What are Interconnectors, and what importance do they have for Britain?

An Interconnector is a high-voltage cable that allows electricity to be transferred from one country to another. The cables can run either under the sea, underground or as part of an overhead line. Great Britain has a number of individual Interconnectors with other countries currently in operation, with a combined capacity of 5GW:

500MWMoyleNorthern Ireland
500MWEast – WestRepublic of Ireland

Power prices are generally more expensive in Britain compared with mainland Europe due to a number of factors: we are a net importer of gas[1] which can lead to higher gas prices and subsequently higher power prices; and we tend to have higher costs of production as we have an additional Carbon Price Support (CPS) cost on top of the EU Emissions Trading System (ETS) price. As such, Great Britain tends to be a net importer of electricity across the interconnectors from mainland Europe. In 2019, Britain imported c22TWh of electricity from our interconnectors in mainland Europe, while exporting c1TWh to the Republic of Ireland[2].  

There are an additional 5GW of interconnectors planned over the next decade[3]. While Britain will continue to import in the short to medium-term, there may be a change in trend given some of the changes to our neighbouring countries: France have plans to close a number nuclear plant, aiming to cut its % share of electricity output by 25% by 2035; and Germany want to close all coal plants by 2038. Together with the fact that Britain is looking to expand its offshore wind capacity (LINK to Offshore Wind blog), which is a cheap source of power and one that we have comparative advantage of given our geographical location, we could see Britain becoming a net exporter of electricity, and our power price compared to mainland Europe could reduce.


[2] https://www.bmreports.com

[3] Connection registers, reports, and guidance | National Grid ESO Interconnector Register 19th Nov 2020, Interconnectors with Consents approved/and or Under Construction. Import Capacity volume.


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