GAS SUPPLY:With Europe's gas fields near depletion, Ireland must face the risks of not having a secure gas supply

DEPLETED GAS fields are becoming increasingly important commercial assets, offering further business opportunities and creating a means of improving our fragile energy security.

Any debate over the Corrib Gas field should not lose sight of this, while also bearing in mind the stark economic risks of not having a secure gas supply, according to the Ecology Foundation, an Irish green business group.

It has highlighted the fact that, since we're at the end of the pipe, with 90 per cent of our gas coming via interconnectors with Britain, we should bear in mind that our neighbour almost ran out of gas in February of this year. Its saving grace - and probably ours, too - was the depressed state of the economy, resulting in reduced demand from industrial users, the UK shadow energy secretary later revealed.

If we're to prevent shortages, we should look ahead to what can be done with the Corrib field in 20 years' time, once it is more or less empty, according to Mark Rutledge, the Ecology Foundation's country director for Ireland. As with our previous main source of gas in Kinsale, which used to meet about half of our needs but now meets less than 10 per cent of demand, it may have the potential to become a gas reservoir.

Dublin-based, AIM-listed exploration firm Island Oil & Gas is currently looking at the potential to store gas in depleted gas seams at its Old Head and Skull fields in the Celtic Sea.

This would involve leasing the space to a joint venture partner, who would buy gas during the summer, when it's cheap, and sell in the winter, when price and demand is at its highest.

"It's a low-risk, medium-reward option. It's a way of monetising our assets, it provides cashflow, which is vital at the moment, and it could be profitable over 20 or 30 years. We're making sure it's feasible and we've had initial discussions with partners and customers," the company's chief executive, Paul Griffiths, said.

Another alternative would be to effectively create an energy hub in northwest Mayo, Rutledge claims. "Once Corrib has declined, it'll afford us a huge opportunity to use the empty gas fields as a carbon sequestration store. This would make north Mayo an excellent location for heavy energy industry because carbon sequestration will be a huge determining factor for the location of industry once full carbon auctioning comes into the traded sector.

"As well as providing a welcome economic boost, the same infrastructure could be used as the service centre for future offshore tidal, wave and wind farms dotted around the west coast. Belmullet could become the Aberdeen of the green energy sector in the future," he adds.

A testing facility for wave and tidal energy with a link to the electricity grid is due to be in place by early next year, according to energy minister Eamon Ryan. Building on this infrastructure, while also bearing in mind various operational technology and software will be needed to monitor and run it, would boost skilled employment in engineering and associated roles.

Since our climate already benefits from warm Gulf Stream waters, another option may be to tap into geothermal energy through the Corrib gas wells, once they are empty.

The future energy division of Austrian oil company OMV has recently spent €2 million looking at the potential to do so there, where about 1,000 existing oil- and gas-producing wells are depleting at a rate of about 30 per year.

OMV is investigating whether suitable wells can be adapted and retro-fitted with a device called a borehole heat exchanger. This can be used to provide heat and hot water to households in the winter, also providing a means of cooling their homes in the summer months, using a heat exchanger that is more energy efficient than existing ones.

According to the Geothermal Energy Association of Ireland, this type of energy could provide as much as 15 per cent of Dublin's hot water and heating. Given the high proportion of CO2 emissions generated by heating homes and other buildings, geothermal therefore offers the means to reduce these substantially, providing the heat and hot water can be piped to where it is needed.

Until one or all of these opportunities can be realised, there are mounting risks to Ireland's energy security, Rutledge says. Russia's Gazprom supplies about a third of Europe's gas, but it is struggling to keep up with demand, he argues.

As we languish at the end of the European pipeline, strategist Christophe-Alexandre Paillard at France's Ministry of Defence has claimed Gazprom's three biggest gas fields are 50 per cent, 65 per cent and 80 per cent depleted, respectively.

Our single existing gas storage facility at southwest Kinsale could meet about a third of our daily needs, and Ireland's position on the periphery of the European network means it is more vulnerable than any other EU country. Britain faces "very serious risks" in terms of energy security, according to consultants CapGemini, suggesting our position is even worse.

"The Irish Government has made a commitment to renewables energy and it is hoped that renewables will become the main source of power for Ireland.

"However, while we transfer to renewables our reliance on imported fossil fuels cannot be continued," says Rutledge. "Corrib gas is the bridge to the low-carbon economy and the bridge to energy security."