applications in this range can be made by submitting an NC7 form (Download PDF | 532 KB) to ESB Networks and following the application process.

Small Scale Generation enables the connection of generators outside of those covered by the processes above and up to a maximum total of 200kVA. Inverter-connected generator applications in this range can be made by submitting an NC8 form (Download PDF | 97KB) to ESB Networks and following the application process. Note that for synchronous generator connections above the level covered under Micro-Generation and up to 200kVA, the NC5 form (Download PDF | 530 KB) is required to be submitted.

The largest generator which can be installed and applied for under the current Mini-Generator Application Form (NC7) is an Inverter Connected Generator up to 72 amperes (≈17kVA) single phase or 72 amperes (≈50kVA) three-phase. 

It is possible to install a larger generator under alternative application processes. For further information, go to Connect a Renewable and Embedded Generator.  

Under the Mini-Generation application process, once ESB Networks is in receipt of the completed Mini-Generation Installation Confirmation Certificate, we will update your MEC and notify your electricity supplier. As ESB Networks are not responsible for the purchase or sale of any electricity you will need to have an agreement with your Electricity Supplier to purchase the electricity exported.

For more information on how and when customers can expect to get paid for export, please see CRU’s website at this link.

ESB Networks DAC are not responsible for the purchase or sale of any electricity. This is a matter for a customer and their electricity supplier.

For more information on how and when customers can expect to get paid for export, please see CRU’s website at this link.

For more information on Clean Export Tarriffs, please see CRU's website at Clean Export Tarriffs

Eligibility criteria for payment for export to the grid are determined by CRU. For more information on the eligibility criteria, please see CRU’s website at this link.

Where a change of meter is required in order to measure export, the meter will be scheduled for replacement under the current phased Smart Metering Rollout Programme.

Currently the Smart Metering Rollout Programme is working to replace standard single phase domestic 24-hr meters (MCC01). Under the current rules announced by the CRU if you are eligible to receive a smart meter during this phase of the rollout, then you will need a smart meter to be paid for export. Where customers are eligible to have a smart meter installed, ESB Networks will endeavour to install a smart meter within four months of the completion of a valid Mini-Generation NC7 application process. ESB Networks will be in contact in advance of your smart meter exchange. For more information on the Smart Metering Rollout Programme please see this link.

If you are not eligible to receive a smart meter during this phase of the rollout, then CRU has outlined that you may be paid based on a deemed export calculation until such time as a suitable smart meter is available for your connection type and installed as part of the phased Smart Metering Rollout Programme. For more information on this, please see CRU’s website at this link.

While we do not require evidence of Planning Permission to process a Small Scale Generation application, the onus is on the customer to ensure that the correct PP is in place as per the local county council. 

Yes, customers that previously applied for MEC=0 can still apply for Mini-Generation. If the previous application process has been completed, including a successful witness test, the generator can continue to operate under MEC=0 rules until the Mini-Generation application is finalised. However, if the non-exporting application process is not complete then this will need to be cancelled and a new Mini-Generation application submitted. In this case the generator cannot be connected until the witness testing is successfully completed.  

Yes, it is acceptable to have a Total Installed Inverter Capacity (TIIC) greater than the site MEC in certain circumstances by using a suitable Export Limiting Scheme (ELS). When the Total Installed Inverter Capacity is greater than the MEC, you are required to provide a Manufacturer’s Export Limiting Scheme (ELS) Product Declaration Form – you can find the template here. This needs to be completed and signed by the Manufacturer. Following submission of the application, the level of MEC available on the existing network, or an outline of the reinforcement work required to enable a specific MEC, will only be determined by a specific technical study on the local network which will be completed as part of the process.

The results of these findings can be impacted by variables such as distance from the transformer, available capacity, harmonics, potential imbalance, etc. As such we advise customers to await the completion of this study and receipt of their connection offer prior to fully committing to the final details of their installation.  

Yes, we can accommodate Mini-Generation NC7 applications at the same time as an MIC change, once the MIC change application has also come in through the relevant application channel and is in process. Further information may be found at Changing Your Level of Supply 

The Mini-Generation application will, however, progress only in parallel with the MIC increase and will depend on its progress and completion.  

Note: An MIC increase does not guarantee that you will the able to contract the full, requested MEC. This can only be determined by a specific technical study on the local network which will be completed as part of the process and will inform the MEC available, or an outline of reinforcement work which may be required to enable a specific MEC. The results of these findings can be impacted by variables such as distance from the transformer, available capacity, harmonics, potential imbalance etc. As such we advise customers to await the completion of this study and receipt of their connection offer prior to fully committing to the final details of their installation.

If the generator either never parallels with the electricity network, or only parallels for 3 minutes when turning on/off and no more than 5 minutes a month, then they are just noted on the application form as existing Generation. The installed generation capacity associated with this generator is not included when assessing the overall level of generation installed on the site for the purpose of Mini-Gen, SSG or for assessment of Total Installed Generation. 

Limited Maximum Export Capacity (LMEC) is the term used for the Mini and Small Scale Generation connections which are available in  those areas of the electricity network which  have a high penetration of exporting generator connections already in place relative to the available electricity network capacity at higher voltage levels in that location. This means that at present there is limited capacity for further connection of generation export. 

In order to ensure continued grid safety, stability and reliability we need to offer this connection type in areas with limited electricity network capacity.  

The Limited Maximum Export Capacity (LMEC) restricts the amount of export available from new Mini and Small Scale Generation to no more than 6KVA (single phase), 11kVA (three phase), regardless of the size of the system installed. The limits on the size of the generator which can be installed will be determined by the technical characteristics of the local connection. In general, Limited Maximum Export Capacity (LMEC) connection offers will require the installation of an Export Limiting Scheme (ELS) to limit the system export to the permitted Maximum Export Capacity (MEC) to no more than 6KVA (single phase), 11kVA (Three Phase). More information on ELS can be found here.  

If your application falls into an LMEC area an Export Limiting Scheme (ELS) will be mandatory. More information on ELS can be found here. An ELS scheme can be implemented using either a Reverse Power Relay or an ELS control system. For an ELS Control System you will be required to provide a Manufacturer’s Export Limiting Scheme Product Declaration Form – you can find the template here. This needs to be completed and signed by the Manufacturer. 

LMEC connection offers require the system export to be limited  to the following Maximum Export Capacities:

• 6kVA if the connection is single phase,
• 11kVA if the connection is 3phase connecting to the LV or MV network. 

Currently Limited Maximum Export Capacity offers are only available to applicants' seeking connection under the mini generation and the small-scale generation schemes.  

This information can be found on the ESB Networks Availability Capacity Map webpage and with explanation of the map in the Capacity Map FAQ’s. 

Electrification will generally require the uprating of most substations and such uprated substations will have more capacity to accommodate generation export, both because the Transformers will be larger but also because of the increase in local load which will also absorb generation.  Planning and delivery of these projects will take a number of years to complete.

Additionally, dynamic management of load and generation will be a feature of future network operation and this is also likely to facilitate increased generation export. 

The Generation Capacity Map on our website will be updated as and when available capacity changes throughout the country.