RPS’ Belfast office has helped Islandmagee Storage Limited to gain planning permission for a 500 million cubic metre gas storage facility in salt caverns one mile beneath Larne Lough.
Planning approval has just been announced by Alex Attwood, Minister for the Environment, for a £400 million gas storage facility capable of storing up to 500 million cubic metres of natural gas.
The project is the first of its kind in Ireland, where natural gas is stored in "caverns" created within a deep underground layer of salt (halite) approximately one mile beneath the bed of Larne Lough.
The facility, which will have its above ground facilities located adjacent to Ballylumford Power Station in Islandmagee, Co. Antrim, will make a significant contribution to the security of gas supplies for the whole island of Ireland. Ireland is dependent on natural gas for around 65% of its electricity generation and currently imports 90% of its gas requirement via a single pipeline from Scotland.
When completed, the project will be able to store enough gas to satisfy Northern Ireland’s peak winter demand for around 60 days in the event of an interruption to supply. It also has the potential to reduce volatility in energy prices – with customers such as power stations or gas suppliers having the option of purchasing gas for storage when prices are low for use or sale when prices are higher.
The storage caverns are constructed by drilling boreholes, or "wells" into the salt layer, some 1,600 metres below the surface. Sea water is then pumped down each well, under carefully controlled conditions, to dissolve the salt and create an empty chamber - a process known as "leaching". The seawater containing the dissolved salt is returned back to the surface and is then pumped around 3.5km across the peninsula of Islandmagee, where it is then discharged back into the sea at via an outfall extending around 450 metres into the North Channel. The water depth (27 metres) and strong tidal currents allow the brine to be rapidly diluted to near-background concentrations within a short distance of the outfall.
Larne Lough and its surroundings hold a number of important environmental designations, including a Special Protection Area and several Areas of Special Scientific Interest as well as a newly-proposed marine Special Area of Conservation at the nearby Maidens.
RPS’ Belfast office initially assisted the project’s developers Islandmagee Storage Limited to gain the necessary statutory consents from NIEA and Planning Service to undertake preliminary seismic surveys at the site in 2007 and subsequently prepared the Environmental Impact Statement and secured planning approval for the project.
RPS’ involvement continues, with the team now aiding Islandmagee Storage Limited in their acquisition of the necessary marine consents for the offshore elements of the project, as well as providing consultancy services, such as noise monitoring and traffic management, during the first phase of construction.
Work at the site is due to commence shortly, with the first well expected to commence drilling in Spring 2013. Subject to raising full funding, the first gas storage operations could begin in 2017, with construction of all seven caverns completed by 2020.