At ESB Networks we are committed to improving the experience of our customers. As part of this commitment, we have developed our interactive availability capacity heatmap. It contains capacity information on all our 3-phase LV, MV and HV DSO substations. It provides an interface that enables the easy identification of potential transformer capacity in the vicinity of your site. An excel file is available to download from the download section on this page.

We envisage that the map will be used to inform initial discussion between ourselves and our customers. Although we have taken steps to ensure the accuracy of the map, it cannot replicate the level of accuracy provided by the detailed assessment carried out as part of the formal application process.  Please read the accompanying notes and important details section to understand what the map does and does not provide.

If the availability capacity heatmap indicates that there is insufficient capacity to accommodate your development, please contact us to discuss the next steps. We will always work with customers to find solutions.

Generation customer queries should be directed to  DSOgenerators@esb.ie

Demand customer queries should be directed to innovationfeedback@esbnetworks.ie

What can I learn from the map?

• The availability capacity heatmap provides an indication of available transformer capacity, at substation level and at all voltage levels, for new demand and generation customers. It is a user-friendly and interactive map that shows how much demand or generation could be added into a substation without reinforcement. It empowers potential customers and helps them have a better understanding  as to where connection is possible.
• In the map HV substations are classified into three categories corresponding to the connection voltage i.e., 110kV, 38kV or Medium Voltage (MV). 
  
• The map also gives the location and available demand capacity for all 3 phase Medium Voltage to Low Voltage (MV/LV) substations. The LV data capacity is in the range of customers looking to connect demand less than 500kVA. This scale would be of most interest to small businesses, farming, and small community projects. If the indicated capacity meets your needs, then you can be reasonably assured no new substation development is required. However, site specific detail such as proximity and physical access could still be an overarching limiting factor.
• Available capacity for LV generation is not specified because of additional considerations that are mainly site specific.
• The pins on the map are colour coded by ranges of available capacity which can be separately filtered. Filtering can also be independently applied by voltage level.
  
  

How do I know which substation to review for my site?

• We recommend using the Location Finder tool by clicking on the icon to the right of the map.
  Look for this symbol:

• Here you can type your place name, or Eircode and it will show the stations closest to the location. Please ensure you have selected the relevant connection voltages and available ranges in the filters section on the left or it may not return results.
• For LV substations, use the map to locate your own site and then find the nearest LV substation to it. Typically, a substation must be within 300m or less to be suitable for connecting at LV otherwise a new substation must be provided nearer to you. The pop-up box also shows the parent HV substation that supplies the LV substation. Also check this for available capacity. 
• For MV connection (greater than or equal to 500kVA) locate the nearest LV station as in the previous paragraph and the parent capacity will also be shown. 
  
  

Does the capacity available value mean I can connect the amount shown?

Not necessarily. There are many site-specific issues and detailed technical checks that must be completed to give that assurance and they can only be completed as part of an application. Below are some of the factors that influence the answer: 

• Am I the first to apply? All connection offers are provided on a first come first served basis so other customers may have applied ahead and used a proportion of the available capacity.
• Proximity to the substation: typically for LV, you must be a maximum of 300m from the substation and much closer for the higher level of LV capacity. For 38kV and MV circuits, capacity is not assured, and new lines may need to be constructed or existing one upgraded. 
• HV substations are sometimes a parent supply to other downstream substations. In cases where the parent substation has limited capacity then all child substations will be curtailed by that limit. Furthermore, if just one child substation absorbs all the available capacity then that will result in no spare capacity for the other child stations. This form of interaction requires continual re-assessment to ensure no system overload occur.
• A similar interaction can occur on circuits where apparently available capacity cannot be contracted because of customer increases on other circuits which share a common source with a capacity limit.
• Generation, at all voltages, is particularly onerous due to the limited latitude to accommodate the associated voltage rise. This has an acute effect on the necessary proximity to a substation.
• For ECP generation connections, the capacity available may differ depending on customers accepting or withdrawing their connection study offers during each batch of studies.
• Capacity available is also influenced by disturbing load such as flicker and harmonic emissions.
• The stated available capacity may exceed the maximum rating for an individual network component for example standard circuit connection capacity. In such cases, a connection will be constrained by the network component and therefore will not be able to avail of the full value indicated.
  

How has the data been produced? 

The data has been produced by an analysis of the available transformer capacity, existing loads and contractual commitments to new customers. Detailed assessment aspects, necessary for connection offers, such as upstream circuit capacity and service contingency requirement are not included. 

What are the available capacity figures based on? 

• Station capacity, as of December 2023.
• Base load information comes from Special Load Readings, 2023/2024 which include 2023 Summer Valley load used in the generation capacity preparation.   
  
• Demand calculation incorporates demand contracts and offers up to mid-June 2024
• Generation calculations incorporates generation contracts and offers up to June 2024
  

How often is the availability capacity map updated? 

As part of ESB Networks strategy, the objective is to update the map quarterly.  

Are the substation locations accurate? 

HV substation locations are only indicative. The exact locations of MV/LV substations are provided.

How long does a connection take? 

In general, where HV substation capacity is adequate, MV connections up to a maximum of 10MVA will entail construction of overhead line or new underground cable network, associated civil works and minor station works only and typically do not require planning permission. These would not be expected to take longer than 6-9 months. However, any instances requiring significant station work such as the installation of a new transformer or MV switchgear will require increased time, and possibly planning permission or necessary permits and would typically be expected to take approximately 2-3 years.

LV connections alone are usually completed within 6 months of application.

Generation connection information:  Enduring Connection Policy (ECP) (esbnetworks.ie)

What other important points should be kept in mind about the data in the map? 

• The map does not replace a full formal application in determining network capacity.  
• The map does not provide capacity figures for the final connection from HV substation to customer premises. Such connections will need to tap into the existing MV (10kV or 20kV) network. Capacity availability is subject to many variables and an assessment is necessary.  
  
• In some cases, the available capacity shown in the demand map may already be contracted to individual customers but is not currently being fully utilised.
• The information provided in the generation and demand maps does not guarantee the same capacity is available in the upstream DSO networks.
• Any increased load on the distribution system will impact on the upstream transmission system and reinforcements may be required on the transmission system in order to cater for these loads. This will be separately assessed by the TSO. 
• An individual connection cannot be greater than the capacity of an individual transformer.  In the case of 38kV and MV, the available capacity shown is the total of all transformers in the substation at the respective voltage.  Therefore, full capacity utilisation may, sometimes, only be possible with more than one connection. (Note, a single premises cannot have more than one connection).