IN 1955, in the heyday of Rural Electrification, ESB investigated the possibility of supplying some of the most populous islands off the Irish coast. On the basis of economic studies carried out, it was concluded that the Arranmore, Co. Donegal and Valencia and Bere Islands off Kerry were the most promising islands for extension of mainland supply. In particular, in relation to Arranmore island, (pop.1,400) it was noted that ‘’ there is likely to be a good response from the islanders as most of them are used to the amenities of town life.’’
Accordingly ESB bravely and innovatively in 1957 set about extending supply to the these islands. That cable used provided excellent service overall and in the case of one island provided 45 years of fault-free operation in 20m depth of saltwater.
The overhead networks on the islands were constructed to a high strength specification to provide a reliable electricity supply to islanders in circumstances of continuous exposure to severe Atlantic gales and salt spray contamination.
A report concluded that supply to the Aran Islands, Tory Island, Inishbofin, Clare Island and Cape Clear would be uneconomic and that the best solution at that time would be to use local diesel generators to supply these islands.
In the 70’s and early 80’s ESB built networks on these islands and supported the island communities as technical consultant to the Island Co-ops in the running of the diesel generation system and later on as provider of local island based complete diesel electricity generation and distribution systems, designed to provide very high reliability of supply. This involved a substantial capital and resource commitment from ESB.
Between the 60’s and 80’s ESB extended mainland supply to Spike Island, Long Island, Hare Island and Whiddy Island. Using submarine cable an overhead lines supply was ‘’stretched’’ to Dursey island and Sherkin island.
In the 1990’s, following large load growth on the bigger islands, the need to provide greater capacity to cater for tourism and local industry related growth, and to provide a high standard economical electricity supply well into the 21st century, ESB sought and obtained EU funding for extension of 20kV rated mainland cable to the three Aran islands, Inishbofin, Clare Island and Cape Clear and for refurbishment and conversion of the existing island overhead networks to 20kV standard as appropriate. Overall ESB oversaw investment of approximately €10M in this programme which involved the laying of 1,200 tons of heavy duty submarine cable over a distance of 55km. Consider-able reinforcement work was also undertaken on the mainland networks to provide a high quality reliable supply.
For the smaller more remote islands of Inishturk and Tory island, ESB has continued to invest and improve the local generation and network facilitiesIn the late 1990’s, a Goverment interdepartmental committee recommended that ESB seek EU funding for mainland supply to a further number of smaller offshore islands.
Since late 1999 the Department has provided funding for the extension of supply to 14 islands (3 in Mayo, 3 in Donegal, 6 in Galway and 1 each in Sligo and Limerick). This programme of work is set to be completed by the end of 2003.