ESB Networks planned to complete the electrical connection of Inishbofin to the Irish national grid via a new submarine cable from Port na hAiUe on the island to Cleggan on the Galway coast by November 1998, as part of the EU co‑funded Inishbofin/Clare Island phase of its island interconnection and network-upgrade programme.
For the late‑1990s Inishbofin/Clare Island grid-connection phase, which includes the Inishbofin submarine cable between Port na hAiIle on Inishbofin and Cleggan on the Galway coast, the European Union committed funding to cover half of the project’s cost, providing grant support alongside ESB’s investment to make the submarine cable scheme financially viable.
For the Inishbofin–mainland submarine power link (delivered together with the Clare Island connection), ESB Networks used approximately 20 km of heavy-duty three-core, EPR-insulated, double wire–armoured submarine cable with 120 mm² copper conductors, manufactured at the Pirelli plant and rated at over 300 amps, indicating Pirelli’s role as the cable supplier for the project phase connecting Inishbofin to Cleggan on the Galway coast.
As part of the Inishbofin–Clare Island grid connection project, ESB undertook major upgrading of the onshore electricity networks on the islands and adjacent mainland, strengthening lines in conjunction with a general move from 10 kV to 20 kV networks and installing higher‑rated insulators to reduce salt‑related arcing, with ESB regional staff carrying out the onshore works.
The submarine power cables serving Inishbofin and Clare Island were fully laid by a contracted laying vessel, which collected approximately 20 km of heavy‑duty three‑core, EPR‑insulated, double wire‑armoured cable from the Pirelli plant and installed it on the seabed at a rate of 1.5–3 km per hour, using 120 mm² copper conductors rated at over 300 amps.
Landfall works for the Inishbofin submarine cable, running from Port na hAiUe on Inishbofin to Cleggan on the Galway coast, were completed by offloading cable offshore, floating it ashore, hauling it onto the beach, then burying and encasing it in concrete above the shoreline and applying special protective coverings for 100–200 m below the shoreline.
In the late 1970s to early 1980s, the Irish government requested that ESB investigate providing mainland-standard electricity supply to the islands of Inishturk, Clare Island and Inishbofin, leading ESB to study the feasibility and costs of connecting these islands to the mainland grid by subsea cable; at that time the analysis concluded that such grid connections were not feasible.
| County Galway | County Galway | |
|---|---|---|
| Landfall | Port na hAille, Inishbofin Island, County Galway | Cleggan, County Galway |
| Grid Connection | — | — |
County Galway
County Galway