The Irish TSO, EirGrid, is planning to publish indicative Large Energy User (LEU) heatmaps to support transparency on the Irish transmission system’s capability to accommodate new large demand connections. Heatmaps for available capacity in generation and storage are not currently in the scope work for this project.
The LEU heatmaps will provide high‑level, locational insights into areas of the transmission network where capacity constraints may be more or less likely to arise under prevailing system conditions and planning assumptions. They are intended to support early‑stage engagement and informed decision‑making by stakeholders, including prospective connection applicants, while maintaining appropriate national context.
The heatmaps will be indicative and non‑binding in nature. The methodology has been developed to align with other similar analysis carried out internally. They will not represent firm or guaranteed connection capacity and will not replace existing statutory connection application, assessment, or decision‑making processes. Detailed technical studies and case‑specific analysis will continue to be undertaken through established national connection frameworks.
ESB Networks is the only DSO in Ireland and produces the capacity heatmap for the entire country. The capacity heatmap contains capacity information on all three-phase LV, MV, and HV DSO substations. It provides an interface that enables the easy identification of potential transformer capacity in the vicinity of a site. An Excel file is available to download from the download section on this page.
The availability capacity heatmap provides an indication of available transformer capacity at the substation level and all voltage levels for new demand and generation customers. It is a user-friendly and interactive map that shows how much demand or generation can be added to a substation without reinforcement. It empowers potential customers and gives them a better understanding of where connection is possible.
In the map, HV substations are classified into three categories corresponding to the connection voltage, i.e. 110 kV, 38 kV, or MV.
The map also gives the location and available demand capacity for all three-phase MV/LV substations. LV data capacity is in the range of customers looking to connect demand less than 500 kVA, typically small businesses, farms, and small community projects. If the indicated capacity meets customer’ needs, then it can be reasonably assumed no new substation development is required. However, site-specific details, such as proximity and physical access, could still be an overarching limiting factor.