Interconnector is not just about electricity, it's about power

John Fitzgerald: if Ireland is to generate 40% of its electricity from wind we need to double our interconnection with Britain and France

An engineer measuring voltage or current. Having links with less “windy” systems means that surplus power can be exported when the wind blows in Ireland
An engineer measuring voltage or current. Having links with less “windy” systems means that surplus power can be exported when the wind blows in Ireland

On Wednesday the EU announced major funding for a new electricity interconnector to be built between Ireland and France, which is expected to be operational by 2026. This interconnector is not only important for the electricity system, but it will be vital in helping the Republic meet its goals on tackling climate change.

The first electricity interconnector between the North and Scotland was inaugurated in 2002. The second interconnector, running over 250km between Meath and Wales, was opened in 2012. Together these links have been important in enhancing the security of the electricity system North and South, as well as reducing the cost of electricity for consumers.

The growth in wind generation over the past 20 years has greatly increased the importance of connecting the Irish electricity system to the British and the wider EU system.

As our wind turbine capacity has increased, the value of interconnection has also grown. Already on windy summer nights these turbines could potentially provide all our electricity needs.

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However, to make the overall system work, and ensure a stable voltage, along with current that alternates exactly 50 times a second, significant traditional gas or coal-fired generation is also needed. Increasingly this means that when the wind blows some wind generators have to be shut down because the electricity system cannot use their output – it goes to waste.

Having links with less “windy” systems means that surplus power can be exported when the wind blows in Ireland and, when it does not, power can be imported. This minimises total emissions of greenhouse gases from linked systems, and it also minimises the cost of electricity for consumers in both jurisdictions.

Adequate links

An ESRI study in 2009 suggested that if Ireland was to generate 40 per cent of its electricity from wind, which is the objective for 2020, we would need double the amount of interconnection with Britain or France that we have today. In the absence of adequate links we are wasting valuable wind energy at peak times, and losing out on the opportunity to buy cheaper power abroad in times of calm weather.

However, if we are to meet our climate targets by 2030 we will need to almost treble our wind output. This will mean that some of the time wind power will amount to over 100 per cent of electricity used in Ireland.

To make a system with that level of wind power work sustainably we need a major increase in interconnection to other electricity grids. This is where the new link to France will come in. However, even this connection will not be enough if, as envisaged in the Government’s Climate Action Plan, we are to generate 70 per cent of our power from renewables by 2030.

It is no accident that this longer and more challenging interconnector is being favoured over another link to Britain. With Brexit it is difficult to tell where the British electricity market is going, especially as its links to the rest of the EU electricity market are relatively weak.

Also, given that Britain has similar weather patterns to ourselves, and is also increasing its own wind-generation capacity, they may also have their own excess at the same time that we have surplus wind power to sell. So it makes sense to link to a network with rather different weather patterns to ourselves.

EU grant

In Europe normally the cost of interconnection is shared between the electricity systems that are being linked. However, while an EU grant paid for about 20 per cent of the €600 million cost of the Welsh interconnector, the rest of the cost was paid for by Irish consumers. The British authorities did not feel that the value for British consumers warranted a significant contribution.

The cost of the interconnector to France seems likely to be less than twice the cost of the Welsh link in spite of the fact that it will have 40 per cent greater capacity and be more than double the length. An EU grant will cover about 55 per cent of its €950 million cost. The remainder of the cost will be shared, with Ireland paying over €250 million and France something under €150 million.

The result is that Irish consumers will get a bigger and longer interconnector into the integrated EU market for much less than the cost of the last link to Britain.

While the generous EU contribution reflects the wider benefits to the union of developing an interconnected electricity system, it is also a very concrete expression of a high degree of solidarity within the EU at the time of Brexit.